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Testing for Restricted Stochastic Dominance under Survey Nonresponse with Panel Data: Theory and an Evaluation of Poverty in Australia

Matthew J. Elias e61 Institute, Sydney, Australia.    Rami V. Tabri  Corresponding author. Department of Econometrics and Business Statistics, Monash University, Melbourne, Australia; Email: rami.tabri@monash.edu
Abstract

This paper lays the groundwork for a unifying approach to stochastic dominance testing under survey nonresponse that integrates the partial identification approach to incomplete data and design-based inference for complex survey data. We propose a novel inference procedure for restricted ssth-order stochastic dominance, tailored to accommodate a broad spectrum of nonresponse assumptions. The method uses pseudo-empirical likelihood to formulate the test statistic and compares it to a critical value from the chi-squared distribution with one degree of freedom. We detail the procedure’s asymptotic properties under both null and alternative hypotheses, establishing its uniform validity under the null and consistency against various alternatives. Using the Household, Income and Labour Dynamics in Australia survey, we demonstrate the procedure’s utility in a sensitivity analysis of temporal poverty comparisons among Australian households.
JEL Classification: C12;C14
Keywords: Empirical Likelihood; Panel Data; Stochastic Dominance; Nonresponse.

1 Introduction

This paper connects three bodies of literature:stochastic dominance testing, partial identification for incomplete data, and design-based inference for complex survey data (e.g. involving stages, clustering, and stratification). Although there is extensive literature on stochastic dominance testing (e.g., McFadden, 1989; Abadie, 2002; Barrett and Donald, 2003; Linton et al., 2005, 2010; Davidson and Duclos, 2013; Donald and Hsu, 2016; Lok and Tabri, 2021, among others), most methods fall short in practical applications because they assume complete datasets and rely on either random sampling or time series data processes. In empirical applications, data often come from complex socioeconomic surveys like the Current Population Survey, the Household, Income and Labour Dynamics in Australia (HILDA) Survey, and the Survey of Labour Income Dynamics, where nonresponse is common and data are not simple random samples. While the partial identification literature offers bounding approaches to address missing data issues (e.g., Blundell et al., 2007; Kline and Santos, 2013; Manski, 2016, among others), these often overlook the intricate designs of surveys, potentially leading to incorrect standard error estimations and subsequent distortions in tests’ size and power.

Conversely, the design-based inference literature accommodates survey design complexities but generally depends on designers’ handling of nonresponse who either posit point-identifying assumptions on nonresponse or specify a model of nonrandom missing data with reweighting/imputation (e.g., Berger, 2020; Şeker and Jenkins, 2015; Chen and Duclos, 2011; Qin et al., 2009, among others). Such assumptions may not hold when nonrespondents possess key characteristics influencing survey outcomes, such as income in socioeconomic surveys where the rich are often underrepresented (Bourguignon, 2018), rendering these inferences potentially misleading and not credible. It is also noteworthy that econometricians have considered design-based perspectives to inference in other contexts. See, for example, Bhattacharya (2005), who developed tests for Lorenz dominance, and Abadie et al. (2020), who focus on causal estimands in a regression framework. At the intersection of the three literatures is the testing procedure of Fakih et al. (2022). It is, however, limited in scope because it applies only to ordinal data generated from independent cross-sections and uses the worst-case bounds to account for nonresponse.

This paper bridges those bodies of literature. It provides the first asymptotic framework and inference procedure that integrates design-based inference with partial identification for handling incomplete data in econometrics, specifically for restricted stochastic dominance. Our approach effectively handles the survey’s complex design and the missing outcome data due to nonresponse. Importantly, it accommodates a broad spectrum of assumptions on nonresponse, enabling researchers to transparently perform sensitivity analyses of test conclusions by clearly linking them to various nonresponse scenarios.

To illustrate our approach, consider a data example on analyzing equivalized household net income (EHNI) data from the HILDA survey for 2001 (wave 1) and 2002 (wave 2). The objective is to detect a decline in poverty using the headcount ratio across a given range of poverty lines, [t¯,t¯][\underline{t},\overline{t}], by seeking evidence for restricted stochastic dominance: F2(y)<F1(y)F_{2}(y)<F_{1}(y) for all yy in this interval, where FjF_{j} represents the cumulative distribution function (CDF) for EHNI in wave jj. Strong evidence for this decline is usually sought through a test of H0:H_{0}: Not H1H_{1} against H1:F2(y)<F1(y)y[t¯,t¯]H_{1}:F_{2}(y)<F_{1}(y)\,\forall y\in[\underline{t},\overline{t}] and rejecting H0H_{0} in favor of H1H_{1} (Davidson and Duclos, 2013). A significant challenge with implementing this test in practice is that the achieved sample is incomplete:

Yi={(Yi1,Yi2)if Zi1=Zi2=1,(Yi1,)if Zi1=1,Zi2=0,(,)if Zi1=Zi2=0,fori=1,,n,\displaystyle Y_{i}=\begin{cases}(Y^{1}_{i},Y^{2}_{i})&\text{if }Z^{1}_{i}=Z^{2}_{i}=1,\\ (Y^{1}_{i},*)&\text{if }Z^{1}_{i}=1,Z^{2}_{i}=0,\\ (*,*)&\text{if }Z^{1}_{i}=Z^{2}_{i}=0,\end{cases}\quad\text{for}\quad i=1,\ldots,n,

where "*" indicates missing data, YijY^{j}_{i} and ZijZ^{j}_{i} are the EHNI and response indicators for wave jj respectively, expressed in 2001 Australian dollars. Nonrespondents in wave 1 are not followed up, equating nonresponse in wave 1 to unit nonresponse and in wave 2 to wave nonresponse. The unit nonresponse rate is approximately 33%, while for wave 2, it is about 8%; item nonresponse is disregarded for simplicity.

Consequently, without any assumptions on nonresponse the EHNI CDFs are only partially identified. The first panel in Figure 1 reports the survey-weighted estimates of the worst-case identified sets of these CDFs over a given range of poverty lines, assuming that the theoretically largest and lowest values of EHNI are 1000000 and -150000. Observe that while these sets are wide, they are maximally credible in that they reflect the inherent uncertainties that cannot be eliminated through less plausible assumptions. However, since one set is a proper subset of the other, they are uninformative for comparing F1F_{1} and F2F_{2} in terms of restricted stochastic dominance.

Refer to caption
Figure 1: Survey-weighted estimates: identified sets of F1F_{1} and F2F_{2}.

An alternative approach involves considering a range of assumptions on nonresponse, in the vast middle ground between the worst-case scenario (no assumptions) and the standard practice of assuming random nonresponse to point-identify F1F_{1} and F2F_{2}. This method allows consumers of economic research to draw their own conclusions based on their preferred assumptions. The subsequent panels in Figure 1 illustrate this by reporting estimates under various assumptions: U-shape bounds on nonresponse propensities conditional on EHNI (panel 2), the missing completely at random (MCAR) assumption for unit nonresponse combined with a worst-case scenario for wave nonresponse (panel 3), and a Kolmogorov-Smirnov neighborhood of the MCAR assumption for both nonresponse types (panel 4). While the sets in panel 3 are uninformative for comparing F1F_{1} and F2F_{2} using restricted stochastic dominance for the same reason as the worst-case scenario, panels 2 and 4 reveal that the upper boundaries of wave 2 identified sets are strictly below the lower boundaries of wave 1, presenting some evidence of a decline in poverty (i.e., H1H_{1}). Strong evidence for this decline under those nonresponse assumptions can be obtained by testing

H01:Not H11vs.H1:F¯2(y)<F¯1(y)y[t¯,t¯]\displaystyle H^{1}_{0}:\text{Not }H^{1}_{1}\quad\text{vs.}\quad H_{1}:\overline{F}_{2}(y)<\underline{F}_{1}(y)\;\forall y\in[\underline{t},\overline{t}] (1.1)

and rejecting H01H^{1}_{0} in favor of H11H^{1}_{1}. Here, F¯1\underline{F}_{1} and F¯2\overline{F}_{2} represent the lower and upper boundaries of identified sets for F1F_{1} and F2F_{2}, respectively, under the maintained nonresponse assumptions. The point being that rejection of H01H^{1}_{0} in favor of H11H^{1}_{1} implies rejection of H0H_{0} in favor of H1H_{1} under the maintained nonresponse assumptions.

We propose a survey-weighted statistical testing procedure for test problems of the form (1.1). Our approach employs estimating functions with nuisance functionals (e.g., Godambe and Thompson, 2009, and Zhao et al., 2020) in a general framework that covers a broad spectrum of nonresponse assumptions through specifications of the nuisance functionals – see Section 2.2 for some examples. This approach is helpful for performing a sensitivity analysis of inferential conclusions of the test under different assumptions on nonresponse within our framework. We illustrate this point in Section 6 with an empirical example of poverty orderings (Foster and Shorrocks, 1988) using data from the HILDA Survey.

The testing procedure employs the pseudo-empirical likelihood method (Chen and Sitter, 1999; Wu and Rao, 2006) to formulate the test statistic, applicable across any predesignated order of stochastic dominance and range. It compares the statistic against a chi-squared distribution’s quantile with one degree of freedom. To derive the test’s asymptotic properties, we have developed a design-based framework for survey sampling from large finite populations. We establish the test’s asymptotic validity with uniformity, and its asymptotic power against both local and non-local alternatives, achieving consistency against distant alternatives. However, the test exhibits asymptotic bias against alternatives that rapidly converge to the null hypothesis boundary, which is not surprising, as the test is not asymptotically similar on the boundary.

In developing our testing method, we primarily addressed unit and wave nonresponse for simplicity, though the method can be adapted to include item nonresponse. We have also limited our analysis to temporal pairwise comparisons between wave one and any subsequent wave, which is particularly useful when assessing restricted stochastic dominance of an outcome variable from the survey’s start to a later period. Extending beyond these comparisons introduces significant methodological challenges due to the changing composition of the target population and the impact of nonresponse. Section 5.5 discusses these issues in depth and introduces a pseudo-empirical likelihood testing method based on the restricted tests (Aitchison, 1962) approach as well as technical details in the Appendix.

This paper is organised as follows. Section 2 introduces the testing problem of interest and presents examples of bounds on the dominance functions. Section 3 describes the pseudo-empirical likelihood ratio testing procedure and the decision rule. Section 4 introduces the large finite population asymptotic framework, and presents our results. Section 5 discusses the scope of our main results, their implications for empirical practice, and some directions of future research. Section 6 illustrates our testing procedure using HILDA survey data in testing for poverty orderings among Australian households, and Section 7 presents our conclusions.

2 Setup

Panel survey samples on the variable of interest are drawn from units in the first wave of a reference finite population who are also followed over time. The inference procedure of this paper uses data arising from panel surveys between wave 1 and a given subsequent wave. Borne in mind are two finite populations corresponding to the first wave and the subsequent wave of interest. Let 𝒫NK={{YiK,ZiK}:i=1,2,,NK}\mathcal{P}_{N_{K}}=\left\{\{Y^{K}_{i},Z^{K}_{i}\}:i=1,2,\ldots,N_{K}\right\} denote a finite population characterized by the variables (YK,ZK)(Y^{K},Z^{K}) for each K{A,B}K\in\{A,B\}, where NKN_{K} is the population total, YiK𝒳KY^{K}_{i}\in\mathcal{X}_{K}\subset\mathbb{R} is the outcome variable of interest, and ZiKZ^{K}_{i} 0/1 binary variable indicating the unit’s response to the survey in the reference population, for each ii. In the design-based approach (Neyman, 1934), the elements of 𝒫NK\mathcal{P}_{N_{K}} are treated as constant for each K{A,B}K\in\{A,B\}. This approach is different from mainstream statistics and econometrics, and is the core of survey data estimation and inference.

Without loss of generality, let AA correspond to the reference population in wave 1 and BB its subsequent counterpart, so that period AA precedes period BB. In this setup,

the practitioner observesYi={(YiA,YiB)ifZiA=ZiB=1(YiA,)ifZiA=1,ZiB=0,(,)ifZiA=ZiB=0,\displaystyle\text{the practitioner observes}\quad Y_{i}=\ \begin{cases}(Y^{A}_{i},Y^{B}_{i})&\text{if}\ Z^{A}_{i}=Z^{B}_{i}=1\\ (Y^{A}_{i},*)&\text{if}\ Z^{A}_{i}=1,Z^{B}_{i}=0,\\ (*,*)&\text{if}\ Z^{A}_{i}=Z^{B}_{i}=0,\end{cases} (2.1)

where “*” denotes the missing value code, with sampling unit ii from population AA (i.e., in wave 1) and followed through time to population BB (i.e., the subsequent wave). Unit nonresponse corresponds to the event {ZA=ZB=0}\left\{Z^{A}=Z^{B}=0\right\} in our setup since units that do not respond in wave 1 (i.e., population AA) are not followed into later waves (i.e., population BB). Wave nonresponse corresponds to the event {ZA=1,ZB=0}\left\{Z^{A}=1,Z^{B}=0\right\}, since the unit responds in wave 1 but not in the subsequent wave. The event {ZiA=0,ZiB=1}\{Z^{A}_{i}=0,Z^{B}_{i}=1\} does not occur in our setup since units that have not responded to the survey in the first wave are not followed in subsequent waves by design, so that {ZiA=0,ZiB=1}=\{Z^{A}_{i}=0,Z^{B}_{i}=1\}=\emptyset, holds. We do not treat item nonresponse for simplicity and to avoid notational clutter. Its treatment is similar to that of the other kinds of nonresponse and requires the introduction of two more 0/1 binary variables to capture this behavior.

The objective of this paper is to compare the finite population distributions of the outcome variable arising from 𝒫NA\mathcal{P}_{N_{A}} and 𝒫NB\mathcal{P}_{N_{B}} using stochastic dominance under survey nonresponse. For each K{A,B}K\in\{A,B\}, the CDFs of YKY_{K} under 𝒫NK\mathcal{P}_{N_{K}} is defined as FNK(x)=NK1i=1NK𝟙[YiKx]F_{N_{K}}(x)=N_{K}^{-1}\sum_{i=1}^{N_{K}}\mathbbm{1}[Y_{i}^{K}\leq x] for each x𝒳Kx\in\mathcal{X}_{K}. Following Davidson (2008), for K=A,BK=A,B, xx\in\mathbb{R}, define the dominance functions by the recursion: DNK1(x)=FNK(x)D_{N_{K}}^{1}(x)=F_{N_{K}}(x) and DNKs(x)=xDNKs1(u)duD^{s}_{N_{K}}(x)=\int_{-\infty}^{x}D^{s-1}_{N_{K}}(u)\,\text{d}u for s=2,3,4,s=2,3,4,\ldots. Tedious calculation of these integrals yields DNKs(x)=NK1i=1NK(xYiK)s1(s1)!𝟙[YiKx]D^{s}_{N_{K}}(x)=N_{K}^{-1}\sum_{i=1}^{N_{K}}\frac{(x-Y_{i}^{K})^{s-1}}{(s-1)!}\mathbbm{1}[Y_{i}^{K}\leq x] for K{A,B}K\in\{A,B\} and s=1,2,s=1,2,\ldots. We say that FNAF_{N_{A}} stochastically dominates FNBF_{N_{B}} at order ss\in\mathbb{N}, if DNAs(x)DNBs(x)D_{N_{A}}^{s}(x)\leq D_{N_{B}}^{s}(x) x𝒳A𝒳B\forall x\in\mathcal{X}_{A}\cup\mathcal{X}_{B}. We have strict dominance when the inequality is strict over all points in the joint support 𝒳A𝒳B\mathcal{X}_{A}\cup\mathcal{X}_{B}. We make the following assumption on 𝒳A\mathcal{X}_{A} and 𝒳B\mathcal{X}_{B}.

Assumption 1.

𝒳K\mathcal{X}_{K}\subset\mathbb{R} is compact, for K=A,BK=A,B.

This assumption is natural in many applications, for example in the context of income and wealth distributions.

2.1 Hypotheses and Estimating Functions

The test problem of interest in practice is

H0:maxx[t¯,t¯](DNAs(x)DNBs(x))0vs.H1:maxx[t¯,t¯](DNAs(x)DNBs(x))<0,\displaystyle H_{0}:\max_{x\in[\underline{t},\overline{t}]}\left(D_{N_{A}}^{s}(x)-D_{N_{B}}^{s}(x)\right)\geq 0\;\;\text{vs.}\;\;H_{1}:\max_{x\in[\underline{t},\overline{t}]}\left(D_{N_{A}}^{s}(x)-D_{N_{B}}^{s}(x)\right)<0, (2.2)

where [t¯,t¯]interior(𝒳A𝒳B)[\underline{t},\overline{t}]\subseteq\text{interior}\left(\mathcal{X}_{A}\cup\mathcal{X}_{B}\right) and the order ss are pre-designated by the researcher and depends on the context of the application; for example, in poverty analysis using the headcount ratio (i.e., s=1s=1), this interval could be the set of feasible poverty lines. The null hypothesis states that FNAF_{N_{A}} does not stochastically dominate FNBF_{N_{B}} at the ssth order over the interval [t¯,t¯][\underline{t},\overline{t}], and the alternative hypothesis H1H_{1} is its negation; that is, strict restricted stochastic dominance of FNAF_{N_{A}} by FNBF_{N_{B}} at the ssth order.

The natural estimand in developing a statistical procedure for the test problem (2.2) is

{DNAs(x)DNBs(x),x[t¯,t¯]}.\displaystyle\left\{D_{N_{A}}^{s}(x)-D_{N_{B}}^{s}(x),x\in[\underline{t},\overline{t}]\right\}. (2.3)

Using the notion of estimating functions (Godambe and Thompson, 2009), we can define the contrasts (2.3) as the unique solution of census estimating equations, yielding their point-identification. However, nonresponse calls their point-identification into question. In an attempt to circumvent these identification challenges posed by missing data, survey designers have implemented assumptions that nonresponse is ignorable, such as MCAR and Missing at Random (MAR), which point-identify the dominance contrasts (2.3). While such assumptions enable the development of statistical procedures for tackling the testing problem (2.2), they are also typically implausible in practice as nonresponse is not necessarily ignorable.

It is productive to firstly consider the identification of the contrasts (2.3) under nonresponse. Given ss, by the Law of Total Probability, for each xx\in\mathbb{R}

DNKs(x)\displaystyle D_{N_{K}}^{s}(x) =zA,zB{0,1}𝔼FK(|ZA=zA,ZB=zB)[(xYK)s1(s1)! 1[YKx]]δzAzB,\displaystyle=\sum_{z^{A},z^{B}\in\{0,1\}}\mathbbm{E}_{F_{K}\left(\cdot|Z^{A}=z^{A},Z^{B}=z^{B}\right)}\left[\frac{(x-Y^{K})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{K}\leq x\right]\right]\,\delta_{z^{A}z^{B}}, (2.4)

with FK(x|ZA=zA,ZB=zB)=δzAzB1NA1NB1i,j𝟙[YiKx,ZiA=zA,ZjB=zB]F_{K}\left(x|Z^{A}=z^{A},Z^{B}=z^{B}\right)=\delta_{z^{A}z^{B}}^{-1}\,N^{-1}_{A}N^{-1}_{B}\sum_{i,j}\mathbbm{1}\left[Y_{i}^{K}\leq x,Z_{i}^{A}=z^{A},Z^{B}_{j}=z^{B}\right], and δzAzB=NA1NB1i,j𝟙[ZiA=zA,ZjB=zB]\delta_{z^{A}z^{B}}=N_{A}^{-1}N_{B}^{-1}\sum_{i,j}\mathbbm{1}\left[Z^{A}_{i}=z^{A},Z^{B}_{j}=z^{B}\right] whose sums run through the elements of the two finite populations, 𝒫NA\mathcal{P}_{N_{A}} and 𝒫NB\mathcal{P}_{N_{B}}. Since {ZA=0,ZB=1}=\{Z^{A}=0,Z^{B}=1\}=\emptyset, holds, it implies that δ01=0\delta_{01}=0, simplifying the representation of DNKs()D_{N_{K}}^{s}(\cdot) in (2.4) by dropping the conditional expectation 𝔼FK(|ZA=0,ZB=1)[(xYK)s1(s1)! 1[YKx]]\mathbbm{E}_{F_{K}\left(\cdot|Z^{A}=0,Z^{B}=1\right)}\left[\frac{(x-Y^{K})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{K}\leq x\right]\right]. For population K=AK=A, this representation reveals that DNAs()D_{N_{A}}^{s}(\cdot) is not point-identified, since all terms in this representation are identifiable by the data, except for 𝔼FA(|ZA=ZB=0)[(xYK)s1(s1)! 1[YKx]]\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=0\right)}\left[\frac{(x-Y^{K})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{K}\leq x\right]\right]. The same outcome holds for population BB, but now the non-identifiable parts are

𝔼FB(|ZA=1,ZB=0)[(xYB)s1(s1)! 1[YBx]]and𝔼FB(|ZA=ZB=0)[(xYB)s1(s1)! 1[YBx]].\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\;\text{and}\;\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=0\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right].

Consequently, the contrasts (2.3) are not point-identified unless one is willing to make strong assumptions on nonresponse in practice. The most appealing way to mitigate this identification problem created by nonrepsonse is for survey designers to improve the response rates of their surveys and to obtain validation data that delineates the nature of nonresponse. However, in the absence of this, the only way to conduct inference in the test problem (2.2) is by making assumptions that either directly or indirectly constrain the distribution of missing data. Of course, such assumptions are generally nonrefutable as the available data imply no constraints on the missing data. But this approach enables empirical researchers to draw their own conclusions using assumptions they deem credible enough to maintain.

Our approach is to develop a testing procedure based on bounds of the dominance contrasts that depend on observables and encode assumptions on nonresponse. Suppose that the sharp identified set of DNKs()D_{N_{K}}^{s}(\cdot) is given by D¯NKs(x)DNKs(x)D¯NKs(x)\underline{D}_{N_{K}}^{s}(x)\leq D_{N_{K}}^{s}(x)\leq\overline{D}_{N_{K}}^{s}(x) x[t¯,t¯]\forall x\in[\underline{t},\overline{t}] and K=A,BK=A,B, where D¯NKs()\underline{D}_{N_{K}}^{s}(\cdot) and D¯NKs()\overline{D}_{N_{K}}^{s}(\cdot) are the respective lower and upper bounding functions of this set. Then the boundaries of these identified sets imply bounds on the contrasts:

D¯NAs(x)D¯NBs(x)DNAs(x)DNBs(x)D¯NAs(x)D¯NBs(x),x[t¯,t¯].\displaystyle\underline{D}_{N_{A}}^{s}(x)-\overline{D}_{N_{B}}^{s}(x)\leq D_{N_{A}}^{s}(x)-D_{N_{B}}^{s}(x)\leq\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x),\quad\forall x\in[\underline{t},\overline{t}]. (2.5)

The identified set (2.5) captures all the information on the contrasts under the maintained assumption on nonresponse. Now imposing sign restrictions on its bounds is advantageous as it leads to a method of inferring restricted stochastic dominance on the distributions in question. In particular, consider the testing problem:

H01:maxx[t¯,t¯](D¯NAs(x)D¯NBs(x))0vs.H11:maxx[t¯,t¯](D¯NAs(x)D¯NBs(x))<0.\displaystyle H^{1}_{0}:\max_{x\in[\underline{t},\overline{t}]}\left(\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x)\right)\geq 0\;\;\text{vs.}\;\;H^{1}_{1}:\max_{x\in[\underline{t},\overline{t}]}\left(\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x)\right)<0. (2.6)

Rejecting H01H^{1}_{0} in favor of H11H^{1}_{1} in (2.6) implies rejection of H0H_{0} in favor of H1H_{1} in (2.2) since

maxx[t¯,t¯](D¯NAs(x)D¯NBs(x))<0DNAs(x)D¯NAs(x)<D¯NBs(x)DNBs(x),\max_{x\in[\underline{t},\overline{t}]}\left(\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x)\right)<0\implies D^{s}_{N_{A}}(x)\leq\overline{D}_{N_{A}}^{s}(x)<\underline{D}_{N_{B}}^{s}(x)\leq D^{s}_{N_{B}}(x),

holds, x[t¯,t¯]\forall x\in[\underline{t},\overline{t}].

Next, we present a general estimating function approach that targets the contrasts
{D¯NAs(x)D¯NBs(x),x[t¯,t¯]}\left\{\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x),x\in[\underline{t},\overline{t}]\right\}. We also demonstrate this approach’s scope in applications with several important examples. For each x[t¯,t¯]x\in[\underline{t},\overline{t}], consider the estimating function hs(YA,YB,ZA,ZB,θ(x),φ(x))h_{s}\left(Y^{A},Y^{B},Z^{A},Z^{B},\theta(x),\varphi(x)\right), given by

φ3(x)𝟙[ZA=1]θ(x)𝟙[ZA=1](xYB)s1(s1)!𝟙[YBx,ZA=ZB=1]φ4(x)\displaystyle\varphi_{3}(x)\mathbbm{1}\left[Z^{A}=1\right]-\theta(x)\mathbbm{1}\left[Z^{A}=1\right]-\frac{(x-Y^{B})^{s-1}}{(s-1)!}\mathbbm{1}\left[Y^{B}\leq x,Z^{A}=Z^{B}=1\right]\varphi_{4}(x) (2.7)
+(xYA)s1(s1)![𝟙[YAx,ZA=ZB=1]φ1(x)+𝟙[YAx,ZA=1,ZB=0]φ2(x)],\displaystyle+\frac{(x-Y^{A})^{s-1}}{(s-1)!}\left[\mathbbm{1}\left[Y^{A}\leq x,Z^{A}=Z^{B}=1\right]\varphi_{1}(x)+\mathbbm{1}\left[Y^{A}\leq x,Z^{A}=1,Z^{B}=0\right]\varphi_{2}(x)\right],

where φ=[φ1,φ2,φ3,φ4]\varphi=[\varphi_{1},\varphi_{2},\varphi_{3},\varphi_{4}] is a vector of nuisance functionals. For a given vector φNA,NB\varphi_{N_{A},N_{B}}, the estimand in this estimating function is the parameter θ()\theta(\cdot). It solves the census estimating equations

1NA1NBi=1NAj=1NBhs(YiA,YjB,ZiA,ZjB,θ(x),φNA,NB(x))=0x[t¯,t¯].\displaystyle\frac{1}{N_{A}}\frac{1}{N_{B}}\sum_{i=1}^{N_{A}}\sum_{j=1}^{N_{B}}h_{s}\left(Y_{i}^{A},Y_{j}^{B},Z_{i}^{A},Z_{j}^{B},\theta(x),\varphi_{N_{A},N_{B}}(x)\right)=0\quad\forall x\in[\underline{t},\overline{t}]. (2.8)

and has the form

θNA,NB(x;φNA,NB)\displaystyle\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}) =𝔼FA(|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]]δ11δ11+δ10φ1,NA,NB(x)\displaystyle=\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\frac{\delta_{11}}{\delta_{11}+\delta_{10}}\,\varphi_{1,N_{A},N_{B}}(x)
+𝔼FA(|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10δ11+δ10φ2,NA,NB(x)\displaystyle+\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\frac{\delta_{10}}{\delta_{11}+\delta_{10}}\,\varphi_{2,N_{A},N_{B}}(x)
𝔼FB(|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]]δ11δ11+δ10φ4,NA,NB(x)\displaystyle-\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\frac{\delta_{11}}{\delta_{11}+\delta_{10}}\,\varphi_{4,N_{A},N_{B}}(x)
+φ3,NA,NB(x),\displaystyle+\varphi_{3,N_{A},N_{B}}(x),

for each x[t¯,t¯]x\in[\underline{t},\overline{t}]. This estimand targets D¯NAs(x)D¯NBs(x)\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x) under specifications of φNA,NB\varphi_{N_{A},N_{B}} that encode the maintined nonresponse assumptions. The next section illustrates the scope of our approach using several examples.

2.2 Examples

To fix ideas, we introduce examples of sharp bounds that our general formulation covers. We defer a formal analysis to Section D in the Supplementary Material, where we also derive the identified sets of the dominance functions DNAs()D_{N_{A}}^{s}(\cdot) and DNBs()D_{N_{B}}^{s}(\cdot) under the informational assumptions of the examples.

The first example concerns the scenario where there is no information on the nonresponse-generating mechanism available to the practitioner. The worst-case bounds on the contrasts must be used in practice. These bounds summarize what the data, and only the data, say about the dominance contrast (2.3). While they may be wide in practice, it does not necessarily preclude their use for conducting distributional comparisons. Fakih et al. (2022) make this point but in the context of ordinal data and first-order stochastic dominance.

Example 1.

Worst-Case Bounds. Proposition D.1 reports the worst-case identified set of the dominance functions and describes their boundaries. The worst-case bounds on the dominance contrast can be derived using this result. In this scenario, the following specification of φNA,NB\varphi_{N_{A},N_{B}} applies: for each x[t¯,t¯]x\in[\underline{t},\overline{t}],

φ1,NA,NB(x)\displaystyle\varphi_{1,N_{A},N_{B}}(x) =φ4,NA,NB(x)=φ2,NA,NB(x)=δ11+δ10and\displaystyle=\varphi_{4,N_{A},N_{B}}(x)=\varphi_{2,N_{A},N_{B}}(x)=\delta_{11}+\delta_{10}\quad\text{and}
φ3,NA,NB(x)\displaystyle\varphi_{3,N_{A},N_{B}}(x) =(xY¯A)s1(s1)!δ00whereY¯A=inf𝒳A.\displaystyle=\frac{(x-\underline{Y}^{A})^{s-1}}{(s-1)!}\,\delta_{00}\quad\text{where}\quad\underline{Y}^{A}=\inf\mathcal{X}_{A}.

This specification defines θNA,NB(;φNA,NB)=D¯NAs()D¯NBs()\theta_{N_{A},N_{B}}(\cdot;\varphi_{N_{A},N_{B}})=\overline{D}_{N_{A}}^{s}(\cdot)-\underline{D}_{N_{B}}^{s}(\cdot), where for each x[t¯,t¯]x\in[\underline{t},\overline{t}],

D¯NAs(x)\displaystyle\overline{D}_{N_{A}}^{s}(x) =𝔼FA(x|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]]δ11\displaystyle=\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{11}
+𝔼FA(x|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10+(xY¯A)s1(s1)!δ00and\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}+\frac{(x-\underline{Y}^{A})^{s-1}}{(s-1)!}\,\delta_{00}\,\text{and}
D¯NBs(x)\displaystyle\underline{D}_{N_{B}}^{s}(x) =𝔼FB(x|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]]δ11.\displaystyle=\mathbbm{E}_{F_{B}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,\delta_{11}.

Under Assumption 1, these bounds are finite, as Y¯A\underline{Y}^{A}\in\mathbb{R}, holds.

The second example presents bounds that arise from imposing the MCAR assumption on unit nonresponders. While implausible for modeling this type of nonresponse in voluntary surveys, the dominant practice by survey-designers has been to use weights to implement this assumption.

Example 2.

MCAR for Unit Nonresponse. Assuming MCAR for unit nonresponse means

FK(x|ZA=ZB=1)=FK(x|ZA=ZB=0)x𝒳K,\displaystyle F_{K}\left(x|Z^{A}=Z^{B}=1\right)=F_{K}\left(x|Z^{A}=Z^{B}=0\right)\quad\forall x\in\mathcal{X}_{K}, (2.9)

holds, for K=A,BK=A,B. Proposition D.2 reveals that this assumption point-identifies DNAs()D_{N_{A}}^{s}(\cdot) and only partially identifies DNBs()D_{N_{B}}^{s}(\cdot), for each s+s\in\mathbb{Z}_{+}, since FB(x|ZA=1,ZB=0)F_{B}(x|Z^{A}=1,Z^{B}=0) is not pinned down by the conditions (2.9). Thus, in conjunction with the WC lower bound for FB(x|ZA=1,ZB=0)F_{B}(x|Z^{A}=1,Z^{B}=0), the following specification of φNA,NB\varphi_{N_{A},N_{B}} encodes conditions (2.9):

φ1,NA,NB(x)=φ4,NA,NB(x)=(δ11+δ00)(δ11+δ10)δ11,φ2,NA,NB(x)=1,\displaystyle\varphi_{1,N_{A},N_{B}}(x)=\varphi_{4,N_{A},N_{B}}(x)=\frac{(\delta_{11}+\delta_{00})(\delta_{11}+\delta_{10})}{\delta_{11}},\quad\varphi_{2,N_{A},N_{B}}(x)=1,

and φ3,NA,NB(x)=0\varphi_{3,N_{A},N_{B}}(x)=0. This specification defines θNA,NB(;φNA,NB)=D¯NAs()D¯NBs()\theta_{N_{A},N_{B}}(\cdot;\varphi_{N_{A},N_{B}})=\overline{D}_{N_{A}}^{s}(\cdot)-\underline{D}_{N_{B}}^{s}(\cdot), where for each x[t¯,t¯]x\in[\underline{t},\overline{t}],

D¯NAs(x)\displaystyle\overline{D}_{N_{A}}^{s}(x) =𝔼FA(x|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]](δ11+δ00)\displaystyle=\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,(\delta_{11}+\delta_{00})
+𝔼FA(x|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10and\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}\quad\text{and}
D¯NBs(x)\displaystyle\underline{D}_{N_{B}}^{s}(x) =𝔼FB(x|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]](δ11+δ00).\displaystyle=\mathbbm{E}_{F_{B}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,(\delta_{11}+\delta_{00}).

The third example presents bounds that arise from constraining the nonresponse propensities conditional on the outcome, based on ideas in Section 4.2 of Manski (2016). The interesting aspect of this example is that information in the form of shape constraints on Prob(ZA=ZB=0|YKx)\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{K}\leq x\right) for K=A,BK=A,B, and Prob(ZA=1,ZB=0|YBx)\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right) can be incorporated into our inference procedure.

Example 3.

Restrictions on Unit and Wave Nonresponse Propensities. This example constrains the distribution of missing data through bounds on the conditional probabilities Prob(ZA=1,ZB=0|YBx)\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right) and Prob(ZA=ZB=0|YKx)\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{K}\leq x\right) for K=A,BK=A,B. For each x𝒳Ax\in\mathcal{X}_{A}, suppose that

δ00L00A(x)Prob(ZA=ZB=0|YAx)U00A(x)δ00,\delta_{00}\,L^{A}_{00}(x)\leq\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{A}\leq x\right)\leq U^{A}_{00}(x)\,\delta_{00},

where Prob(ZA=ZB=0|YAx)=i,j𝟙[YiAx,ZiA=ZjB=0]i𝟙[YiAx]\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{A}\leq x\right)=\frac{\sum_{i,j}\mathbbm{1}\left[Y_{i}^{A}\leq x,Z_{i}^{A}=Z^{B}_{j}=0\right]}{\sum_{i}\mathbbm{1}\left[Y^{A}_{i}\leq x\right]}, and L00AL^{A}_{00} and U00AU^{A}_{00} are CDFs that are predesignated by the practitioner and satisfy L00AU00AL^{A}_{00}\leq U^{A}_{00}. Bounds on the probability Prob(ZA=ZB=0|YBx)\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{B}\leq x\right) similar to the above also hold, but with CDFs L00BL^{B}_{00} and U00BU^{B}_{00}. Furthermore, consider bounds on the probability Prob(ZA=1,ZB=0|YBx)\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right): for each x𝒳Bx\in\mathcal{X}_{B}, δ10L10(x)Prob(ZA=1,ZB=0|YBx)U10(x)δ10\delta_{10}\,L_{10}(x)\leq\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right)\leq U_{10}(x)\,\delta_{10}, where L10L_{10} and U10U_{10} are CDFs that satisfy L10U10L_{10}\leq U_{10}, and Prob(ZA=1,ZB=0|YBx)=i,j𝟙[YjBx,ZiA=1,ZjB=0]j𝟙[YjBx]\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right)=\frac{\sum_{i,j}\mathbbm{1}\left[Y_{j}^{B}\leq x,Z_{i}^{A}=1,Z^{B}_{j}=0\right]}{\sum_{j}\mathbbm{1}\left[Y^{B}_{j}\leq x\right]}. In practice, shape constraints on the above conditional probabilities can be incorporated into our inference procedure by imposing them on the bounding functions.

Now consider the CDFs given by G¯A(x)=1δ001U00A(x)δ00\overline{G}_{A}(x)=\frac{1-\delta_{00}}{1-U^{A}_{00}(x)\delta_{00}} for each x𝒳Ax\in\mathcal{X}_{A} and G¯B(x)=δ111L00B(x)δ00L10(x)δ10\underline{G}_{B}(x)=\frac{\delta_{11}}{1-L^{B}_{00}(x)\delta_{00}-L_{10}(x)\delta_{10}} for each x𝒳Bx\in\mathcal{X}_{B}. We define their dominance functions recursively: for G{G¯A,G¯B}G\in\{\overline{G}_{A},\underline{G}_{B}\}, these functions are DG1(x)=G(x)D_{G}^{1}(x)=G(x) and DGs(x)=xDGs1(u)duD^{s}_{G}(x)=\int_{-\infty}^{x}D^{s-1}_{G}(u)\,\text{d}u for s=2,3,4,s=2,3,4,\ldots. Furthermore, we define the recursively defined functions on 2\mathbb{R}^{2} given by R0(y,x)=𝟙[yx]R_{0}(y,x)=\mathbbm{1}[y\leq x], Rj(y,x)=xRj1(y,u)𝑑uR_{j}(y,x)=\int_{-\infty}^{x}R_{j-1}(y,u)\,du for j=1,2,j=1,2,\ldots.

Proposition D.3 reports the identified sets of the dominance functions under these informational conditions. Using this result, the specification of θNA,NB(;φNA,NB)=D¯NAs()D¯NBs()\theta_{N_{A},N_{B}}(\cdot;\varphi_{N_{A},N_{B}})=\overline{D}_{N_{A}}^{s}(\cdot)-\underline{D}_{N_{B}}^{s}(\cdot), where for each x[t¯,t¯]x\in[\underline{t},\overline{t}], takes the form

D¯NAs(x)\displaystyle\overline{D}_{N_{A}}^{s}(x) =(δ111δ00FA(x|ZA=ZB=1)+δ101δ00FA(x|ZA=1,ZB=0))DG¯As(x)\displaystyle=\left(\frac{\delta_{11}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=Z^{B}=1\right)+\frac{\delta_{10}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\right)D^{s}_{\overline{G}_{A}}(x)
𝟙[s>1]δ111δ00j=0s2𝔼FA(|ZA=ZB=1)[DG¯As(YA)Rj(YA,x)]\displaystyle\qquad-\mathbbm{1}[s>1]\frac{\delta_{11}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\overline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right]
𝟙[s>1]δ101δ00j=0s2𝔼FA(|ZA=1,ZB=0)[DG¯As(YA)Rj(YA,x)]\displaystyle\qquad-\mathbbm{1}[s>1]\frac{\delta_{10}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{s}_{\overline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right]
D¯NBs(x)\displaystyle\underline{D}_{N_{B}}^{s}(x) =FB(x|ZA=ZB=1)DG¯Bs(x)\displaystyle=F_{B}\left(x|Z^{A}=Z^{B}=1\right)\,D^{s}_{\underline{G}_{B}}(x)
𝟙[s>1]j=0s2𝔼FB(|ZA=ZB=1)[DG¯Bs(YB)Rj(YB,x)].\displaystyle\qquad-\mathbbm{1}[s>1]\sum_{j=0}^{s-2}\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\underline{G}_{B}}(Y^{B})\,R_{j}(Y^{B},x)\right].

Therefore, the following specification of φNA,NB\varphi_{N_{A},N_{B}} encodes this assumption on unit and wave nonrepsonse: for each x[t¯,t¯]x\in[\underline{t},\overline{t}], φ1(x)=φ2(x)=DG¯As(x)\varphi_{1}(x)=\varphi_{2}(x)=D^{s}_{\overline{G}_{A}}(x), φ4(x)=1δ00δ11DG¯Bs(x)\varphi_{4}(x)=\frac{1-\delta_{00}}{\delta_{11}}\,D^{s}_{\underline{G}_{B}}(x), and

φ3(x)\displaystyle\varphi_{3}(x) =𝟙[s>1]j=0s2𝔼FB(|ZA=ZB=1)[DG¯Bs(YB)Rj(YB,x)]\displaystyle=\mathbbm{1}[s>1]\sum_{j=0}^{s-2}\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\underline{G}_{B}}(Y^{B})\,R_{j}(Y^{B},x)\right]
𝟙[s>1]δ111δ00j=0s2𝔼FA(|ZA=ZB=1)[DG¯As(YA)Rj(YA,x)]\displaystyle\qquad-\mathbbm{1}[s>1]\frac{\delta_{11}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\overline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right]
𝟙[s>1]δ101δ00j=0s2𝔼FA(|ZA=1,ZB=0)[DG¯As(YA)Rj(YA,x)].\displaystyle\qquad-\mathbbm{1}[s>1]\frac{\delta_{10}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{s}_{\overline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right].

The fourth example is a neighborhood-based approach to a sensitivity analysis of empirical conclusions to departures from the MCAR assumption for unit and wave nonresponse. It is based on Kline and Santos (2013), who put forward a construction using the maximal Kolmogorov-Smirnov distance between the distributions of missing and observed outcomes, which allows a determination of the critical level of selection for which hypotheses regarding the dominance contrast cannot be rejected.

Example 4.

The MCAR assumption for both unit and wave nonresponse is

FK(x|ZA=ZB=1)\displaystyle F_{K}\left(x|Z^{A}=Z^{B}=1\right) =FK(x|ZA=ZB=0)x𝒳K,K=A,B,and\displaystyle=F_{K}\left(x|Z^{A}=Z^{B}=0\right)\quad\forall x\in\mathcal{X}_{K},K=A,B,\quad\text{and} (2.10)
FB(x|ZA=ZB=1)\displaystyle F_{B}\left(x|Z^{A}=Z^{B}=1\right) =FB(x|ZA=1,ZB=0)x𝒳B.\displaystyle=F_{B}\left(x|Z^{A}=1,Z^{B}=0\right)\quad\forall x\in\mathcal{X}_{B}.

The approach of Kline and Santos (2013) is to build neighborhoods for the non-identified CDFs,
FK(|ZA=ZB=0)F_{K}\left(\cdot|Z^{A}=Z^{B}=0\right) and FB(|ZA=1,ZB=0)F_{B}\left(\cdot|Z^{A}=1,Z^{B}=0\right), according to the maximal Kolmogorov-Smirnov distance to quantify their divergence from the identified CDFs. Proposition D.4 reports the identified sets of the dominance functions DNKs()D_{N_{K}}^{s}(\cdot) under the conditions (D.7). For each K{A,B}K\in\{A,B\}, the boundary of the identified set depends on parameter γA,γB00,γB10[0,1]\gamma_{A},\gamma^{00}_{B},\gamma^{10}_{B}\in[0,1]. The parameters γA\gamma_{A} and γB00\gamma^{00}_{B} represent the fraction in populations AA and BB, respectively, of unit nonresponders whose outcome variable is not well represented by the distribution FA(|ZA=ZB=1)F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right) and FB(|ZA=ZB=1)F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right), respectively. Similarly, the parameter γB10\gamma^{10}_{B} represent the fraction in population BB of wave nonresponders whose outcome variable is not well represented by the distribution FB(|ZA=ZB=1)F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right).

Using this result, we obtain θNA,NB(;φNA,NB)=D¯NAs()D¯NBs()\theta_{N_{A},N_{B}}(\cdot;\varphi_{N_{A},N_{B}})=\overline{D}_{N_{A}}^{s}(\cdot)-\underline{D}_{N_{B}}^{s}(\cdot), where for each x[t¯,t¯]x\in[\underline{t},\overline{t}] and γA,γB[0,1]\gamma_{A},\gamma_{B}\in[0,1]

D¯NAs(x)\displaystyle\overline{D}_{N_{A}}^{s}(x) =𝔼FA(|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]](δ11+(1γA)δ00)\displaystyle=\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,(\delta_{11}+(1-\gamma_{A})\delta_{00})
+𝔼FA(|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10+(xY¯A)s1(s1)!γAδ00and\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}+\frac{(x-\underline{Y}^{A})^{s-1}}{(s-1)!}\,\gamma_{A}\delta_{00}\,\text{and}
D¯NBs(x)\displaystyle\underline{D}_{N_{B}}^{s}(x) =𝔼FB(|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]](δ11+(1γB00)δ00+(1γB10)δ10).\displaystyle=\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,(\delta_{11}+(1-\gamma^{00}_{B})\delta_{00}+(1-\gamma^{10}_{B})\delta_{10}).

Therefore, the following specification of φNA,NB\varphi_{N_{A},N_{B}} encodes this assumption on unit and wave nonrepsonse: for each x[t¯,t¯],x\in[\underline{t},\overline{t}],

φ1(x)\displaystyle\varphi_{1}(x) =(δ11+(1γA)δ00)(δ11+δ10)δ11,φ2(x)=δ11+δ10,\displaystyle=\frac{(\delta_{11}+(1-\gamma_{A})\delta_{00})(\delta_{11}+\delta_{10})}{\delta_{11}},\;\varphi_{2}(x)=\delta_{11}+\delta_{10},
φ3(x)\displaystyle\,\varphi_{3}(x) =(xY¯A)s1(s1)!γAδ00,andφ4(x)=(δ11+(1γB00)δ00+(1γB10)δ10)(δ11+δ10)δ11.\displaystyle=\frac{(x-\underline{Y}^{A})^{s-1}}{(s-1)!}\,\gamma_{A}\delta_{00},\;\;\text{and}\;\;\varphi_{4}(x)=\frac{(\delta_{11}+(1-\gamma^{00}_{B})\delta_{00}+(1-\gamma^{10}_{B})\delta_{10})(\delta_{11}+\delta_{10})}{\delta_{11}}.

2.3 Sample Estimating Equations

In the above examples, the estimating function (2.7) depends only on observables and the nuisance parameter. For a maintained assumption on nonresponse, these examples show that there is a unique value of the nuisance parameter that encodes it into the contrasts {D¯NAs(x)D¯NBs(x),x[t¯,t¯]}\left\{\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x),x\in[\underline{t},\overline{t}]\right\}. We denote this value of the nuisance parameter by φNA,NB\varphi_{N_{A},N_{B}}. It can be consistently estimated using a plug-in procedure with the achieved sample {Yi,iV}\{Y_{i},i\in V\} and the inclusion probabilities πi=Prob[iV]\pi_{i}=\text{Prob}\left[i\in V\right] for iVi\in V, where YiY_{i} is defined in (2.1) for each ii, V{1,,NA}V\subset\{1,\ldots,N_{A}\} is a survey sample of units from population 𝒫A,NA\mathcal{P}_{A,N_{A}} (i.e., wave 1). In practice the inclusion probabilities are reported as design weights, {W,V}\{W_{\ell},\ell\in V\} satisfying the normalization W/k=π1/iVπi1W_{\ell}/k=\pi^{-1}_{\ell}/\sum_{i\in V}\pi^{-1}_{i}, where k=iVk=\sum_{i\in V}.

The estimator of θNA,NB(;φNA,NB)\theta_{N_{A},N_{B}}(\cdot;\varphi_{N_{A},N_{B}}) solves the sample-analogue census estimating equations (2.8):

k1iVWihs(YiA,YiB,ZiA,ZiB,θ(x),φ^(x))=0x[t¯,t¯],k^{-1}\sum_{i\in V}W_{i}\,h_{s}\left(Y_{i}^{A},Y_{i}^{B},Z_{i}^{A},Z_{i}^{B},\theta(x),\hat{\varphi}(x)\right)=0\;\quad\forall x\in[\underline{t},\overline{t}],

where φ^\hat{\varphi} is the plug-in estimator of φNA,NB\varphi_{N_{A},N_{B}}. We can simplify this set of equations using the fact that the moment function hs(YiA,YiB,ZiA,ZiB,θ(x),φ(x))h_{s}\left(Y_{i}^{A},Y_{i}^{B},Z_{i}^{A},Z_{i}^{B},\theta(x),\varphi(x)\right) equals zero for each iVUi\in V-U, where U={iV:ZiA=1}U=\{i\in V:Z_{i}^{A}=1\} is the subsample corresponding to the unit responders, and that

Wik=πi1iVπi1=πi1iUπi1iUπi1iVπi1,\displaystyle\frac{W_{i}}{k}=\frac{\pi^{-1}_{i}}{\sum_{i\in V}\pi^{-1}_{i}}=\frac{\pi^{-1}_{i}}{\sum_{i\in U}\pi^{-1}_{i}}\,\frac{\sum_{i\in U}\pi^{-1}_{i}}{\sum_{i\in V}\pi^{-1}_{i}}, (2.11)

holds. As the ratio iUπi1iVπi1\frac{\sum_{i\in U}\pi^{-1}_{i}}{\sum_{i\in V}\pi^{-1}_{i}} is positive, let {Wi,iU}\{W^{\prime}_{i},i\in U\} be such that

Win=πi1iUπi1iU,wheren=iU.\displaystyle\frac{W^{\prime}_{i}}{n}=\frac{\pi^{-1}_{i}}{\sum_{i\in U}\pi^{-1}_{i}}\quad\forall i\in U,\quad\text{where}\quad n=\sum_{i\in U}. (2.12)

Then, we simplify the sample-analogue of the census estimating equations as
0=iVWikhs(YiA,YiB,ZiA,ZiB,θ(x),φ^(x))=iUWinhs(YiA,YiB,ZiA,ZiB,θ(x),φ^(x))0=\sum_{i\in V}\frac{W_{i}}{k}\,h_{s}\left(Y_{i}^{A},Y_{i}^{B},Z_{i}^{A},Z_{i}^{B},\theta(x),\hat{\varphi}(x)\right)=\sum_{i\in U}\frac{W^{\prime}_{i}}{n}\,h_{s}\left(Y_{i}^{A},Y_{i}^{B},Z_{i}^{A},Z_{i}^{B},\theta(x),\hat{\varphi}(x)\right) for each x[t¯,t¯]x\in[\underline{t},\overline{t}], by substituting out Wi/kW_{i}/k using (2.11) and dividing out the common factor iUπi1iVπi1\frac{\sum_{i\in U}\pi^{-1}_{i}}{\sum_{i\in V}\pi^{-1}_{i}}. The solution of the resulting equation is the sample-analogue estimator

θ^(x;φ^(x))=1niUWiHi(x;φ^(x))x[t¯,t¯],\displaystyle\hat{\theta}(x;\hat{\varphi}(x))=\frac{1}{n}\sum_{i\in U}W^{\prime}_{i}H_{i}(x;\hat{\varphi}(x))\quad\forall x\in[\underline{t},\overline{t}], (2.13)

where for each iUi\in U, Hi(x;φ^(x))H_{i}(x;\hat{\varphi}(x)) is given by

(xYiA)s1(s1)!\displaystyle\frac{(x-Y_{i}^{A})^{s-1}}{(s-1)!} [𝟙[YiAx,ZiA=ZiB=1]φ^1(x)+𝟙[YiAx,ZiA=1,ZiB=0]φ^2(x)]\displaystyle\left[\mathbbm{1}\left[Y_{i}^{A}\leq x,Z_{i}^{A}=Z_{i}^{B}=1\right]\hat{\varphi}_{1}(x)+\mathbbm{1}\left[Y_{i}^{A}\leq x,Z_{i}^{A}=1,Z_{i}^{B}=0\right]\hat{\varphi}_{2}(x)\right] (2.14)
+φ^3(x)𝟙[ZiA=1](xYiB)s1(s1)!𝟙[YiBx,ZiA=ZiB=1]φ^4(x).\displaystyle\qquad+\hat{\varphi}_{3}(x)\mathbbm{1}\left[Z_{i}^{A}=1\right]-\frac{(x-Y_{i}^{B})^{s-1}}{(s-1)!}\mathbbm{1}\left[Y_{i}^{B}\leq x,Z_{i}^{A}=Z_{i}^{B}=1\right]\hat{\varphi}_{4}(x).

3 Testing Procedure

This section introduces the statistical procedure for implementing the hypothesis testing problem (2.6). The procedure is based on the empirical likelihood test of Davidson and Duclos (2013). The test focuses on the boundary of H01H_{0}^{1} in (2.6). For a pair of CDFs FNAF_{N_{A}} and FNBF_{N_{B}} of the outcome variable of interest, the rejection probability will be highest on the subset of the boundary of the null hypothesis H01H_{0}^{1} where we have exactly one x[t¯,t¯]x\in[\underline{t},\overline{t}] such that D¯NAs(x)=D¯NBs(x)\overline{D}_{N_{A}}^{s}(x)=\underline{D}_{N_{B}}^{s}(x). Therefore, we impose the restriction corresponding to the boundary of H01H_{0}^{1} for a single x[t¯,t¯]x\in[\underline{t},\overline{t}]. To maximize the pseudo-empirical likelihood function (PELF) under this restriction, for each x[t¯,t¯]x\in[\underline{t},\overline{t}], compute the maximum PELF whilst imposing D¯NAs(x)=D¯NBs(x)\overline{D}_{N_{A}}^{s}(x)=\underline{D}_{N_{B}}^{s}(x), which is equivalent to θNA,NB(x;φNA,NB(x))=0\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))=0. This corresponds to the maximization problem:

maxp(0,1]niUWilog(pi)\displaystyle\max_{\vec{p}\in(0,1]^{n}}\sum_{i\in U}W^{\prime}_{i}\log(p_{i}) s.t.pi>0i,iUWipi=1,and\displaystyle\text{s.t.}\;\;p_{i}>0\;\forall i,\;\;\sum_{i\in U}W^{\prime}_{i}p_{i}=1,\;\;\text{and} (3.1)
iUWipiHi(x;φ^(x))=0,\displaystyle\sum_{i\in U}W^{\prime}_{i}p_{i}H_{i}(x;\hat{\varphi}(x))=0,

where φ^\hat{\varphi} is a plug-in estimator of φ\varphi, and Hi(x;φ^(x))H_{i}(x;\hat{\varphi}(x)) is the moment function (2.14). The moment condition in (3.1) imposes the restriction D¯NAs(x)=D¯NBs(x)\overline{D}_{N_{A}}^{s}(x)=\underline{D}_{N_{B}}^{s}(x), by tilting the estimator θ^(x;φ^(x))\hat{\theta}(x;\hat{\varphi}(x)) through the probabilities {pi,iU}\{p_{i},i\in U\} on the subsample {Yi,iU}\{Y_{i},i\in U\}.

For a fixed x[t¯,t¯]x\in[\underline{t},\overline{t}] denote by LR(x)L_{R}(x) the maximized value of the constrained maximization problem (3.1). Additionally, let LUR=iUWilog(n1)L_{UR}=\sum_{i\in U}W^{\prime}_{i}\log(n^{-1}), which is the unconstrained maximum value of the PELF which corresponds to (3.1) omitting the constraint iUWipiHi(x;φ^(x))=0\sum_{i\in U}W^{\prime}_{i}p_{i}H_{i}(x;\hat{\varphi}(x))=0. Then the pseudo-empirical likelihood-ratio statistic for the test problem (2.6) is

LR={minx[t¯,t¯]2(LURLR(x))/Deff^(x)ifθ^(x;φ^(x))<0x[t¯,t¯]0,otherwise\displaystyle LR=\begin{cases}\min\limits_{x\in[\underline{t},\overline{t}]}2\left(L_{UR}-L_{R}(x)\right)/\widehat{\text{Deff}}(x)&\text{if}\ \hat{\theta}(x;\hat{\varphi}(x))<0\quad\forall x\in[\underline{t},\overline{t}]\\ 0,&\text{otherwise}\end{cases} (3.2)

where Deff^(x)\widehat{\text{Deff}}(x) is an estimator of the design-effect

Deff(x)=[n1iU(Wi/n)Hi2(x;φ^(x))]1Var(θ^(x;φ^(x))).\displaystyle\text{Deff}(x)=\left[n^{-1}\sum_{i\in U}(W^{\prime}_{i}/n)H^{2}_{i}(x;\hat{\varphi}(x))\right]^{-1}\,Var\left(\hat{\theta}(x;\hat{\varphi}(x))\right). (3.3)

The variance calculation in the numerator of this expression is with respect to the randomness emanating from the survey’s design, so that Deff^()\widehat{\text{Deff}}(\cdot) coincides with Deff()\text{Deff}(\cdot) in (3.3), except that we replace the design-variance Var(θ^(x;φ^(x)))Var\left(\hat{\theta}(x;\hat{\varphi}(x))\right) with a consistent estimator of it. Such estimators are abundant and well-established, and which one to use in practice depends on how much information the practitioner has from the survey designers; e.g., joint selection probabilities enables the use of Taylor linearization, and the availability of replication design weights enables the use of the jackknife (see, for example, Chapter 4 of Fuller, 2009). For each x[t¯,t¯]x\in[\underline{t},\overline{t}], if the moment equality constraint in (3.1) holds in the population, so that θNA,NB(x;φNA,NB(x))=0,\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))=0, then the denominator of Deff(x)\text{Deff}(x), given by iU(Wi/n)Hi2(x)\sum_{i\in U}(W^{\prime}_{i}/n)H^{2}_{i}(x), is the Hájek estimator (Hájek, 1971) of the population variance

SNA,NB(x)=1NA1NBi=1NAj=1NB[hs(YiA,YjB,ZiA,ZjB,0,φNA,NB(x))]2.\displaystyle S_{N_{A},N_{B}}(x)=\frac{1}{N_{A}}\frac{1}{N_{B}}\sum_{i=1}^{N_{A}}\sum_{j=1}^{N_{B}}\left[h_{s}\left(Y_{i}^{A},Y_{j}^{B},Z_{i}^{A},Z_{j}^{B},0,\varphi_{N_{A},N_{B}}(x)\right)\right]^{2}. (3.4)

As the test statistic (3.2) is formulated piece-wise, we only implement the procedure if we observe θ^(x;φ^(x))<0\hat{\theta}(x;\hat{\varphi}(x))<0 for all x[t¯,t¯]x\in[\underline{t},\overline{t}], in the sample. For a fixed nominal level α(0,1)\alpha\in(0,1), the decision rule of the test is to

rejectH01LR>c(α),\displaystyle\text{reject}\ H_{0}^{1}\iff LR>c(\alpha), (3.5)

where c(α)c(\alpha) is be the 1α1-\alpha quantile of the chi-squared distribution with one degree of freedom. The next section presents the asymptotic framework for this testing procedure and establishes its asymptotic properties under the null and alternative hypotheses.

Remark 3.1.

The design-effect arises in the Taylor expansion of LURLR(x)L_{UR}-L_{R}(x) under the null and alternative hypotheses; see Lemmas C.2 and C.3 for results under the null, and see Lemmas C.5 and C.6 for results under the alternative. If we do not account for it as in (3.2), then the testing procedure would suffer from a size distortion under the null, since the distributional limit of the test statistic would be a scaled χ12\chi^{2}_{1}, with scale involving the design variance Var(θ^(x;φ^(x))Var\left(\hat{\theta}(x;\hat{\varphi}(x)\right). Under the alternative, the test would suffer from distortion in type 2 error, and hence, distort its power. Thus, accounting for the survey’s design through the design-effect adjustment in LRLR, corrects these distortions.

4 Asymptotic Framework and Results

Given a sampling scheme for wave 1, denote by 𝒰NA={V:V{1,2,,NA}}\mathcal{U}_{N_{A}}=\{V:V\subset\{1,2,\ldots,N_{A}\}\} the set of all possible samples from the sampling frame {1,2,,NA}\{1,2,\ldots,N_{A}\} according to the survey’s design. Given a sample V𝒰NAV\in\mathcal{U}_{N_{A}}, the survey follows those same sampled units through time to period BB to generate a panel survey between periods AA and BB, yielding the dataset: {(YiA,ZiA),(YiB,ZiB)}iU\left\{(Y_{i}^{A},Z_{i}^{A}),(Y_{i}^{B},Z_{i}^{B})\right\}_{i\in U}. For each K{A,B}K\in\{A,B\}, let NK={𝒫NK:YiK𝒳KandZiK{0,1}fori=1,2,,NK}\mathcal{M}_{N_{K}}=\left\{\mathcal{P}_{N_{K}}:Y^{K}_{i}\in\mathcal{X}_{K}\ \text{and}\ Z^{K}_{i}\in\{0,1\}\ \text{for}\ i=1,2,\ldots,N_{K}\right\}. This set collects all possible finite populations 𝒫NK\mathcal{P}_{N_{K}}. Then the set of all finite populations for both periods AA and BB of sizes NAN_{A} and NBN_{B} is given by:

NA,NB={Π={𝒫NA,𝒫NB}:𝒫NKNK,K=A,B}.\mathcal{M}_{N_{A},N_{B}}=\left\{\Pi=\{\mathcal{P}_{N_{A}},\mathcal{P}_{N_{B}}\}:\mathcal{P}_{N_{K}}\in\mathcal{M}_{N_{K}},\ K=A,B\right\}.

Following Rubin-Bleuer and Kratina (2005), for a fixed finite population ΠNA,NB\Pi_{N_{A},N_{B}} the probability sampling design associated with a sampling scheme on ΠNA,NB\Pi_{N_{A},N_{B}} is the function:

P:σNA×NA,NB[0,1]P:\sigma_{N_{A}}\times\mathcal{M}_{N_{A},N_{B}}\rightarrow[0,1] (4.1)

such that,

  1. (i)

    σNA\sigma_{N_{A}} is a sigma-algebra generated by 𝒰NA\mathcal{U}_{N_{A}};

  2. (ii)

    P(V,)>0is Borel measurable in NA,NB,for allV𝒰NAP(V,\cdot)>0\ \text{is Borel measurable in }\mathcal{M}_{N_{A},N_{B}},\ \text{for all}\ V\in\mathcal{U}_{N_{A}}; and

  3. (iii)

    P(,Π)is a probability measure on 𝒰NA,for allΠNA,NBP(\cdot,\Pi)\ \text{is a probability measure on }\mathcal{U}_{N_{A}},\ \text{for all}\ \Pi\in\mathcal{M}_{N_{A},N_{B}}.

The design probability space is (𝒰NA,σNA,P)(\mathcal{U}_{N_{A}},\sigma_{N_{A}},P) with P(V,)>0P(V,\cdot)>0 for all V𝒰NAV\in\mathcal{U}_{N_{A}} and V𝒰NAP(U,)=1\sum\limits_{V\in\mathcal{U}_{N_{A}}}P(U,\cdot)=1. Under this setup the survey sample size, k=iVk=\sum\limits_{i\in V}, is a random variable and all uncertainty is generated from the probability sampling scheme PP. We follow the notation in finite population literature to indicate that “ΠNA,NB\mid\Pi_{N_{A},N_{B}}" means the sample, {(YiA,ZiA),(YiB,ZiB)}iU\left\{(Y_{i}^{A},Z_{i}^{A}),(Y_{i}^{B},Z_{i}^{B})\right\}_{i\in U}, is drawn from the population ΠNA,NB\Pi_{N_{A},N_{B}}. Therefore, for a fixed ΠNA,NBNA,NB\Pi_{N_{A},N_{B}}\in\mathcal{M}_{N_{A},N_{B}}, 𝔼(ΠNA,NB)\mathbbm{E}(\cdot\mid\Pi_{N_{A},N_{B}}) and Var(ΠNA,NB)Var(\cdot\mid\Pi_{N_{A},N_{B}}) denote the expectation and variance taken over all possible samples from ΠNA,NB\Pi_{N_{A},N_{B}} with respect to the probability space (𝒰NA,σNA,P)(\mathcal{U}_{N_{A}},\sigma_{N_{A}},P). The survey design-weights WiW_{i} satisfy the normalization (2.11), where πi={V𝒰NA:iV}P(V,ΠNA,NB)\pi_{i}=\sum_{\{V\in\mathcal{U}_{N_{A}}\ :\ i\in V\}}P(V,\Pi_{N_{A},N_{B}}) is the inclusion probability of element ii into the sample. The next sections employ this finite population framework to establish the asymptotic properties of the proposed testing procedure in (3.5), as NAN_{A} and NBN_{B} diverge.

4.1 Asymptotic Null Properties

Firstly, we define the set of finite populations that are compatible with the null hypothesis H01H_{0}^{1}. For any NA,NBN_{A},N_{B}\in\mathbb{N} this set is given by

NA,NB0\displaystyle\mathcal{M}_{N_{A},N_{B}}^{0} ={ΠNA,NB:maxx[t¯,t¯]θNA,NB(x;φNA,NB(x))0},\displaystyle=\left\{\Pi\in\mathcal{M}_{N_{A},N_{B}}:\max_{x\in[\underline{t},\overline{t}]}\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))\geq 0\right\},

where θNA,NB(x;φNA,NB(x))=D¯NAs(x)D¯NBs(x)\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))=\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x) for each x[t¯,t¯]x\in[\underline{t},\overline{t}]. Then, the true population, Π0\Pi_{0}, satisfies H01H_{0}^{1} if and only if Π0NA,NB0\Pi_{0}\in\mathcal{M}_{N_{A},N_{B}}^{0}. For any NA,NBN_{A},N_{B}\in\mathbb{N}, the size of the test is given by: supΠNA,NB0𝔼(𝟙[LR>c(α)]Π)\sup_{\Pi\in\mathcal{M}_{N_{A},N_{B}}^{0}}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi\right). For a fixed ΠNA,NB0\Pi\in\mathcal{M}_{N_{A},N_{B}}^{0}, 𝔼(𝟙[LR>c(α)]Π)\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi\right) is the probability of rejecting H01H_{0}^{1} taken over all possible samples from Π\Pi under the probability sampling design (4.1). Therefore, the size of the test is the largest rejection probability over all finite populations in the model NA,NB0\mathcal{M}_{N_{A},N_{B}}^{0}. To approximate the asymptotic size, we embed NA,NB0\mathcal{M}_{N_{A},N_{B}}^{0} into a hypothetical sequence of models {NA,NB0,NA,NB=1,2,}\left\{\mathcal{M}_{N_{A},N_{B}}^{0},\;N_{A},N_{B}=1,2,\ldots\right\} that satisfy enough restrictions so that for a given nominal level α(0,1)\alpha\in(0,1):

lim supNA,NBsupΠNA,NB0𝔼(𝟙[LR>c(α)]Π)α.\limsup_{N_{A},N_{B}\rightarrow\infty}\sup_{\Pi\in\mathcal{M}_{N_{A},N_{B}}^{0}}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi\right)\leq\alpha. (4.2)

The approach to proving (4.2) uses a characterization of it in terms of sequences of finite populations, {ΠNA,NB={𝒫A,NA,𝒫B,NB},NA,NB=1,2,},\left\{\Pi_{N_{A},N_{B}}=\{\mathcal{P}_{A,N_{A}},\mathcal{P}_{B,N_{B}}\},N_{A},N_{B}=1,2,\ldots\right\}, where ΠNA,NBNA,NB0\Pi_{N_{A},N_{B}}\in\mathcal{M}^{0}_{N_{A},N_{B}} for all NAN_{A} and NB,N_{B}, and the asymptotic distribution of {LRΠNA,NB}NA,NB=1+\{LR\mid\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{+\infty} is calculated along this hypothetical infinite sequence. Recall that LRΠNA,NBLR\mid\Pi_{N_{A},N_{B}} means the statistic, LR,LR, is a function of the survey samples selected from population ΠNA,NB\Pi_{N_{A},N_{B}}.

The bounds generated from nonresponse assumptions that we consider are sharp. Under Assumption 1, this sharpness implies φiL([t¯,t¯])\varphi_{i}\in L^{\infty}([\underline{t},\overline{t}]) holds, for each i=1,2,3,4i=1,2,3,4, where L([t¯,t¯])L^{\infty}([\underline{t},\overline{t}]) is the space of uniformly bounded measurable functions from [t¯,t¯][\underline{t},\overline{t}] into \mathbb{R}. The reason is that the worst-case bounds are finite everywhere on [t¯,t¯][\underline{t},\overline{t}] under this assumption (see Example 1), so that φi\varphi_{i} being unbounded on [t¯,t¯][\underline{t},\overline{t}] results in bounds that are not sharp. Let Ψ\Psi denote the vector space of 4-dimensional valued functions, with each component an element of L([t¯,t¯])L^{\infty}([\underline{t},\overline{t}]). For φΨ\varphi\in\Psi, the norm of this space is φΨ=supi=1,2,3,4supx[t¯,t¯]|φi(x)|\|\varphi\|_{\Psi}=\sup_{i=1,2,3,4}\sup_{x\in[\underline{t},\overline{t}]}|\varphi_{i}(x)|.

Next, we describe the conditions on the surveys’ designs for obtaining (4.2). For a given sequence of finite populations {ΠNA,NB}NA,NB=1+,\left\{\Pi_{N_{A},N_{B}}\right\}_{N_{A},N_{B}=1}^{+\infty}, the conditions we impose on the designs of the surveys are given by the following assumption.

Assumption 2.

Fix ss\in\mathbb{N}. For a sequence of finite populations {ΠNA,NB}NA,NB=1\{\Pi_{N_{A},N_{B}}\}_{{N_{A},N_{B}}=1}^{\infty} we impose the following conditions on the survey’s design.

  1. 1.

    𝔼(nΠNA,NB)asNA,NB\mathbbm{E}(n\mid\Pi_{N_{A},N_{B}})\rightarrow\infty\ \text{as}\ N_{A},N_{B}\rightarrow\infty.

  2. 2.

    φ^φNA,NBΨΠNA,NBP0\|\hat{\varphi}-\varphi_{N_{A},N_{B}}\|_{\Psi}\mid\Pi_{N_{A},N_{B}}\operatorname*{\overset{P}{\longrightarrow}}0 as NA,NBN_{A},N_{B}\rightarrow\infty.

  3. 3.

    maxx[t¯,t¯]|θ^(x;φ^(x))θNA,NB(x;φNA,NB(x))|ΠNA,NBP0\max\limits_{x\in[\underline{t},\overline{t}]}\left|\hat{\theta}(x;\hat{\varphi}(x))-\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))\right|\mid\Pi_{N_{A},N_{B}}\operatorname*{\overset{P}{\longrightarrow}}0 as NA,NBN_{A},N_{B}\rightarrow\infty.

  4. 4.

    ForNA,NB=1,2,,Var(θ^(x;φ^(x))ΠNA,NB)>0for eachx[t¯,t¯]\text{For}\ N_{A},N_{B}=1,2,\ldots,\ Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\Pi_{N_{A},N_{B}}\right)>0\ \text{for each}\ x\in[\underline{t},\overline{t}].

  5. 5.

    θ^(;φ^())θNA,NB(;φNA,NB())Var(θ^(;φ^())ΠNA,NB)ΠNA,NB𝔾inL([t¯,t¯])\dfrac{\hat{\theta}(\cdot;\hat{\varphi}(\cdot))-\theta_{N_{A},N_{B}}(\cdot;\varphi_{N_{A},N_{B}}(\cdot))}{\sqrt{Var\left(\hat{\theta}(\cdot;\hat{\varphi}(\cdot))\mid\Pi_{N_{A},N_{B}}\right)}}\mid\Pi_{N_{A},N_{B}}\rightsquigarrow\mathbb{G}\ \text{in}\ L^{\infty}([\underline{t},\overline{t}]) as NA,NBN_{A},N_{B}\rightarrow\infty,

    where \rightsquigarrow denotes weak convergence and 𝔾\mathbb{G} is a zero mean Gaussian process.

  6. 6.

    Var^(θ^(;φ^()))\widehat{Var}\left(\hat{\theta}(\cdot;\hat{\varphi}(\cdot))\right) satisfies maxx[t¯,t¯]|Var(θ^(x;φ^(x)))Var^(θ^(x;φ^(x)))1|ΠNA,NBP0{\displaystyle\max_{x\in[\underline{t},\overline{t}]}\left|\frac{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\right)}{\widehat{Var}\left(\hat{\theta}(x;\hat{\varphi}(x))\right)}-1\right|\mid\Pi_{N_{A},N_{B}}\operatorname*{\overset{P}{\longrightarrow}}0}
    as NA,NBN_{A},N_{B}\rightarrow\infty.

  7. 7.

    The above conditions hold for all subsequences {ΠNAm,NBm}m=1\left\{\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right\}_{m=1}^{\infty} of {ΠNA,NB}NA,NB=1\left\{\Pi_{N_{A},N_{B}}\right\}_{N_{A},N_{B}=1}^{\infty}.

These conditions are versions of commonly used large-sample properties in the survey sampling and partial identification inference literatures; see, for example, Zhao et al. (2020) and Andrews and Soares (2010). Condition 1 imposes the divergence of the mean subsample size of UU as the population totals diverge. Condition 2 imposes the design-consistency of φ^\hat{\varphi} in the norm Ψ\|\cdot\|_{\Psi}. Condition 3 imposes design-consistency of θ^(;φ^)\hat{\theta}(\cdot;\hat{\varphi}), with uniformity over [t¯,t¯][\underline{t},\overline{t}], which can be justified by the preceding condition and the Continuous Mapping Theorem, as the estimand is a linear function of the nuisance parameter. Condition 4 imposes positive design-variance for the statistic θ^(;φ^)\hat{\theta}(\cdot;\hat{\varphi}). Condition 5 requires that a design-based functional central limit theorem holds for the standardized version of θ^(;φ^)\hat{\theta}(\cdot;\hat{\varphi}). Condition 6 imposes design-consistency of the design-variance’s estimator, with uniformity over [t¯,t¯][\underline{t},\overline{t}]. Condition 7 is important for establishing (4.2) via Theorem 1 below.

The embedding sequence of null models for developing (4.2) is made precise in the following definition.

Definition 1.

Suppose that the sequence of null models {NA,NB0,NA,NB=1,2,}\left\{\mathcal{M}_{N_{A},N_{B}}^{0},\;N_{A},N_{B}=1,2,\ldots\right\} is such that every sequence of finite populations {ΠNA,NB}NA,NB=1\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}, with ΠNA,NBNA,NB0\Pi_{N_{A},N_{B}}\in\mathcal{M}_{N_{A},N_{B}}^{0} for each NA,NB=1,2,N_{A},N_{B}=1,2,\ldots, satisfy the conditions of Assumptions 1 and 2. Let 𝕎0\mathbb{W}_{0} denote the set of all such sequences {ΠNA,NB}NA,NB=1\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty} that satisfy Assumption 2.

The first result presents a characterization of (4.2) in terms of {NA,NB0,NA,NB=1,2,}\{\mathcal{M}^{0}_{N_{A},N_{B}},N_{A},N_{B}=1,2,\ldots\} that satisfies Definition 1.

Theorem 1.

Let α(0,1)\alpha\in(0,1) and 𝕎0\mathbb{W}_{0} be as in Definition 1. Then (4.2) is equivalent to

lim supNA,NB𝔼(𝟙[LR>c(α)]ΠNA,NB)α{ΠNA,NB}NA,NB=1𝕎0.\displaystyle\limsup_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi_{N_{A},N_{B}}\right)\leq\alpha\quad\forall\;\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}\in\mathbb{W}_{0}. (4.3)
Proof.

See Appendix B.1. ∎

An important distinction between our framework and the conventional approach in the literature on inference for finite populations is that, like Fakih et al. (2022), we develop the behavior of the test over a set of sequences of finite populations, whereas that literature’s focus has been on a single sequence of that sort (e.g., Wu and Rao, 2006, and Zhao et al., 2020). The result of Theorem 1 shows that this distinction is analogous to the difference between uniform and pointwise asymptotics in the partial identification literature.

The next result establishes the uniform asymptotic validity of the testing procedure, which is essential for reliable inference in large finite populations where the test statistic’s limiting distribution is discontinuous as a function of the underlying population sequence.

Theorem 2.

Let {NA,NB0,NA,NB=1,2,}\left\{\mathcal{M}_{N_{A},N_{B}}^{0},\;N_{A},N_{B}=1,2,\ldots\right\}, 𝕎0\mathbb{W}_{0} and α\alpha be the same as in Theorem 1. Then (4.3) holds.

Proof.

See Appendix B.2. ∎

The key technical steps in the proof of Theorem 2 is to determine the asymptotic distribution of {2(LURLR(x))/Deff^(x)ΠNA,NB}NA,NB=1\{2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\mid\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty} along sequences {ΠNA,NB}NA,NB=1𝕎0\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}\in\mathbb{W}_{0} that drift to/on the boundary of the model of the null hypothesis H01H_{0}^{1} where the rejection probability is highest. We show that the limiting distribution for those sequences is χ12\chi_{1}^{2}. Hence, the test achieves level-α\alpha asymptotically. Consequently, a rejection of H01H^{1}_{0} based on this test using a small significance level constitutes very strong evidence in favor of H11H^{1}_{1}, and hence, is very strong evidence in favor of H1H_{1} defined in (2.2), under the maintained nonresponse assumptions.

4.2 Asymptotic Power Properties

We now develop asymptotic properties of the testing procedure along sequences of finite populations under the alternative hypothesis H11H_{1}^{1}. In a similar vein to the method used to prove the results for asymptotic size, let {NA,NB1,NA,NB=1,2,}\left\{\mathcal{M}_{N_{A},N_{B}}^{1},\ N_{A},N_{B}=1,2,\ldots\right\} be the embedding sequence where

NA,NB1={ΠNA,NB:maxx[t¯,t¯]θNA,NB(x;φNA,NB(x))<0},\mathcal{M}_{N_{A},N_{B}}^{1}=\left\{\Pi\in\mathcal{M}_{N_{A},N_{B}}:\max_{x\in[\underline{t},\overline{t}]}\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))<0\right\},

for each NA,NBN_{A},N_{B}. In this formulation, the true population, Π0\Pi_{0}, satisfies H11H_{1}^{1} if and only if Π0NA,NB1\Pi_{0}\in\mathcal{M}_{N_{A},N_{B}}^{1}. Thus, NA,NB1\mathcal{M}_{N_{A},N_{B}}^{1} corresponds to the model of the alternative hypothesis H11H_{1}^{1}.

For any NA,NBN_{A},N_{B}\in\mathbb{N}, test power is given by 𝔼(𝟙[LR>c(α)]Π0)\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi_{0}\right) when Π0NA,NB1\Pi_{0}\in\mathcal{M}_{N_{A},N_{B}}^{1}. Along a sequence of finite populations {ΠNA,NB}NA,NB=1\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty} under the alternative hypothesis, the asymptotic power is given by

limNA,NB𝔼(𝟙[LR>c(α)]ΠNA,NB).\lim_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi_{N_{A},N_{B}}\right). (4.4)

As α(0,1)\alpha\in(0,1) and c(α)c(\alpha) is a fixed critical value the stochastic behavior the test statistic {LRΠNA,NB}NA,NB\{LR\mid\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}}^{\infty} drives the asymptotic power of the testing procedure. We impose the following conditions on the sequences of finite populations {ΠNA,NB}NA,NB=1\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty} under H11H_{1}^{1}, which are useful for deriving the asymptotic behavior of the test statistic.

Assumption 3.

For a given sequence of finite populations {ΠNA,NB}NA,NB=1\{\Pi_{N_{A},N_{B}}\}_{{N_{A},N_{B}}=1}^{\infty}, we impose the following conditions on the survey’s design:

  1. 1.

    𝔼(nΠNA,NB)nPd++\dfrac{\mathbbm{E}(n\mid\Pi_{N_{A},N_{B}})}{n}\operatorname*{\overset{P}{\longrightarrow}}d\in\mathbb{R}_{++} as NA,NBN_{A},N_{B}\rightarrow\infty.

  2. 2.

    For each x[t¯,t¯]x\in[\underline{t},\overline{t}]:

    1. (i)

      limNA,NBVar(θ^(x;φ^(x))ΠNA,NB)=0\lim\limits_{N_{A},N_{B}\rightarrow\infty}Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\Pi_{N_{A},N_{B}}\right)=0.

    2. (ii)

      limNA,NB𝔼(nΠNA,NB)Var(θ^(x;φ^(x))ΠNA,NB)++\lim\limits_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}(n\mid\Pi_{N_{A},N_{B}})Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\Pi_{N_{A},N_{B}}\right)\in\mathbb{R}_{++}.

    3. (iii)

      limNA,NBSNA,NB(x)++\lim\limits_{N_{A},N_{B}\rightarrow\infty}S_{N_{A},N_{B}}(x)\in\mathbb{R}_{++}, where SNA,NBS_{N_{A},N_{B}} is given by (3.4).

The conditions of Assumption 3 are commonly imposed on the sampling design of surveys (e.g., see Assumption 3 of Wang, 2012). Condition 1 imposes a restriction on the design so that the average sample size and the sample size of {Yi,iU}\{Y_{i},i\in U\} have a similar growth rate with increasing population sizes. On Condition 2, Part (i) imposes diminishing design-variance to zero as the population sizes diverge, Part (ii) pins the rate of decrease of the design-variance in (i) with respect to the average sample size of {Yi,iU}\{Y_{i},i\in U\}. and Part (iii) imposes finite limiting population variance.

Next we describe the embedding of the sequences of finite populations under the alternative hypothesis with respect to which we compute limiting power (4.4).

Definition 2.

Let NA,NB1(ε)={ΠNA,NB:maxx[t¯,t¯]θNA,NB(x;φNA,NB(x))<ε}\mathcal{M}_{N_{A},N_{B}}^{1}(\varepsilon)=\left\{\Pi\in\mathcal{M}_{N_{A},N_{B}}:\max_{x\in[\underline{t},\overline{t}]}\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))<-\varepsilon\right\} for each NA,NBN_{A},N_{B}\in\mathbb{N}, with given ε>0\varepsilon>0. This is the set of finite populations whose dominance contrasts are negative and uniformly bounded away from zero by ε\varepsilon. Let 𝕎1(ε)\mathbb{W}_{1}(\varepsilon) denote the set of all {ΠNA,NB}NA,NB=1\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty} such that ΠNA,NBNA,NB1(ε)\Pi_{N_{A},N_{B}}\in\mathcal{M}_{N_{A},N_{B}}^{1}(\varepsilon) for each NA,NBN_{A},N_{B}\in\mathbb{N}, satisfying Assumptions 1, 2, and 3.

The index set of binding inequalities enters the calculation of the limit (4.4) for the sequences of finite populations in this setup. The following function plays a central role in characterizing the impact of this set on limiting power: for a given sequence of finite populations {ΠNA,NB}NA,NB=1\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}, define the function

C(x)=limNA,NBθNA,NB(x;φNA,NB(x))Var(θ^(x;φ^(x))ΠNA,NB)ΠNA,NBforx[t¯,t¯].C(x)=\lim_{N_{A},N_{B}\rightarrow\infty}\frac{\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\;\Pi_{{N_{A}},{N_{B}}}\right)}}\;\mid\;\Pi_{{N_{A}},{N_{B}}}\quad\text{for}\ x\in[\underline{t},\overline{t}]. (4.5)

We have the following result.

Theorem 3.

Fix α(0,1)\alpha\in(0,1). Let 𝕎1(ε)\mathbb{W}_{1}(\varepsilon) be defined as in Definition 2 and C(x)C(x) be defined as in (4.5). The following statements hold.

  1. 1.

    Fix ε>0\varepsilon>0, then for a sequence of finite populations {ΠNA,NB}NA,NB=1𝕎1(ε)\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}\in\mathbb{W}_{1}(\varepsilon):

    limNA,NB𝔼(𝟙[LR>c(α)]ΠNA,NB)=1.\lim\limits_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi_{N_{A},N_{B}}\right)=1.
  2. 2.

    For a sequence of finite populations {ΠNA,NB}NA,NB=1𝕎1(0)\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}\in\mathbb{W}_{1}(0) define X0={x[t¯,t¯]:C(x)=0}X_{0}=\{x\in[\underline{t},\overline{t}]:C(x)=0\}. If X0X_{0}\neq\emptyset, then

    limNA,NB𝔼(𝟙[LR>c(α)]ΠNA,NB)=Prob[𝔾2(x)>c(α),𝔾(x)<0,xX0].\lim\limits_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi_{N_{A},N_{B}}\right)=\text{Prob}\left[\mathbb{G}^{2}(x)>c(\alpha),\mathbb{G}(x)<0,x\in X_{0}\right].
Proof.

See Appendix B.3. ∎

5 Discussion

This section presents a discussion of the scope of our main results and implications for empirical practice. Section 5.1 discusses the interpretation of H01H^{1}_{0}. Section 5.2 compares the method of this paper with that of Fakih et al. (2022), and Section 5.3 compares and contrasts our method to other tests in the moment inequalities inference literature. Section 5.4 describes the adjustments of our method for inferring that BB dominates AA. Finally, Section 5.5 puts forward an adjustment of calibration to enable pairwise comparisons with waves beyond the first one.

5.1 Interpreting H01H^{1}_{0}

For a given order of stochastic dominance ss\in\mathbb{N} and range [t¯,t¯][\underline{t},\overline{t}], this paper’s statistical procedure aims to infer DNAs(x)<DNBs(x)D_{N_{A}}^{s}(x)<D_{N_{B}}^{s}(x) for all x[t¯,t¯]x\in[\underline{t},\overline{t}] using a paired sample from a panel survey with a maintained assumption on nonresponse. The inference relies on ranking the bounds of these dominance functions, where a rejection event implies DNAs(x)<DNBs(x)D_{N_{A}}^{s}(x)<D_{N_{B}}^{s}(x) throughout the interval [t¯,t¯][\underline{t},\overline{t}] (see testing problem (2.6)). Under the null hypothesis H01H_{0}^{1}, an xx^{*} exists within [t¯,t¯][\underline{t},\overline{t}] where DNAs(x)DNBs(x)D_{N_{A}}^{s}(x^{)}\geq D_{N_{B}}^{s}(x^{*}), a condition that allows DNAs(x)<DNBs(x)D_{N_{A}}^{s}(x)<D_{N_{B}}^{s}(x) elsewhere within the interval. This ambiguity makes H01H_{0}^{1} uninformative due to the partial identification of DNAs()DNBs()D_{N_{A}}^{s}(\cdot)-D_{N_{B}}^{s}(\cdot). Failure to reject this hypothesis yields no definitive conclusions about the populations’ rankings under restricted ssth order stochastic dominance. In such a situation, we recommend empirical researchers perform a sensitivity analysis of this empirical conclusion (i.e., non-rejection of H01H^{1}_{0}) with respect to plausible assumptions on the nonresponse-generating process, using our testing procedure. Additionally, considering higher orders of dominance may be beneficial, especially in poverty and inequality analysis (e.g., Atkinson, 1970, 1987; Foster and Shorrocks, 1988; Deaton, 1997). Section 6 provides an empirical illustration using HILDA survey data.

5.2 Comparison to Fakih et al. (2022)

Fakih et al. (2022) developed a pseudo-empirical likelihood testing procedure for a test problem akin to (1.1), but for, first-order stochastic dominance, ordinal variables, worst-case bounds, and survey data from independent cross-sections. While their procedure is beneficial for such applications, it is narrow in scope. The worst-case bounds can be uninformative in practice, and they do not consider data arising from panel surveys to capture dynamics. Furthermore, the data are discrete and they focus on first-order dominance, which excludes important applications, such poverty and inequality analysis (e.g., Foster and Shorrocks, 1988; Deaton, 1997), collusion detection in industrial organization (Aryal and Gabrielli, 2013), and the ranking of strategies in management sciences (e.g., Harris and Mapp, 1986; Fong, 2010; Minviel and Benoit, 2022). See also Chapter 1 of Whang (2019) and the references therein for other applications of stochastic dominance.

Contrastingly, this paper’s setup is more complex than the setup of Fakih et al. (2022). Paired data from panel surveys possess more complex forms of nonresponse. Unit and item nonresponse can occur within period and wave nonresponse across periods, as well as attrition where sampled units who have previously responded permanently exit the survey. Furthermore, the testing procedure enables the incorporation of prior assumptions on nonresponse, allowing researchers to examine the informational content of their assumptions and their impacts on the inferences made. Another important difference is in the treatment of the design-effect in the statistical procedure. This paper’s procedure employs an estimator of the design-effect as it must be estimated in practice. By contrast, the procedure of Fakih et al. (2022) ignores design-effect estimation as it assumes that it is asymptotically equal to unity with uniformity — see Condition (v) of Assumption 1 in their paper. While they do explain how to adjust their procedure to include an estimator of the design-effect, they do not explicitly account for it in the statements of their results. Reliable estimation of the design-effect becomes more important when considering high order of stochastic dominance, since asymptotically the design-variance would be based on the behaviour of random functions with powers of s1s-1, which could have a profound effect on the testing procedure.

5.3 Comparison to Other Tests

This paper contributes to the vast literature on inference for parameters defined by moment inequalities. While most testing procedures in this literature assume random sampling and test for the opposite of our hypotheses our focus is different. In the context of this paper, those procedures, such as that of Andrews and Shi (2017), apply to the test problems

H0:maxx[t¯,t¯](D¯NAs(x)D¯NBs(x))0vs.H1:maxx[t¯,t¯](D¯NAs(x)D¯NBs(x))>0,\displaystyle H_{0}:\,\max_{x\in[\underline{t},\overline{t}]}\left(\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x)\right)\leq 0\;\;\text{vs.}\;\;H_{1}:\max_{x\in[\underline{t},\overline{t}]}\left(\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x)\right)>0,

but under the random sampling assumption. Unlike typical approaches that infer non-dominance from a null of dominance, we posit a null of non-dominance to infer strict dominance, addressing the methodological challenge where failure to reject the null does not necessarily confirm it, unless test power is high (Davidson and Duclos, 2013, p. 87). This choice reflects our testing objective, which is to infer strict dominance.

Few tests in the moment inequalities literature consider a null of non-dominance, with notable exceptions by Fakih et al. (2022), Davidson and Duclos (2013), and a test proposed by Kaur et al. (1994) based on the minimum tt-statistic for second-order stochastic dominance under complete data and random sampling. Davidson and Duclos (2013) also adapt it for first-order stochastic dominance. Our Supplementary Material’s Lemmas C.2 and C.3 demonstrate that under the null hypothesis H01H_{0}^{1}, the statistic 2(LURLR(x))/Deff^(x)2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x) is asymptotically equivalent to the square of a tt-statistic. Additionally, Lemmas C.5 and C.6 confirm analogous results under local alternatives, establishing the asymptotic local equivalence of our pseudo-empirical likelihood test and the test using the minimum of the squared tt-statistics. Therefore, practitioners can also use the minimum tt-statistic instead of our pseudo-empirical likelihood ratio statistic (3.2) and obtain asymptotically valid tests by comparing it to a quantile from the χ12\chi^{2}_{1} distribution using the same decision rule (3.5).

Moreover, econometricians have also considered design-based approaches to inference for Lorenz dominance but for particular survey designs (e.g., Zheng, 2002; Bhattacharya, 2005, 2007). While Lorenz dominance tests are similar in spirit to various stochastic dominance tests in the literature, their treatment is different as their test statistics are more complicated functionals of the underlying distribution functions. Importantly, these testing procedures have demonstrated that complex sampling designs can greatly affect the estimates of standard errors required for inference. However, they are applicable to complete data, which is their main drawback, as nonresponse is inevitable in socioeconomic surveys.

5.4 Testing BB Dominates AA

In our framework, populations AA and BB represent wave 1 and a subsequent wave, respectively, and interest centers on establishing that AA dominates BB at a predesignated order ss and over a range [t¯,t¯][\underline{t},\overline{t}]. The practitioner may also be interested in establishing that BB dominates AA, which entails considering the testing problem

H0:maxx[t¯,t¯](DNBs(x)DNAs(x))0vs.H1:maxx[t¯,t¯](DNBs(x)DNAs(x))<0.\displaystyle H_{0}:\max_{x\in[\underline{t},\overline{t}]}\left(D_{N_{B}}^{s}(x)-D_{N_{A}}^{s}(x)\right)\geq 0\;\;\text{vs.}\;\;H_{1}:\max_{x\in[\underline{t},\overline{t}]}\left(D_{N_{B}}^{s}(x)-D_{N_{A}}^{s}(x)\right)<0. (5.1)

The framework of Section 2 covers this scenario through specifying φNA,NB\varphi_{N_{A},N_{B}} appropriately to obtain the sharp upper bound D¯NBs()D¯NAs()\overline{D}^{s}_{N_{B}}(\cdot)-\underline{D}^{s}_{N_{A}}(\cdot) on the contrast DNBs()DNAs()D_{N_{B}}^{s}(\cdot)-D_{N_{A}}^{s}(\cdot), so that estimation and testing can proceed as described above.

We repeat the same examples as in Section 2.2 but for the testing problem (5.1), and relegate those details to Appendix E.1 for brevity. The technical derivations of the bounds in each example follow steps similar to the ones in the examples of Section 2.2. The general idea with this set of examples is to carefully specify φNA,NB\varphi_{N_{A},N_{B}} to obtain the desired form of θNA,NB()=D¯NBs()D¯NAs()\theta_{N_{A},N_{B}}(\cdot)=\overline{D}^{s}_{N_{B}}(\cdot)-\underline{D}^{s}_{N_{A}}(\cdot).

5.5 Comparisons of Two Waves Beyond Wave 1

This section presents a discussion of how to carry out inference for stochastic dominance with two populations beyond the first wave within our framework. Firstly, it points to a limitation of a leading practice in the literature called calibration that has been used to address nonresponse. Second, it proposes a bounds approach to inference for stochastic dominance based on restricted tests (Aitchison, 1962). This approach combines the basic idea of calibration with the framework of the previous sections in the paper.

A longitudinal weight between these waves must be utilized instead of the design weights to compare populations of two subsequent waves beyond the first. The idea behind longitudinal weights is to reflect the finite population at the initial wave of the comparison by accounting for the dynamic nature of the panel, where the achieved sample in wave 1 evolves with time due to following rules and population changes. The process of calibration estimation obtains such weights. The seminal paper of Deville and Sarndal (1992) formalized the general concept and techniques of calibration estimation in the context of survey sampling with complete data to improve estimators’ efficiency and ensure coherency with population information. The idea of using extra information to enhance inference has a long tradition in statistics and econometrics; see, for example,  Aitchison (1962); Imbens and Lancaster (1994); Parente and Smith (2017).

The calibration estimator uses calibrated weights, which are as close as possible, according to a given distance measure, to the original sampling design weights while also respecting a set of constraints, which represent known auxiliary population benchmarks/information, to ensure the resulting weighted estimates match (typically external) high-quality totals or means of the initial wave in the comparison.111See Wu and Lu (2016) for examples of distance measures used in calibration. This method is ideal for incorporating such information in the setup with complete responses and a representative sample of the target population.

Calibration is also widely applied under nonresponse, but with the achieved sample of responding units – a procedure that is known as weighting (see Chapter 5 of Sarndal and Lundstrom, 2005). Under nonresponse, weighting thus relies on the assumption that the supports of the outcome variable conditional on response and nonresponse coincide. While suitable for specific empirical applications, this assumption can be untenable in other applications. It is implausible when there are reasons to expect that the missing units tend to belong to a subpopulation of the target population. For example, a widely shared view of household surveys is that the missing incomes correspond to households at the top of the income distribution (e.g., Lustig, 2017; Bourguignon, 2018). The issue is that the achieved sample on the outcome variable (i.e., of responding units) in the first wave is biased because it represents a subpopulation of the target population. Following the units of this sample over time could perpetuate their selectivity bias in subsequent waves, where the known auxiliary population benchmarks/information in the subsequent waves may not be compatible with the subpopulation that the achieved sample represents. Consequently, calibrating design weights using the achieved (biased) sample can result in misleading inferences.

The challenge with calibration in our missing data setup is that the achieved sample is generally not representative of the target population. The achieved sample could represent a subpopulation of the target population, which may not satisfy the auxiliary information. If there are known auxiliary benchmarks/information on that subpopulation, then the design weights can be calibrated using this sample and auxiliary benchmarks/information. This calibration approach can be combined with our bounds approach of the previous sections to develop a statistical procedure for inference on stochastic dominance for the target populations under nonresponse. The known auxiliary benchmarks/information on the subpopulations may be derived from or implied by their counterparts on the target population in the form of subpopulation totals or means, for instance.

More concretely, AA now represents the population of the initial wave in the comparison and BB now represents the later wave. The subpopulation 𝒫NA1={{YiA,ZiA}𝒫NA:ZiW1=1},\mathcal{P}_{N_{A_{1}}}=\left\{\{Y^{A}_{i},Z^{A}_{i}\}\in\mathcal{P}_{N_{A}}:Z_{i}^{W_{1}}=1\right\}, is the one the sample represents, where ZiW1Z_{i}^{W_{1}} is the 0/1 binary variable indicating on response in the population corresponding to the first wave of the survey. Let {Gi:i=1,,NA1}\{G_{i}:i=1,\ldots,N_{A_{1}}\} where GiG_{i}\in\mathbb{R} be the population value of the auxiliary variable for each ii, and NA1N_{A_{1}} is the subpopulation total. The information we have is the constraint 1NA1i=1NA1Gi=G0\frac{1}{N_{A_{1}}}\sum_{i=1}^{N_{A_{1}}}G_{i}=G_{0}, but because of nonresponse, the data on this auxiliary variable will have missing values, which would be the units {iU:ZiA1=0}\{i\in U:Z^{A_{1}}_{i}=0\}. If there are known bounds on GiG_{i}, i.e., G¯GiG¯\underline{G}\leq G_{i}\leq\overline{G} for all ii in the subpopulation A1A_{1}, then using the aforementioned bounds, the following inequality restrictions must hold

1NA1(i=1:ZiA1=1NA1Gi+i=1:ZiA1=0NA1G¯)G0and1NA1(i=1:ZiA1=1NA1Gi+i=1:ZiA1=0NA1G¯)G0.\displaystyle\frac{1}{N_{A_{1}}}\left(\sum_{i=1:Z^{A_{1}}_{i}=1}^{N_{A_{1}}}G_{i}+\sum_{i=1:Z^{A_{1}}_{i}=0}^{N_{A_{1}}}\overline{G}\right)\geq G_{0}\,\text{and}\,\frac{1}{N_{A_{1}}}\left(\sum_{i=1:Z^{A_{1}}_{i}=1}^{N_{A_{1}}}G_{i}+\sum_{i=1:Z^{A_{1}}_{i}=0}^{N_{A_{1}}}\underline{G}\right)\leq G_{0}. (5.2)

Employing the information (5.2) in testing entails the consideration of the restricted testing problem:

H02:\displaystyle H_{0}^{2}: maxx[t¯,t¯](D¯NAs(x)D¯NBs(x))0,and(5.2)versus\displaystyle\max_{x\in[\underline{t},\overline{t}]}\left(\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x)\right)\geq 0,~\text{and}~(\ref{eq - WC bounds Aux})\quad\text{versus} (5.3)
H12:\displaystyle H^{2}_{1}: maxx[t¯,t¯](D¯NAs(x)D¯NBs(x))<0and(5.2),\displaystyle\max_{x\in[\underline{t},\overline{t}]}\left(\overline{D}_{N_{A}}^{s}(x)-\underline{D}_{N_{B}}^{s}(x)\right)<0\,~\text{and}~(\ref{eq - WC bounds Aux}),

where the bounds, D¯NAs\overline{D}_{N_{A}}^{s} and D¯NBs\underline{D}_{N_{B}}^{s}, account for nonresponse through the use of side information or a maintained assumption on nonresponse.

A testing procedure using the method of pseudo-empirical likelihood is feasible since it can implement the information (5.2) as additional constraints in formulating the pseudo-empirical likelihood-ratio statistic. These constraints are imposed under both the null and alternative hypotheses for internal consistency (Wu and Lu, 2016), so that the transformed design weights are compatible with subpopulation A1A_{1}. We conjecture the asymptotic form of the test statistic is equivalent to generalized likelihood ratio statistic for a cone-based testing problem on a multivariate normal mean vector (e.g., Theorem 3.4 of Raubertas et al., 1986). There are challenges with implementing the testing procedure, as the subset of inequalities in (5.2) that are active/binding enters the design effect; see Appendix E.2 for the details. This set is unknown and difficult to estimate reliably, which can profoundly impact the overall reliability of the testing procedure. It renders the distribution as non-pivotal, which creates challenges for calculation of its quantiles. One possible avenue forward is to adapt the bootstrap procedure of Wang et al. (2022) to the setup of inequality restrictions in order circumvent this computational difficulty – we leave it for future research.

6 Empirical Application

The empirical analysis aims to investigate the temporal orderings of poverty among Australian households using data from the HILDA panel survey. This survey’s design, described in detail by Watson and Wooden (2002), is complex, involving multiple stages, clustering, stratification, and unequal probability sampling. The unit of observation is the household, which means that each household contributes one data point to the dataset. We use equivalized household net income (EHNI) based on the OECD’s equivalence scale as the measure of material resources available to a household .222This scale assigns a value of 1 to the first household member, of 0.7 to each additional adult and of 0.5 to each child. The equivalization adjustments of households’ net incomes are essential for meaningful comparisons between different types of households, as it accounts for variations in household size and composition and considering the economies of scale that arise from sharing dwellings.

The HILDA panel survey has been conducted annually since 2001 and provides reports that present selected empirical findings on Australian households and individuals across the survey waves. A recent issue, Wilkins et al. (2022), indicates an upward trend in the median and average EHNI. This suggests a steady decline in household poverty between 2001 and 2022, as shown in Figures 3.1 and 3.2 of their report. However, this empirical evidence is rather weak and potentially misleading as it does not consider (i) household poverty lines, which concerns the lower tails of the EHNI distributions, and (ii) a poverty index.

Our empirical analysis utilizes restricted stochastic dominance (RSD) orderings to effectively rank distributions of households’EHNI in terms of poverty. The concept of poverty orderings based on RSD conditions was introduced by Foster and Shorrocks (1988) to provide robust comparisons of poverty. This approach overcomes the challenge of defining a single poverty line to identify and categorize households as poor. Instead, it compares distributions across a range of poverty lines. In this context, the range of poverty lines corresponds to different levels of EHNI for various types of households. A household is considered to be in poverty if its EHNI falls below its corresponding poverty line. By employing RSD orderings and considering multiple poverty lines, our analysis offers a more comprehensive and nuanced understanding of poverty and avoids the limitations of relying on a single threshold to define poverty.

The robust comparison of households’ EHNI distributions using the HILDA survey data is complicated by the presence of nonresponse, because the distributions are only partially identified. In producing their annual reports, the survey designers have implemented the following assumptions on nonresponse. They address unit nonresponse through re-weighting responding households by distributing the weight of nonresponding households to other like responding households, assuming nonrespondents are the same as respondents. In other words, they implement the MCAR assumption for unit nonresponse – see Watson and Fry (2002) for more details. Furthermore, they address wave and item nonresponse through imputation.

The assumptions made by the survey designers on nonresponse, specifically unit and wave nonresponse, are implausible in practice. There is descriptive empirical evidence showing nonresponse rates tend to be highest at both ends of the income distribution. For example, logistic regression analyses demonstrate a U-shaped relationship between unit nonresponse and median weekly household incomes (see Table A3.1 in Watson and Fry, 2002) and wave nonresponse is also U-shaped with respect to individual EHNI (see Table 10.2 in Watson and Wooden, 2009). However, the imputation of missing household incomes in the case of item nonresponse is considered reliable due to the availability of comprehensive information on partially responding households’ characteristics and the income components of responding individuals. This additional information allows for reasonably accurate imputations – see Watson and Wooden (2004) for an example of their imputation method for missing income data in wave 2.

The empirical analysis focuses on the first four waves, and uses the forgoing evidence on nonresponse to establish bounds on dominance contrasts, which are then implemented in our statistical procedure. The rest of this section is organized as follows. Section 6.1 describes the dataset and Section 6.2 presents our results with a discussion.

6.1 Description of Dataset

We have focused on pairwise comparisons between the first wave and waves 2, 3, and 4. In the notation introduced earlier, AA represents the population of Australian households in 2001, which corresponds to wave 1. BB would then represent either of the population of Australian households in the years 2002, 2003, and 2004, corresponding to waves 2, 3, and 4, respectively.

In the first wave of the HILDA survey, there were 12252 addresses issued which resulted in 804 addresses being identified as out of scope (as they were vacant, non-residential, or all members of the household were not living in Australia for 6 months or more). In addition, there were 245 households added to the sample due to multiple households living at one address. This resulted in 1169311693 in-scope households of which 7682 responded. These responding households are followed through time.

Households can grow, split, and dissolve over time, which creates unbalanced panels. As the split households’s were followed, to form a balanced panel, we double counted the split households, but equally distributed their design weights. For example, between waves 1 and 2, 712 of (responding) households in wave 1 split. This approach yields a balanced panel with n=7682+712=8395n=7682+712=8395 unit responding households a from a sample size of k=11693+712=12405k=11693+712=12405. Table 1 reports the values of kk and nn for all of the wave pairs based on this construction of the balanced panel. There are other balancing approaches and we do not take a stand on which one to favour; see, for example, the "fare shares approach" described in Taylor (2010) for a different re-balancing method.

Now we provide details on estimation of the fractions δ00\delta_{00}, δ10\delta_{10}, and δ11\delta_{11}. A standard approach uses the survey design weights {ωi:iV}\{\omega_{i}:i\in V\} in their estimation. However, the HILDA survey does not provide the subset of those weights corresponding to unit nonresponding households. This means the practitioner only has access to {ωi:iU}\{\omega_{i}:i\in U\} and not {ωi:iVU}\{\omega_{i}:i\in V-U\}. Furthermore, the survey team has scaled the provided weights so that iUωi=NA\sum_{i\in U}\omega_{i}=N_{A}, where NA=7404297N_{A}=7404297 is the total number of Australian households in 2001. Despite this setup, we can still estimate δ00\delta_{00}, δ10\delta_{10}, and δ11\delta_{11} as follows. Estimate δ00\delta_{00} as δ^00=(kn)/k\hat{\delta}_{00}=(k-n)/k, which is an unweighted estimator of δ00\delta_{00} on account of not having the complete set of weights. Since the provided weights satisfy iUωi=NA\sum_{i\in U}\omega_{i}=N_{A}, we re-scale them so that the resulting weights {ωi:iU}\{\omega^{\prime}_{i}:i\in U\} sum to (n/k)NA(n/k)N_{A}. Then we estimate δ10\delta_{10} and δ11\delta_{11} as δ^10=NA1iU:ZB=0ωi\hat{\delta}_{10}=N^{-1}_{A}\sum_{i\in U:Z^{B}=0}\omega^{\prime}_{i} and δ^11=1δ^10δ^00\hat{\delta}_{11}=1-\hat{\delta}_{10}-\hat{\delta}_{00}, respectively. Table 1 reports the estimates of these fractions for all wave pairs.

Table 1: Preliminary Calculations

Population kk nn δ^00\hat{\delta}_{00} δ^10\hat{\delta}_{10} δ^11\hat{\delta}_{11} [t¯,t¯][\underline{t},\overline{t}] Deflation Factor
Waves 1 and 2 12405 8395 0.3233 0.0855 0.5912 [6917.01,14872][6917.01,14872] 1.03
Waves 1 and 3 12876 8865 0.3115 0.1275 0.561 [6622,14872][6622,14872] 1.06
Waves 1 and 4 13255 9244 0.3026 0.1601 0.5373 [6917.01,15262][6917.01,15262] 1.08
Refer to caption
Figure 2: Figures report bounds on DNA1D^{1}_{N_{A}} and DNB1D^{1}_{N_{B}} over the range of poverty lines under two sets of assumptions on nonresponse. The left figure reports the worst-case bounds. The right figure reports the bounds under the MCAR assumption on unit nonresponse and worst-case scenario on wave nonresponse.

The weights {Wi,iU}\{W^{\prime}_{i},i\in U\} we use in the statistical procedure and in the derivation of our results are obtained by re-scaling {ωi:iU}\{\omega^{\prime}_{i}:i\in U\} so that they sum to nn. The range of poverty lines we consider are reported in Table 1, all denominated in 2001 AUD using the deflation factors obtained from the Reserve Bank of Australia’s inflation calculator.333The inflation calculator’s URL is https://www.rba.gov.au/calculator/. The poverty line ranges are based on the tables reported in Wilkins (2001, 2002, 2003, 2004) after equivalizing them according to the OECD equivalence scale.

We do not expect the EHNI population distribution to change rapidly across the first 4 waves. We encode this restriction by setting 𝒳A=𝒳B\mathcal{X}_{A}=\mathcal{X}_{B} for B{wave 2, wave 3, wave 4}B\in\{\text{wave 2, wave 3, wave 4}\}. Furthermore, we have set 𝒳A=𝒳B=[150000,1000000]\mathcal{X}_{A}=\mathcal{X}_{B}=[-150000,1000000], where the upper and lower bounds are larger and smaller, respectively, than the observed values, because of the high incidence of unit nonresponse. Of course, this assumption is irrefutable; however, it is credible since there is evidence from logistic regression analyses reported in Table A3.1 of Watson and Fry (2002) demonstrating a U-shaped relationship between unit nonresponse and median weekly household incomes of different neighborhoods. In consequence, the EHNI of unit nonresponders is likely to be in the tails of the EHNI population distribution. In practice, one can also study the sensitivity of outcomes based on it.

Figure 2 reports estimates of the bounds on the dominance functions DNA1D^{1}_{N_{A}} and DNB1D^{1}_{N_{B}} under two sets of assumptions on nonresponse for each pair of waves in our study. The left figure depicts their worst-case bounds. These bounds summarize what the data, and only the data, say about DNA1D^{1}_{N_{A}} and DNB1D^{1}_{N_{B}}. They are instructive since it establishes “a domain of consensus among researchers who may hold disparate beliefs about what assumptions are appropriate” (Horowitz and Manski, 2006). However, they are not informative in our setup because we find the identified set of DNA1D^{1}_{N_{A}} is a proper subset of its DNB1D^{1}_{N_{B}} counterpart for each pair of waves. The right panels of the figure depict the bounds under the MCAR assumption on unit nonresponse without any assumption on wave nonresponse. The HILDA survey implements this assumption on unit nonresponse in its data releases. It is a very strong assumption that point-identifies DNA1D^{1}_{N_{A}}. Without any assumptions on wave nonresponse, DNB1D^{1}_{N_{B}} is only partially identified. As with the worst-case bounds, these bounds are also not informative because the point estimate of DNA1D^{1}_{N_{A}} is an element of DNB1D^{1}_{N_{B}}’s identified set, for each pair of waves.

Finally, to approximate the design effect (3.3), we have used the jackknife and the replication design weights (provided by the survey’s release). See Hayes (2008) for a general description of this procedure to calculate standard errors of estimators using HILDA survey data.

6.2 Results

We would like to evaluate the dynamics of poverty between waves 1 and 2, waves 1 and 3, and waves 1 and 4, using the headcount ratio for each poverty line in their respective range [t¯,t¯][\underline{t},\overline{t}]. Therefore, the testing problem of interest is given by (5.1) with s=1s=1; that is

H0:maxx[t¯,t¯](D¯NB1(x)D¯NA1(x))0vs.H1:maxx[t¯,t¯](D¯NB1(x)D¯NA1(x))<0.\displaystyle H_{0}:\max_{x\in[\underline{t},\overline{t}]}\left(\overline{D}_{N_{B}}^{1}(x)-\underline{D}_{N_{A}}^{1}(x)\right)\geq 0\;\;\text{vs.}\;\;H_{1}:\max_{x\in[\underline{t},\overline{t}]}\left(\overline{D}_{N_{B}}^{1}(x)-\underline{D}_{N_{A}}^{1}(x)\right)<0. (6.1)

This section reports the results of a sensitivity analysis of the event “Reject H0H_{0}” in the forgoing test problem for each pair of waves at the 5% significance level, using nonresponse assumptions based on Examples 3 and 4, which present alternative perspectives on how missing data differ from observed outcomes. In those examples, the focus was on the contrast xDNA1(x)DNB1(x)x\mapsto D^{1}_{N_{A}}(x)-D^{1}_{N_{B}}(x), and in this testing problem, we must consider the contrast xDNB1(x)DNA1(x)x\mapsto D^{1}_{N_{B}}(x)-D^{1}_{N_{A}}(x) instead. Using the results of Propositions D.3 and D.4, which report the forms of D¯NB1\overline{D}_{N_{B}}^{1} and D¯NA1\underline{D}_{N_{A}}^{1} for these two types of neighborhood assumptions, we can derive the corresponding identified sets of the contrast of interest.

6.2.1 Neighborhood of MCAR: Kolmogorov-Smirnov Distance

The result of Proposition D.4 delivers the forms of D¯NB1\overline{D}_{N_{B}}^{1} and D¯NA1\underline{D}_{N_{A}}^{1}. In particular, for each x[t¯,t¯]x\in[\underline{t},\overline{t}] and γA,γB00,γB10[0,1]\gamma_{A},\gamma^{00}_{B},\gamma^{10}_{B}\in[0,1], the dominance functions are given byD¯NA1(x)=FA(x|ZA=ZB=1)(δ11+(1γA)δ00)+FA(x|ZA=1,ZB=0)δ10\underline{D}_{N_{A}}^{1}(x)=F_{A}\left(x|Z^{A}=Z^{B}=1\right)\,(\delta_{11}+(1-\gamma_{A})\delta_{00})+F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\,\delta_{10} and D¯NB1(x)=FB(x|ZA=ZB=1)(δ11+(1γB00)δ00+(1γB10)δ10)+(γB00δ00+γB10δ10)\overline{D}_{N_{B}}^{1}(x)=F_{B}\left(x|Z^{A}=Z^{B}=1\right)\,(\delta_{11}+(1-\gamma^{00}_{B})\delta_{00}+(1-\gamma^{10}_{B})\delta_{10})+(\gamma^{00}_{B}\delta_{00}+\gamma^{10}_{B}\delta_{10}).

Next, we report results of the sensitivity analysis of the event “Reject H0H_{0}” in the test problem (6.1) for each pair of waves, with respect all values of the triple (γA,γB00,γB10)(\gamma_{A},\gamma^{00}_{B},\gamma^{10}_{B}) in the 3-dimensional grid Ξ={0,0.1,0,2,,0.9,1}3\Xi=\{0,0.1,0,2,\ldots,0.9,1\}^{3}. Let Ξ1,j\Xi^{1,j} denote the subset of Ξ\Xi where this rejection of the null occurs for the waive pairs 11 and jj, for j=2,3,4j=2,3,4. Interestingly, we did not find considerable deviations from the MCAR assumptions at the 5% significance level, as the tests did not reject this null hypothesis for the majority of points in Ξ\Xi for each pair of waves. Specifically, we have obtained Ξ1,2=Ξ1,3={(0,0,0),(0.1,0,0)}\Xi^{1,2}=\Xi^{1,3}=\left\{(0,0,0),(0.1,0,0)\right\} and Ξ1,4={(0,0,0),(0.1,0,0),(0.2,0,0),(0.3,0,0)}\Xi^{1,4}=\left\{(0,0,0),(0.1,0,0),(0.2,0,0),(0.3,0,0)\right\}, where the MCAR assumption arises under the parameter specification (γA,γB00,γB10)=(0,0,0)(\gamma_{A},\gamma^{00}_{B},\gamma^{10}_{B})=(0,0,0). The implication is that the decline in poverty over time is not robust to deviations from the MCAR assumption with respect to the Kolmogorov-Smirnov distances between FK(|ZA=ZB=1)F_{K}\left(\cdot|Z^{A}=Z^{B}=1\right) and FK(|ZA=ZB=0)F_{K}\left(\cdot|Z^{A}=Z^{B}=0\right) for K=A,BK=A,B, and between FB(|ZA=ZB=1)F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right) and FB(|ZA=1,ZB=0)F_{B}\left(\cdot|Z^{A}=1,Z^{B}=0\right).

The non-rejections arise because H0H_{0} in (6.1) occurs in the sample, forcing the test statistic to equal zero. Therefore, we cannot conclude anything informative about the ranking of the two EHNI distributions using first-order restricted stochastic dominance, for (γA,γB00,γB10)(\gamma_{A},\gamma^{00}_{B},\gamma^{10}_{B}) in ΞΞ1,j\Xi-\Xi^{1,j} and j=2,3,4j=2,3,4. Hence, we have also considered sensitivity with respect to the poverty index by testing using second-order restricted dominance (i.e., s=2s=2) and the values of (γA,γB00,γB10)(\gamma_{A},\gamma^{00}_{B},\gamma^{10}_{B}) in ΞΞ1,j\Xi-\Xi^{1,j} for j=2,3,4j=2,3,4. Ranking EHNI distributions using second-order restricted dominance corresponds to ranking them robustly according to the per capita income gap poverty index. Using the same significance level, the tests did not reject this null hypothesis for the majority of points in ΞΞ1,j\Xi-\Xi^{1,j} and j=2,3,4j=2,3,4. Let Ξ21,jΞΞ1,j\Xi^{1,j}_{2}\subset\Xi-\Xi^{1,j} be the set where this rejection of the null occurs for the waive pairs 11 and jj, for j=2,3,3,4j=2,3,3,4. They are given by Ξ21,2=Ξ21,2={(0.2,0,0),(0.3,0,0)}\Xi^{1,2}_{2}=\Xi^{1,2}_{2}=\left\{(0.2,0,0),(0.3,0,0)\right\} and Ξ21,4={(γA,0,0):γA=0.4,0.5,0.6,0.7}\Xi^{1,4}_{2}=\left\{(\gamma_{A},0,0):\gamma_{A}=0.4,0.5,0.6,0.7\right\}. The situation is similar to the case of first-order restricted dominance above: the decline in poverty over time, now with respect to per capita income gap, is not robust to deviations from the MCAR assumption with respect to the Kolmogorov-Smirnov distances between FK(|ZA=ZB=1)F_{K}\left(\cdot|Z^{A}=Z^{B}=1\right) and FK(|ZA=ZB=0)F_{K}\left(\cdot|Z^{A}=Z^{B}=0\right) for K=A,BK=A,B, and between FB(|ZA=ZB=1)F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right) and FB(|ZA=1,ZB=0)F_{B}\left(\cdot|Z^{A}=1,Z^{B}=0\right).

6.2.2 A U-Shape Restriction on Nonresponse Propensities

This section’s sensitivity analysis refines the worst-case bounds on the contrasts {DNB1(x)DNA1(x),x[t¯,t¯]}\{D^{1}_{N_{B}}(x)-D^{1}_{N_{A}}(x),x\in[\underline{t},\overline{t}]\} using the descriptive empirical evidence on the U-shaped form of the unit and wave nonresponse propensities with respect to income measures. This evidence on nonresponse are from exploratory logistic regressions whose estimation output is reported in Table A3.1 in Watson and Fry (2002) and Table 10.2 in Watson and Wooden (2009) for unit and wave nonresponse, respectively. Furthermore, they have found no statistically significant relationship with the income measures, which can be considered as weak evidence for this U-shaped form. It should be noted, however, that the validity of their tests rely on the correct specification of their model, which is likely misspecified. Thus, to take account of their findings and the likely misspecification of their model, we implement the U-shaped restriction on Prob(ZA=ZB=0|YA=x)\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{A}=x\right) and Prob(ZA=1,ZB=0|YB=x)\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}=x\right) through the structure described in Example 3.

For each x𝒳Kx\in\mathcal{X}_{K} and K{A,B}K\in\{A,B\}, an application of Bayes’ Theorem to the conditional probability P(ZA=ZB=0|YKx)P\left(Z^{A}=Z^{B}=0|Y_{K}\leq x\right) reveals its form as 1FK(x)xP(ZA=ZB=0|YK=v)𝑑FK(v)\frac{1}{F_{K}(x)}\int_{-\infty}^{x}P\left(Z^{A}=Z^{B}=0|Y_{K}=v\right)\,dF_{K}(v), with a similar expression for Prob(ZA=1,ZB=0|YBx)\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right). Therefore, we can encode this shape information on the nonresponse propensities using the bounds

δ00L00K(x)\displaystyle\delta_{00}\,L^{K}_{00}(x) Prob(ZA=ZB=0|YKx)U00K(x)δ00,K=A,B,and\displaystyle\leq\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{K}\leq x\right)\leq U^{K}_{00}(x)\,\delta_{00},\quad K=A,B,\text{and} (6.2)
δ10L10B(x)\displaystyle\delta_{10}\,L^{B}_{10}(x) Prob(ZA=1,ZB=0|YBx)U10B(x)δ10,\displaystyle\leq\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right)\leq U^{B}_{10}(x)\,\delta_{10}, (6.3)

where L00AL^{A}_{00}, U00AU^{A}_{00}, L00BL^{B}_{00}, U00BU^{B}_{00}, L10BL^{B}_{10}, and U10BU^{B}_{10} are CDFs on the common support [150000,106][-150000,10^{6}], satisfying L00K()U00K()L^{K}_{00}(\cdot)\leq U^{K}_{00}(\cdot) for K=A,B,K=A,B, and L10B()U10B()L^{B}_{10}(\cdot)\leq U^{B}_{10}(\cdot), and have U-shaped densities. Proposition D.3 describes the bounds on the contrast implied by this assumption for s+s\in\mathbb{Z}_{+}. For s=1s=1, they are given by

D¯NA1(x)\displaystyle\underline{D}_{N_{A}}^{1}(x) =FA(x|ZA=ZB=1)δ111L00A(x)δ00\displaystyle=F_{A}\left(x|Z^{A}=Z^{B}=1\right)\,\frac{\delta_{11}}{1-L^{A}_{00}(x)\delta_{00}}
+FA(x|ZA=1,ZB=0)δ101L00A(x)δ00and\displaystyle\qquad+F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\,\frac{\delta_{10}}{1-L^{A}_{00}(x)\delta_{00}}\quad\text{and} (6.4)
D¯NBs(x)\displaystyle\overline{D}_{N_{B}}^{s}(x) =FB(x|ZA=ZB=1)δ111U00B(x)δ00U10B(x)δ10,\displaystyle=F_{B}\left(x|Z^{A}=Z^{B}=1\right)\,\frac{\delta_{11}}{1-U^{B}_{00}(x)\delta_{00}-U^{B}_{10}(x)\delta_{10}}, (6.5)

for each x[t¯,t¯]x\in[\underline{t},\overline{t}]. Within our estimating function approach, they arise under the following specification of φNA,NB\varphi_{N_{A},N_{B}}: for each x[t¯,t¯]x\in[\underline{t},\overline{t}], φ1(x)=φ2(x)=δ11+δ101L00A(x)δ00\varphi_{1}(x)=\varphi_{2}(x)=-\frac{\delta_{11}+\delta_{10}}{1-L^{A}_{00}(x)\delta_{00}}, φ3(x)=0\varphi_{3}(x)=0, and φ4(x)=δ11+δ101U00B(x)δ00U10B(x)δ10\varphi_{4}(x)=-\frac{\delta_{11}+\delta_{10}}{1-U^{B}_{00}(x)\delta_{00}-U^{B}_{10}(x)\delta_{10}}.

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(a)
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(b)
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(c)
Figure 3: Scatter plots of (ξ¯w1,ξ¯w2,η¯w2)(\underline{\xi}_{w_{1}},\overline{\xi}_{w_{2}},\overline{\eta}_{w_{2}}) corresponding to “Reject the null” in (6.1)

Given the form of the bounds on the dominance contrast, we only need to specify L00AL^{A}_{00}, U00BU^{B}_{00} and U10BU^{B}_{10} to implement them. We specify them as elements of the family of Generalized Arcsine parametric family. This family has U-shaped PDFs given by

g(x;ξ)=π1sin(πξ)(xx¯)ξ(x¯x)ξ1,x[x¯,x¯],\displaystyle g(x;\xi)=\pi^{-1}\,\sin\left(\pi\,\xi\right)\,(x-\underline{x})^{-\xi}\,(\overline{x}-x)^{\xi-1},\quad x\in[\underline{x},\overline{x}],

where ξ(0,1)\xi\in(0,1) is a shape parameter, and [x¯,x¯]=[150000,106][\underline{x},\overline{x}]=[-150000,10^{6}] is the support. This parametric family is ordered with respect to the parameter ξ\xi as follows: ξ1ξ2G(x;ξ1)G(x;ξ2)\xi_{1}\leq\xi_{2}\implies G(x;\xi_{1})\leq G(x;\xi_{2}), where G(x,ξi)=150000xg(r;ξi)𝑑rG(x,\xi_{i})=\int_{-150000}^{x}g(r;\xi_{i})\,dr and ξi(0,1)\xi_{i}\in(0,1) for i=1,2i=1,2. The sensitivity analysis studies the sensitivity of the empirical outcome with respect to configurations of L00AL^{A}_{00}, U00BU^{B}_{00} and U10BU^{B}_{10} in this parametric family. Notably, the uniform distribution U[150000,106]U[-150000,10^{6}] is not an member of this parametric family. Hence, the inequalities (6.2) and (6.3) do not define a neighbourhood of the MCAR nonresponse propensities under this parametric shape restriction.

Next, we report the results of the sensitivity analysis of the event “Reject H0H_{0}” in the test problem (6.1) for each wave pair, with respect to the choice of L00AL^{A}_{00}, U00BU^{B}_{00} and U10BU^{B}_{10} within the Generalized Arcsine parametric family, where DNA1()D_{N_{A}}^{1}(\cdot) and DNB1()D_{N_{B}}^{1}(\cdot) are described in (6.4) and (6.5), respectively. Let L00A()=G(,ξ¯w1)L^{A}_{00}(\cdot)=G(\cdot,\underline{\xi}_{w_{1}}), U00B()=G(,ξ¯w2)U^{B}_{00}(\cdot)=G(\cdot,\overline{\xi}_{w_{2}}) and U10B()=G(,η¯w2)U^{B}_{10}(\cdot)=G(\cdot,\overline{\eta}_{w_{2}}). The testing procedure was implemented for all values of the triple (ξ¯w1,ξ¯w2,η¯w2)(\underline{\xi}_{w_{1}},\overline{\xi}_{w_{2}},\overline{\eta}_{w_{2}}) in the 3-dimensional grid Ξ={0.1,0,2,,0.9}3\Xi=\{0.1,0,2,\ldots,0.9\}^{3}.

Figure 3 reports the results of these tests using scatter plots, and all tests were conducted at the 5% significance level. The scatter of black dots in each panel of these figures correspond to the subset of Ξ\Xi given by Ξ1={(ξ¯w1,ξ¯w2,η¯w2)Ξ:“Reject H0 in (6.1)”}\Xi_{1}=\left\{(\underline{\xi}_{w_{1}},\overline{\xi}_{w_{2}},\overline{\eta}_{w_{2}})\in\Xi:\,\text{``Reject $H_{0}$ in~(\ref{eq - Test Problem Empirical s1})''}\right\}. The subset Ξ0=ΞΞ1\Xi_{0}=\Xi-\Xi_{1} of Ξ\Xi is where non-rejection of H0H_{0} has occurred. Let Ξ11,2\Xi^{1,2}_{1}, Ξ11,3\Xi^{1,3}_{1}, Ξ11,4\Xi^{1,4}_{1} be the set Ξ1\Xi_{1} but corresponding to the tests for pairwise comparison of waves 1 and 2, 1 and 3, and 1 and 4, respectively. Furthermore, define Ξ01,j=ΞΞ11,j\Xi^{1,j}_{0}=\Xi-\Xi^{1,j}_{1} for j=2,3,4j=2,3,4. From these figures observe that Ξ11,2Ξ11,3Ξ11,4\Xi^{1,2}_{1}\subset\Xi^{1,3}_{1}\subset\Xi^{1,4}_{1} and Ξ01,4Ξ01,3Ξ01,2\Xi^{1,4}_{0}\subset\Xi^{1,3}_{0}\subset\Xi^{1,2}_{0}, hold. These subset relationships also hold for each subfigure of Figures 3(a)3(c). This result is expected since the wave nonresponse rates, given by δ^10\hat{\delta}_{10} in Table 1, double when moving from comparisons between waves 1 and 2 to that of waves 1 and 4. This doubling has lowered the worst-case lower bound of population BB in the comparisons, enabling more configurations of the contrasts within the Generalized Arcsine parametric family to satisfy H1H_{1} in the sample, and hence, a chance at rejecting H0H_{0}.

Despite the prevalence of nonresponse, overall, the rejection event is a little sensitive to values of (ξ¯w1,ξ¯w2,η¯w2)Ξ(\underline{\xi}_{w_{1}},\overline{\xi}_{w_{2}},\overline{\eta}_{w_{2}})\in\Xi, as Ξ11,j\Xi^{1,j}_{1} consists of most elements of Ξ\Xi and Ξ01,j\Xi^{1,j}_{0} consists only of elements of Ξ\Xi where the test statistic equalled zero, for j=2,3,4j=2,3,4. In fact, the rejection event’s sensitivity declines with comparisons of wave 1 with later waves, as Ξ11,4\Xi^{1,4}_{1} is almost the entire grid Ξ\Xi. This empirical finding provides credible evidence at the 5% significance level that poverty among Australian households has declined between years 2001 to 2002, 2001 and 2003, and 2001 and 2004, according to the headcount ratio over their corresponding set of poverty lines given in Table 1.

7 Conclusion

We have proposed a comprehensive design-based framework for executing tests of restricted stochastic dominance with paired data from survey panels that accounts for the identification problem created by nonresponse. The methodology employs an estimating function procedure with nuisance functionals that can encode a broad spectrum of assumptions on nonreponse. Hence, practitioners can use our framework to perform a sensitivity analysis of testing conclusions based on the assumptions they are willing to entertain. We have illustrated the scope of our procedure using data from the HILDA survey in studying the sensitivity of their documented decrease in poverty between 2001 and 2004 in Australia using two types of assumptions on nonresponse. The first assumption embodies the divergence between missing data and observed outcomes through the Kolmogorov-Smirnov distance, while the second assumption constrains the shape of unit and wave nonresponse with incomes. We have found this decrease in poverty is (i) sensitive to departures from ignorability with the Kolmogorov-Smirnov neighborhood assumption, and (ii) relatively robust within a class of nonresponse propensities whose boundary is modeled semiparmetrically using CDFs of the Generalized Arcsine family of distributions.

8 Acknowledgement

Rami Tabri expresses gratitude to Brendan K. Beare, Elie T. Tamer, Isaiah Andrews, Aureo de Paula, Mervyn J. Silvapulle, and Christopher Walker for their valuable feedback. Special thanks to the Economics Department at Harvard University and the HILDA team at the Melbourne Institute: Applied Economic and Social Research, University of Melbourne, for their hospitality during his visit. We also thank Sarah C. Dahmann for her assistance with the data preparation for the empirical illustration

References

  • Abadie (2002) Abadie, A. (2002). Bootstrap tests for distributional treatment effects in instrumental variable models. Journal of the American Statistical Association 97(457), 284–292.
  • Abadie et al. (2020) Abadie, A., S. Athey, G. W. Imbens, and J. M. Wooldridge (2020). Sampling-based versus design-based uncertainty in regression analysis. Econometrica 88(1), 265–296.
  • Aitchison (1962) Aitchison, J. (1962). Large-sample restricted parametric tests. Journal of the Royal Statistical Society: Series B (Methodological) 24(1), 234–250.
  • Andrews and Shi (2017) Andrews, D. W. and X. Shi (2017). Inference based on many conditional moment inequalities. Journal of Econometrics 196(2), 275–287.
  • Andrews and Soares (2010) Andrews, D. W. and G. Soares (2010). Inference for Parameters Defined by Moment Inequalities using Generalized Moment Selection. Econometrica 78(1), 119–157.
  • Aryal and Gabrielli (2013) Aryal, G. and F. M. Gabrielli (2013). Testing for collusion in asymmetric first-price auctions. International Journal of Industrial Organization 31, 26–35.
  • Atkinson (1970) Atkinson, A. B. (1970). On the Measurement of Inequality. Journal of Economic Theory 2, 244–263.
  • Atkinson (1987) Atkinson, A. B. (1987). On the measurement of poverty. Econometrica 55(4), 749–764.
  • Barrett and Donald (2003) Barrett, G. F. and S. G. Donald (2003). Consistent tests for stochastic dominance. Econometrica 71(1), 71–104.
  • Berger (2020) Berger, Y. G. (2020). An empirical likelihood approach under cluster sampling with missing observations. Annals of the Institute of Statistical Mathematics 72, 91–121.
  • Bhattacharya (2005) Bhattacharya, D. (2005). Asymptotic inference from multi-stage samples. Journal of Econometrics 126(1), 145–171.
  • Bhattacharya (2007) Bhattacharya, D. (2007). Inference on inequality from household survey data. Journal of Econometrics 137(2), 674–707.
  • Blundell et al. (2007) Blundell, R., A. Gosling, H. Ichimura, and C. Meghir (2007). Changes in the distribution of male and female wages accounting for employment composition using bounds. Econometrica 75(2), 323–363.
  • Bourguignon (2018) Bourguignon, F. (2018). Simple adjustments of observed distributions for missing income and missing people. Journal of Economic Inequality 16, 171–188.
  • Chen and Sitter (1999) Chen, J. and R. R. Sitter (1999). A pseudo empirical likelihood approach to the effective use of auxiliary information in complex surveys. Statistica Sinica 9, 385–406.
  • Chen and Duclos (2011) Chen, W.-H. and J.-Y. Duclos (2011). Testing for poverty dominance: an application to canada. The Canadian Journal of Economics / Revue canadienne d’Economique 44(3), 781–803.
  • Şeker and Jenkins (2015) Şeker, S. D. and S. P. Jenkins (2015). Poverty trends in turkey. Journal of Economic Inequality 13(3), 401–424.
  • Davidson (2008) Davidson, R. (2008). Stochastic dominance. In M. Vernengo, E. P. Caldentey, and B. J. R. Jr (Eds.), The New Palgrave Dictionary of Economics. Palgrave Macmillan.
  • Davidson and Duclos (2013) Davidson, R. and J.-Y. Duclos (2013). Testing for restricted stochastic dominance. Econometric Reviews 32(1), 84–125.
  • Deaton (1997) Deaton, A. (1997). The Analysis of Household Surveys: A Microeconometric Approach to Development Policy. International Bank for Reconstruction and Development/The World Bank.
  • Deville and Sarndal (1992) Deville, J.-C. and C.-E. Sarndal (1992). Calibration estimators in survey sampling. Journal of the American Statistical Association 87(418), 376–382.
  • Donald and Hsu (2016) Donald, S. G. and Y.-C. Hsu (2016). Improving the power of tests of stochastic dominance. Econometric Reviews 35(4), 553–585.
  • Fakih et al. (2022) Fakih, A., P. Makdissi, W. Marrouch, R. V. Tabri, and M. Yazbeck (2022). A stochastic dominance test under survey nonresponse with an application to comparing trust levels in lebanese public institutions. Journal of Econometrics 228(2), 342–358.
  • Fong (2010) Fong, W. M. (2010). A stochastic dominance analysis of yen carry trades. Journal of Banking & Finance 34(6), 1237–1246.
  • Foster and Shorrocks (1988) Foster, J. E. and A. F. Shorrocks (1988). Poverty orderings. Econometrica 56(1), 173–177.
  • Fuller (2009) Fuller, W. A. (2009). Sampling Statistics. Wiley.
  • Godambe and Thompson (2009) Godambe, V. and M. E. Thompson (2009). Chapter 26 - estimating functions and survey sampling. In C. Rao (Ed.), Handbook of Statistics, Volume 29 of Handbook of Statistics, pp.  83–101. Elsevier.
  • Hájek (1971) Hájek, J. (1971). Comment on An Essay on the Logical Foundations of Survey Sampling, Part One. In A. DasGupta (Ed.), Selected Works of Debabrata Basu. Springer.
  • Harris and Mapp (1986) Harris, T. R. and H. P. Mapp (1986). A stochastic dominance comparison of water-conserving irrigation strategies. American Journal of Agricultural Economics 68(2), 298–305.
  • Hayes (2008) Hayes, C. (2008). Hilda standard errors: A users guide. HILDA Project Technical Paper Series 2/08, Melbourne Institute of Applied Economic & Social Research, The University of Melbourne.
  • Horowitz and Manski (2006) Horowitz, J. L. and C. F. Manski (2006). Identification and estimation of statistical functionals using incomplete data. Journal of Econometrics 132(2), 445–459.
  • Imbens and Lancaster (1994) Imbens, G. W. and T. Lancaster (1994). Combining micro and macro data in microeconometric models. The Review of Economic Studies 61(4), 655–680.
  • Kaur et al. (1994) Kaur, A., B. Prakasa Rao, and H. Singh (1994). Testing for Second Order Stochastic Domiance of Two Distributions. Econometric Theory 10, 849–866.
  • Kline and Santos (2013) Kline, P. and A. Santos (2013). Sensitivity to missing data assumptions: Theory and an evaluation of the u.s. wage structure. Quantitative Economics 4(2), 231–267.
  • Linton et al. (2005) Linton, O., E. Maasoumi, and Y.-J. Whang (2005). Consistent testing for stochastic dominance under general sampling schemes. The Review of Economic Studies 72(3), 735–765.
  • Linton et al. (2010) Linton, O., K. Song, and Y.-J. Whang (2010). An Improved Bootstrap Test for Stochastic Dominance. Journal Of Econometrics 154, 186–202.
  • Lok and Tabri (2021) Lok, T. M. and R. V. Tabri (2021). An improved bootstrap test for restricted stochastic dominance. Journal of Econometrics.
  • Lustig (2017) Lustig, N. (2017). The mising rich in household surveys: causes and correction approaches. Technical Report 75, Tulane University.
  • Manski (2016) Manski, C. F. (2016). Credible interval estimates for official statistics with survey nonresponse. Journal of Econometrics 191(2), 293–301.
  • McFadden (1989) McFadden, D. (1989). Testing for stochastic dominance. In T. B. Fomby and T. K. Seo (Eds.), Studies in the Economics of Uncertainty, pp.  113–134. Springer.
  • Minviel and Benoit (2022) Minviel, J. J. and M. Benoit (2022). Economies of diversification and stochastic dominance analysis in french mixed sheep farms. Agricultural and Resource Economics Review 51(1), 156–177.
  • Neyman (1934) Neyman, J. (1934). On the two different aspects of the representative method: The method of stratified sampling and the method of purposive selection. Journal of the Royal Statistical Society 97(4), 558–625.
  • Parente and Smith (2017) Parente, P. M. and R. J. Smith (2017). Tests of additional conditional moment restrictions. Journal of Econometrics 200(1), 1–16.
  • Qin et al. (2009) Qin, J., B. Zhang, and D. H. Y. Leung (2009). Empirical likelihood in missing data problems. Journal of the American Statistical Association 104(488), 1492–1503.
  • Raubertas et al. (1986) Raubertas, R. F., C.-I. C. Lee, and E. V. Nordheim (1986). Hypothesis tests for normal means constrained by linear inequalities. Communications in Statistics - Theory and Methods 15(9), 2809–2833.
  • Rubin-Bleuer and Kratina (2005) Rubin-Bleuer, S. and I. S. Kratina (2005). On the two-phase framework for joint model and design-based inference. The Annals of Statistics 33(6), 2789–2810.
  • Sarndal and Lundstrom (2005) Sarndal, C. E. and S. Lundstrom (2005). Estimation in Surveys with Nonresponse. Wiley & Sons.
  • Taylor (2010) Taylor, M. F. (2010). British Household Panel Survey User Manual Volume A: Introduction, Technical Report and Appendices. University of Essex.
  • Wang (2012) Wang, J. C. (2012). Sample distribution function based goodness-of-fit test for complex surveys. Computational Statistics & Data Analysis 56(3), 664–679.
  • Wang et al. (2022) Wang, Z., L. Peng, and J. K. Kim (2022, 04). Bootstrap Inference for the Finite Population Mean under Complex Sampling Designs. Journal of the Royal Statistical Society Series B: Statistical Methodology 84(4), 1150–1174.
  • Watson and Fry (2002) Watson, N. and T. R. Fry (2002). The household, income and labour dynamics in australia (hilda) survey: Wave 1 weighting. HILDA Project Technical Paper Series 03/02, Melbourne Institute of Applied Economic & Social Research, The University of Melbourne.
  • Watson and Wooden (2002) Watson, N. and M. Wooden (2002). The household, income and labour dynamics in australia (hilda) survey: Wave 1 survey methodology. HILDA Project Technical Paper Series 01/02, Melbourne Institute of Applied Economic & Social Research, The University of Melbourne.
  • Watson and Wooden (2004) Watson, N. and M. Wooden (2004). Assessing the quality of the hilda survey wave 2 data. HILDA Project Technical Paper Series 5/04, Melbourne Institute of Applied Economic & Social Research, The University of Melbourne.
  • Watson and Wooden (2009) Watson, N. and M. Wooden (2009). Identifying Factors Affecting Longitudinal Survey Response, Chapter 10, pp.  157–181. John Wiley & Sons, Ltd.
  • Whang (2019) Whang, Y.-J. (2019). Econometric Analysis of Stochastic Dominance: Concepts, Methods, Tools and Applications. Cambridge University Press.
  • Wilkins (2001) Wilkins, R. (2001). Poverty lines: Australia september quarter 2001. Online Newsletter. Melbourne Institute of Applied Economic and Social Research, The University of Melbourne.
  • Wilkins (2002) Wilkins, R. (2002). Poverty lines: Australia march quarter 2002. Online Newsletter. Melbourne Institute of Applied Economic and Social Research, The University of Melbourne.
  • Wilkins (2003) Wilkins, R. (2003). Poverty lines: Australia december quarter 2003. Online Newsletter. Melbourne Institute of Applied Economic and Social Research, The University of Melbourne.
  • Wilkins (2004) Wilkins, R. (2004). Poverty lines: Australia september quarter 2004. Online Newsletter. Melbourne Institute of Applied Economic and Social Research, The University of Melbourne.
  • Wilkins et al. (2022) Wilkins, R., E. Vera-Toscano, F. Botha, M. Wooden, and T.-A. Trinh (2022). The 17th annual statistical report of the hilda survey. Hilda statistical report series, Melbourne Institute of Applied Economic & Social Research, The University of Melbourne.
  • Wu and Lu (2016) Wu, C. and W. W. Lu (2016). Calibration weighting methods for complex surveys. International Statistical Review / Revue Internationale de Statistique 84(1), 79–98.
  • Wu and Rao (2006) Wu, C. and J. N. K. Rao (2006). Pseudo-empirical likelihood ratio confidence intervals for complex surveys. The Canadian Journal of Statistics / La Revue Canadienne de Statistique 34(3), 359–375.
  • Zhao et al. (2020) Zhao, P., D. Haziza, and C. Wu (2020). Survey weighted estimating equation inference with nuisance functionals. Journal of Econometrics 216(2), 516–536.
  • Zheng (2002) Zheng, B. (2002). Testing lorenz curves with non-simple random samples. Econometrica 70(3), 1235–1243.

Appendix A Appendix

This appendix provides the supplementary material to the paper. It is organized as follows.

  • Appendix B presents the proofs of Theorems 12, and 3.

  • Appendix C presents the technical Lemmas used in the proofs of Theorems 2 and 3.

  • Appendix D presents the technical result steps for deriving the bounds in the Examples outlined in Section 2.2.

  • Appendix E present the technical details concerning Section 5.

Appendix B Proofs of Theorems 1 - 3

B.1 Proof of Theorem 1

Proof.

The proof follows steps identical to those in the proof of Theorem 1 in Fakih et al. (2022), but with adjustments for the test statistic. We first show (4.2)\implies (4.3). The proof proceeds by the direct method. Suppose that (4.2) holds, and let {ΠNA,NB}NA,NB=1+𝕎0.\left\{\Pi_{N_{A},N_{B}}\right\}_{N_{A},N_{B}=1}^{+\infty}\in\mathbb{W}_{0}. Then

𝔼[1[LR>c(α)]ΠNA,NB]supΠNA,NB0E[1[LR>c(α)]Π]NA,NB,\displaystyle\mathbbm{E}\left[1[LR>c(\alpha)]\mid\Pi_{N_{A},N_{B}}\right]\leq\sup_{\Pi\in\mathcal{M}^{0}_{N_{A},N_{B}}}E\left[1[LR>c(\alpha)]\mid\Pi\right]\;\forall N_{A},N_{B}, (B.1)

holds. Taking the limit superiors on both sides of the inequality (B.1) implies the inequality (4.3). As the sequence {ΠNA,NB}NA,NB=1+𝕎0\left\{\Pi_{N_{A},N_{B}}\right\}_{N_{A},N_{B}=1}^{+\infty}\in\mathbb{W}_{0} was arbitrary, this inequality holds for all such sequences.

Now we shall prove the reverse direction:(4.3)\implies (4.2). The proof proceeds by contraposition. Suppose that (4.2) does not hold, i.e.,

lim supNA,NB+supΠNA,NB0𝔼[1[LR>c(α)]Π]\displaystyle\limsup_{N_{A},N_{B}\rightarrow+\infty}\sup_{\Pi\in\mathcal{M}^{0}_{N_{A},N_{B}}}\mathbbm{E}\left[1[LR>c(\alpha)]\mid\Pi\right] >α.\displaystyle>\alpha. (B.2)

Then we have to construct a sequence {ΠNA,NB}NA,NB=1+𝕎0\left\{\Pi_{N_{A},N_{B}}\right\}_{N_{A},N_{B}=1}^{+\infty}\in\mathbb{W}_{0} such that

lim supNA,NB+𝔼[1[LR(A,B)>c(α)]ΠNA,NB]>α\displaystyle\limsup_{N_{A},N_{B}\rightarrow+\infty}\mathbbm{E}\left[1[LR^{(A,B)}>c(\alpha)]\mid\Pi_{N_{A},N_{B}}\right]>\alpha

to prove the result. To that end, the condition (B.2) implies the largest subsequential limit of the sequence {supΠNA,NB0𝔼[1[LR>c(α)]Π]}NA,NB=1+\left\{\sup_{\Pi\in\mathcal{M}^{0}_{N_{A},N_{B}}}\mathbbm{E}\left[1[LR>c(\alpha)]\mid\Pi\right]\right\}_{N_{A},N_{B}=1}^{+\infty} exceeds α.\alpha. Thus, there is a sequence {NA,m,NB,m}m=1+\{N_{A,m},N_{B,m}\}_{m=1}^{+\infty} such that the limit of {supΠNA,m,NB,m0𝔼[1[LR>c(α)]Π]}m=1+\left\{\sup_{\Pi\in\mathcal{M}^{0}_{N_{A,m},N_{B,m}}}\mathbbm{E}\left[1[LR>c(\alpha)]\mid\Pi\right]\right\}_{m=1}^{+\infty} exceeds α,;\alpha,; e.g., the limit is equal to α+ν\alpha+\nu where ν>0.\nu>0. Now let ϵ>0\epsilon>0 be such that ν>ϵ>0.\nu>\epsilon>0. For each mm there exists ΠNA,m,NB,mNA,m,NB,m0\Pi^{\prime}_{N_{A,m},N_{B,m}}\in\mathcal{M}^{0}_{N_{A,m},N_{B,m}} such that

𝔼[1[LR>c(α)]ΠNA,m,NB,m]>supΠNA,m,NB,m0E[1[LR>c(α)]Π]ϵ.\displaystyle\mathbbm{E}\left[1[LR>c(\alpha)]\mid\Pi^{\prime}_{N_{A,m},N_{B,m}}\right]>\sup_{\Pi\in\mathcal{M}^{0}_{N_{A,m},N_{B,m}}}E\left[1[LR>c(\alpha)]\mid\Pi\right]-\epsilon. (B.3)

Now taking limit superior of both sides of (B.3) with respect to m,m, yields

lim supm+𝔼[1[LR>c(α)]ΠNA,m,NB,m]\displaystyle\limsup_{m\rightarrow+\infty}\mathbbm{E}\left[1[LR>c(\alpha)]\mid\Pi^{\prime}_{N_{A,m},N_{B,m}}\right] lim supm+supΠNA,m,NB,m0𝔼[1[LR>c(α)]Π]ϵ\displaystyle\geq\limsup_{m\rightarrow+\infty}\sup_{\Pi\in\mathcal{M}^{0}_{N_{A,m},N_{B,m}}}\mathbbm{E}\left[1[LR>c(\alpha)]\mid\Pi\right]-\epsilon
>α+νϵ>α.\displaystyle>\alpha+\nu-\epsilon>\alpha.

Thus, we have constructed a sequence of populations {ΠNA,m,NB,m}m=1+𝕎0\left\{\Pi^{\prime}_{N_{A,m},N_{B,m}}\right\}_{m=1}^{+\infty}\in\mathbb{W}_{0} with the desired property. This concludes the proof. ∎

B.2 Proof of Theorem 2

Proof.

We proceed by the direct method. Fix an α(0,1)\alpha\in(0,1). This proof demonstrates that the testing procedure is uniformly asymptotically valid by showing that the test has level α\alpha for all possible subsequences of finite populations based on sequences in 𝕎0\mathbb{W}_{0}. The subsequences where the asymptotic size (4.3) will be largest is where we have dominance within sample and we are on the boundary of the model of the null hypothesis H01H_{0}^{1}. Let Υ\Upsilon denote the event of dominance in sample, that is: D¯^As(x)D¯^Bs(x)=θ^(x;φ^(x))<0x[t¯,t¯].\widehat{\overline{D}}_{A}^{s}(x)-\widehat{\underline{D}}_{B}^{s}(x)=\hat{\theta}(x;\hat{\varphi}(x))<0\quad\forall x\in[\underline{t},\overline{t}]. Let {ΠNAm,NBm}m=1\{\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\}_{m=1}^{\infty} be a subsequence of {ΠNA,NB}NA,NB=1𝕎0\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}\in\mathbb{W}_{0}. We focus on subsequences that give the event Υ\Upsilon the highest probability (as otherwise LR=0LR=0). Fix an x[t¯,t¯]x\in[\underline{t},\overline{t}] arbitrarily, and let τ^m(x)=θ^(x;φ^(x))Var(θ^(x;φ^(x))ΠNAm,NBm)ΠNAm,NBm\hat{\tau}_{m}(x)=\dfrac{\hat{\theta}(x;\hat{\varphi}(x))}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)}}\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}} τm(x)=θNAm,NBm(x;φNAm,NBm(x))Var(θ^(x;φ^(x))ΠNAm,NBm)ΠNAm,NBm\tau_{m}(x)=\dfrac{\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x;\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x)\right)}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)}}\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}. Observe that τ^m(x)=τ^m(x)τm(x)+τm(x)\hat{\tau}_{m}(x)=\hat{\tau}_{m}(x)-\tau_{m}(x)+\tau_{m}(x), so that under Conditions 5 and 7 of Assumption 2, as mm\rightarrow\infty, τ^m()\hat{\tau}_{m}(\cdot) must converges weakly to a Gaussian process with mean

C(x)=limm+τm(x)=limm+θNAm,NBm(x;φNAm,NBm(x))Var(θ^(x;φ^(x))ΠNAm,NBm)ΠNAm,NBm.\displaystyle C(x)=\lim_{m\rightarrow+\infty}\tau_{m}(x)=\lim_{m\rightarrow+\infty}\dfrac{\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x;\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x)\right)}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)}}\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}.

Therefore, limm𝔼[𝟙[Υ]ΠNAm,NBm]=limmProb(maxx[t¯,t¯]θ^(x;φ^(x))<0ΠNAm,NBm){\displaystyle\lim_{m\rightarrow\infty}\mathbbm{E}\left[\mathbbm{1}[\Upsilon]\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right]=\lim_{m\rightarrow\infty}\text{Prob}\left(\max\limits_{x\in[\underline{t},\overline{t}]}\hat{\theta}(x;\hat{\varphi}(x))<0\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)}, which equals limmProb(maxx[t¯,t¯]τ^m(x)<0ΠNAm,NBm)\lim_{m\rightarrow\infty}\text{Prob}\left(\max\limits_{x\in[\underline{t},\overline{t}]}\hat{\tau}_{m}(x)<0\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right). Now using the weak convergence of τ^m()\hat{\tau}_{m}(\cdot), this probability simplifies to

limm𝔼[𝟙[Υ]ΠNAm,NBm]=Prob(maxx[t¯,t¯](𝔾(x)+C(x))<0).\displaystyle\lim_{m\rightarrow\infty}\mathbbm{E}\left[\mathbbm{1}[\Upsilon]\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right]=\text{Prob}\left(\max\limits_{x\in[\underline{t},\overline{t}]}\left(\mathbb{G}(x)+C(x)\right)<0\right). (B.4)

This probability (B.4) will be highest for subsequences of finite populations within the model of the null hypothesis H01H_{0}^{1} where we have a unique x[t¯,t¯]x^{*}\in[\underline{t},\overline{t}] such that C(x)=0C(x^{*})=0 and C(x)=x[t¯,t¯]{x}C(x)=-\infty\ \forall x\in[\underline{t},\overline{t}]\setminus\{x^{*}\}. This corresponds to finite populations in the boundary of the model of the null hypothesis H01H_{0}^{1}. Thus, consider two types of subsequences of finite populations. Firstly, subsequences that drift on the boundary: ΠNAm,NBmNAm,NBm0\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\in\partial\mathcal{M}^{0}_{{N_{A}}_{m},{N_{B}}_{m}} m\forall m\in\mathbb{N}. Secondly, subsequences of the finite populations that drift to the boundary of the null model from its interior. Starting with the first case, as we are on the boundary for each mm\in\mathbb{N}, we have at least one x[t¯,t¯]x\in[\underline{t},\overline{t}] such that D¯NAms(x)=D¯NBms(x)\overline{D}_{{N_{A}}_{m}}^{s}(x)=\underline{D}_{{N_{B}}_{m}}^{s}(x). For a given mm\in\mathbb{N} let xm=min{x[t¯,t¯]:θNAm,NBm(x;φNAm,NBm(x))=0}x_{m}=\min\left\{x\in[\underline{t},\overline{t}]\;:\;\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x;\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x)\right)=0\right\}. Then using the definition of the LR test statistic (3.2): for each mm\in\mathbb{N}

𝔼(𝟙[LR>c(α)]ΠNAm,NBm)𝔼(𝟙[2(LURLR(xm))Deff^(xm)>c(α)]ΠNAm,NBm)\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)\leq\mathbbm{E}\left(\mathbbm{1}\left[\frac{2(L_{UR}-L_{R}(x_{m}))}{\widehat{\text{Deff}}(x_{m})}>c(\alpha)\right]\,\mid\,\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right) (B.5)

holds. Now by Lemma C.2 and taking the limit superior on both sides of (B.5), it follows that
lim supm𝔼(𝟙[LR>c(α)]ΠNAm,NBm)α\limsup_{m\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)\leq\alpha since

lim supm𝔼(𝟙[2(LURLR(xm))Deff^(xm)>c(α)]ΠNAm,NBm)=α,\displaystyle\limsup_{m\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}\left[\frac{2(L_{UR}-L_{R}(x_{m}))}{\widehat{\text{Deff}}(x_{m})}>c(\alpha)\right]\,\mid\,\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)=\alpha,

and the limiting distribution of {2(LURLR(xm))/Deff^(xm)ΠNAm,NBm}m=1\{2(L_{UR}-L_{R}(x_{m}))/\widehat{\text{Deff}}(x_{m})\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\}_{m=1}^{\infty} is χ12\chi_{1}^{2}.

Now focusing on the second case, we have that the subsequence of finite populations drifting to the boundary as mm\rightarrow\infty and let xe[t¯,t¯]x_{e}\in[\underline{t},\overline{t}] be such that C(xe)=0C(x_{e})=0 and C(x)=C(x)=-\infty for all x[t¯,t¯]{xe}x\in[\underline{t},\overline{t}]\setminus\{x_{e}\}. We utilise the inequality (B.5) and replace xmx_{m} with xex_{e}. Then taking the limit superior over both sides and applying Lemma C.3, we must have that lim supm𝔼(𝟙[LR>c(α)]ΠNAm,NBm)α\limsup_{m\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\,\mid\,\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)\leq\alpha holds, since

lim supm𝔼(𝟙[2(LURLR(xe))Deff^(xe)>c(α)]ΠNAm,NBm)=α.\displaystyle\limsup_{m\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}\left[\frac{2(L_{UR}-L_{R}(x_{e}))}{\widehat{\text{Deff}}(x_{e})}>c(\alpha)\right]\,\mid\,\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)=\alpha.

Note that Lemma C.3 establishes that limiting distribution of {2(LURLR(xe))/Deff^(xe)ΠNAm,NBm}m=1\{2(L_{UR}-L_{R}(x_{e}))/\widehat{\text{Deff}}(x_{e})\,\mid\,\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\}_{m=1}^{\infty} as χ12\chi_{1}^{2}. This concludes the proof. ∎

B.3 Proof of Theorem 3

Proof.

There are two possible cases for the sequences of finite populations which we examine under the alternative. Firstly, we consider sequences of finite populations that are uniformly bounded away from the boundary of the null hypothesis. Secondly, we consider sequences of finite populations that converges to NA,NB1\partial\mathcal{M}_{N_{A},N_{B}}^{1}, the boundary of the model of the null hypothesis as NA,NBN_{A},N_{B}\rightarrow\infty.

Proceeding under the first case via the direct method, fix an ε>0\varepsilon>0. Consider a sequence of finite populations {ΠNA,NB}NA,NB=1𝕎1(ε)\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}\in\mathbb{W}_{1}(\varepsilon). For any {ΠNA,NB}NA,NB=1𝕎1(ε)\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}\in\mathbb{W}_{1}(\varepsilon) we have that C(x)=C(x)=-\infty for all x[t¯,t¯]x\in[\underline{t},\overline{t}]. Let Υ\Upsilon denote the event of dominance within sample: i.e., the event maxx[t¯,t¯]θ^(x;φ^(x))<0\max_{x\in[\underline{t},\overline{t}]}\hat{\theta}(x;\hat{\varphi}(x))<0. Using that C(x)=C(x)=-\infty for all x[t¯,t¯]x\in[\underline{t},\overline{t}] and arguments similar to those in the proof of Theorem 2, it follows that limNA,NB𝔼[𝟙[Υ]ΠNA,NB]=1\lim_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}[\mathbbm{1}[\Upsilon]\,\mid\,\Pi_{N_{A},N_{B}}]=1. Consequently, the event Υ\Upsilon occurs with probability tending to unity as NA,NB+N_{A},N_{B}\rightarrow+\infty, and hence, LR=minx[t¯,t¯]2(LURLR(x))Deff^(x)LR=\min_{x\in[\underline{t},\overline{t}]}\frac{2(L_{UR}-L_{R}(x))}{\widehat{\text{Deff}}(x)} with probability tending to unity as NA,NB+N_{A},N_{B}\rightarrow+\infty. Now for each x[t¯,t¯]x\in[\underline{t},\overline{t}], applying Lemma C.5 to the sequence {2(LURLR(x))/Deff^(x)ΠNA,NB}NA,NB=1\{2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\mid\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}, we have that 2(LURLR(x))/Deff^(x)PasNA,NB2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\operatorname*{\overset{P}{\longrightarrow}}\infty\ \text{as}\ N_{A},N_{B}\rightarrow\infty. Accordingly, the form of LRLR implies LRΠNA,NBP+LR\mid\Pi_{N_{A},N_{B}}\stackrel{{\scriptstyle P}}{{\longrightarrow}}+\infty. Since the critical value c(α)c(\alpha) is fixed and finite, it follows that limNA,NB+𝔼[𝟙LR>c(α)]ΠNA,NB]=1\lim_{N_{A},N_{B}\rightarrow+\infty}\mathbbm{E}\left[\mathbbm{1}LR>c(\alpha)]\mid\Pi_{N_{A},N_{B}}\right]=1. This concludes the proof for this case.

Now focusing on the second case, we again proceed via the direct method. Let ε=0\varepsilon=0; therefore, the sequence of finite populations {ΠNA,NB}NA,NB=1𝕎1(0)\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}\in\mathbb{W}_{1}(0). Consequently, there will be at least one x[t¯,t¯]x\in[\underline{t},\overline{t}] such that C(x)=0C(x)=0. Let X0={x[t¯,t¯]:C(x)=0}X_{0}=\{x\in[\underline{t},\overline{t}]:C(x)=0\}. By contrast with the previous case, the limiting probability of the event Υ\Upsilon is Prob(maxxX0(𝔾(x)+C(x))<0)=Prob(maxxX0𝔾(x)<0)\text{Prob}\left(\max\limits_{x\in X_{0}}\left(\mathbb{G}(x)+C(x)\right)<0\right)=\text{Prob}\left(\max\limits_{x\in X_{0}}\mathbb{G}(x)<0\right), by arguments similar to those in the proof of Theorem 2. As this limiting probability is not necessarily equal to unity, we investigate the asymptotic power of the test on the event Υ\Upsilon, since for each NA,NBN_{A},N_{B}\in\mathbb{N} the equalities 𝔼(𝟙[LR>c(α)]ΠNA,NB)=𝔼(𝟙[LR>c(α),Υ]ΠNA,NB)\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\mid\Pi_{N_{A},N_{B}}\right)=\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha),\Upsilon]\mid\Pi_{N_{A},N_{B}}\right), hold, because ΥcLR=0\Upsilon^{c}\implies LR=0. Hence, limNA,NB𝔼(𝟙[LR>c(α)]ΠNA,NB)=limNA,NB𝔼(𝟙[LR>c(α),Υ]ΠNA,NB)\lim_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha)]\mid\Pi_{N_{A},N_{B}}\right)=\lim_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha),\Upsilon]\mid\Pi_{N_{A},N_{B}}\right), holds. Now Lemma C.5 establishes that 2(LURLR(x))/Deff^(x)PasNA,NB2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\operatorname*{\overset{P}{\longrightarrow}}\infty\ \text{as}\ N_{A},N_{B}\rightarrow\infty, holds, for each x[t¯,t¯]X0x\in[\underline{t},\overline{t}]\setminus X_{0}. Furthermore, Lemma C.6 establishes that 2(LURLR(x))/Deff^(x)dχ12asNA,NB2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\operatorname*{\overset{d}{\longrightarrow}}\chi_{1}^{2}\ \text{as}\ N_{A},N_{B}\rightarrow\infty, holds, for each xX0x\in X_{0}. Therefore, on the event Υ\Upsilon and asympotically, the rejection event is characterized as LR>c(α)minxX02(LURLR(x))Deff^(x)>c(α)LR>c(\alpha)\iff\min_{x\in X_{0}}\frac{2(L_{UR}-L_{R}(x))}{\widehat{\text{Deff}}(x)}>c(\alpha). Hence, limNA,NB𝔼(𝟙[LR>c(α),Υ]ΠNA,NB)\lim_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}[LR>c(\alpha),\Upsilon]\mid\Pi_{N_{A},N_{B}}\right) equals the limiting probability
limNA,NB𝔼(𝟙[minxX02(LURLR(x))Deff^(x)>c(α),Υ]ΠNA,NB)\lim_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}\left(\mathbbm{1}\left[\min_{x\in X_{0}}\frac{2(L_{UR}-L_{R}(x))}{\widehat{\text{Deff}}(x)}>c(\alpha),\Upsilon\right]\mid\Pi_{N_{A},N_{B}}\right). By Lemma C.6, this resulting limit equals Prob(𝔾2(x)>c(α)xX0,maxxX0𝔾(x)<0)\text{Prob}\left(\mathbb{G}^{2}(x)>c(\alpha)\,\forall x\in X_{0},\max\limits_{x\in X_{0}}\mathbb{G}(x)<0\right) as we show the statistics {2(LURLR(x))Deff^(x),xX0}\left\{\frac{2(L_{UR}-L_{R}(x))}{\widehat{\text{Deff}}(x)},x\in X_{0}\right\} converge in distribution to {𝔾2(x),xX0}\left\{\mathbb{G}^{2}(x),x\in X_{0}\right\} pointwise in xX0x\in X_{0}. This concludes the proof. ∎

Appendix C Technical Lemmas

C.1 Solution to PELF (3.1)

Here we develop the solution to the PELF, described by (3.1). For a given population ΠNA,NB\Pi_{N_{A},N_{B}} suppose we have access to a panel survey sample V𝒰AV\in\mathcal{U}_{A}. Firstly, we determine the solution to the unconstrained problem LURL_{UR}. Then for each x[t¯,t¯]x\in[\underline{t},\overline{t}], we determine the solution to the constrained optimisation problem denoted by LR(x)L_{R}(x). The unconstrained optimisation problem is described by:

maxp(0,1]niUWilog(pi)subject toiUWipi=1,\max_{\vec{p}\in(0,1]^{n}}\sum_{i\in U}W^{\prime}_{i}\log(p_{i})\quad\text{subject to}\quad\sum_{i\in U}W^{\prime}_{i}p_{i}=1, (C.1)

where U={iV:ZiA=1}U=\{i\in V:Z^{A}_{i}=1\}, and {Wi:iU}\{W^{\prime}_{i}:i\in U\} satisfies (2.12) so that iUWi=n\sum_{i\in U}W^{\prime}_{i}=n, holds. The corresponding Lagrangian is given by:

=iUWilog(pi)λ(iUWipi1)\mathcal{L}=\sum_{i\in U}W^{\prime}_{i}\log(p_{i})-\lambda\left(\sum_{i\in U}W^{\prime}_{i}p_{i}-1\right)

The First Order Conditions are, taking them with respect to i for generality:

pi\displaystyle\dfrac{\partial\mathcal{L}}{\partial p_{i}} =WipiλWi=0,iU\displaystyle=\dfrac{W^{\prime}_{i}}{p_{i}}-\lambda W^{\prime}_{i}=0,\quad\forall i\in U (C.2)
λ\displaystyle\dfrac{\partial\mathcal{L}}{\partial\lambda} =iUWipi1=0,and\displaystyle=\sum_{i\in U}W_{i}p_{i}-1=0,\ \text{and} (C.3)

Multiplying (C.2) by pip_{i} and then summing over i=1,2,,ni=1,2,\ldots,n

WiλWipi=0\displaystyle W^{\prime}_{i}-\lambda W^{\prime}_{i}p_{i}=0
iUWi=λiUWipi\displaystyle\sum_{i\in U}W^{\prime}_{i}=\lambda\sum_{i\in U}W^{\prime}_{i}p_{i}
using (C.3) and (2.12)
\displaystyle\implies n=λ\displaystyle n=\lambda (C.4)

Then substituting (C.4) into (C.2) and solving for pip_{i}, we obtain:

WinWipi=0\displaystyle W^{\prime}_{i}-nW^{\prime}_{i}p_{i}=0
1npi=0\displaystyle 1-np_{i}=0
\displaystyle\implies pi=1niU\displaystyle p_{i}=\dfrac{1}{n}\quad\forall i\in U (C.5)

Therefore, using (C.5) we have that the unrestricted log-likelihood is given by:

LUR=iUWilog(1n)L_{UR}=\sum_{i\in U}W^{\prime}_{i}\log\left(\frac{1}{n}\right) (C.6)

The constrained maximisation problem of the PELF corresponds to the following optimisation problem, where the last restriction imposes the moment equality for x[t¯,t¯]x\in[\underline{t},\overline{t}] corresponding to the boundary of the null hypothesis H01H_{0}^{1}:

maxp(0,1]n\displaystyle\max_{\vec{p}\in(0,1]^{n}} iUWilog(pi)\displaystyle\sum_{i\in U}W^{\prime}_{i}\log(p_{i}) (C.7)
subject to iUWipi=1\displaystyle\sum_{i\in U}W^{\prime}_{i}p_{i}=1
iUWipiHi(x;φ^(x))=0\displaystyle\sum_{i\in U}W^{\prime}_{i}p_{i}H_{i}(x;\hat{\varphi}(x))=0

The corresponding Lagrangian is given by:

=iUWilog(pi)λ(iUWipi1)κ(iUWipiHi(x;φ^(x)))\mathcal{L}=\sum_{i\in U}W^{\prime}_{i}\log(p_{i})-\lambda\left(\sum_{i\in U}W^{\prime}_{i}p_{i}-1\right)-\kappa\left(\sum_{i\in U}W^{\prime}_{i}p_{i}H_{i}(x;\hat{\varphi}(x))\right)

The First Order Conditions are

pi\displaystyle\dfrac{\partial\mathcal{L}}{\partial p_{i}} =WipiλWiκWiHi(x;φ^(x))=0,iU\displaystyle=\dfrac{W^{\prime}_{i}}{p_{i}}-\lambda W^{\prime}_{i}-\kappa W^{\prime}_{i}H_{i}(x;\hat{\varphi}(x))=0,\quad\forall i\in U (C.8)
λ\displaystyle\dfrac{\partial\mathcal{L}}{\partial\lambda} =iUWipi1=0,\displaystyle=\sum_{i\in U}W^{\prime}_{i}p_{i}-1=0, (C.9)
κ\displaystyle\dfrac{\partial\mathcal{L}}{\partial\kappa} =iUWipiHi(x;φ^(x))=0.\displaystyle=\sum_{i\in U}W^{\prime}_{i}p_{i}H_{i}(x;\hat{\varphi}(x))=0. (C.10)

Multiplying (C.8) by pip_{i} then summing across iUi\in U

WiλWipiκWipiHi(x;φ^(x))=0\displaystyle W^{\prime}_{i}-\lambda W^{\prime}_{i}p_{i}-\kappa W^{\prime}_{i}p_{i}H_{i}(x;\hat{\varphi}(x))=0
iUWiλiUWipiκiUWipiHi(x;φ^(x))=0\displaystyle\sum_{i\in U}W^{\prime}_{i}-\lambda\sum_{i\in U}W^{\prime}_{i}p_{i}-\kappa\sum_{i\in U}W^{\prime}_{i}p_{i}H_{i}(x;\hat{\varphi}(x))=0
using (C.9), (C.10) and that iUWi=n\sum_{i\in U}W^{\prime}_{i}=n
nλ=0\displaystyle n-\lambda=0
\displaystyle\implies λ=n.\displaystyle\lambda=n. (C.11)

We then substitute (C.11) into (C.8) and solve for pip_{i}

WipinWiκWiHi(x;φ^(x))=0\displaystyle\dfrac{W^{\prime}_{i}}{p_{i}}-nW^{\prime}_{i}-\kappa W^{\prime}_{i}H_{i}(x;\hat{\varphi}(x))=0
1pinκHi(x;φ^(x))=0\displaystyle\dfrac{1}{p_{i}}-n-\kappa H_{i}(x;\hat{\varphi}(x))=0
1pi=n+κHi(x;φ^(x))\displaystyle\dfrac{1}{p_{i}}=n+\kappa H_{i}(x;\hat{\varphi}(x))
\displaystyle\implies pi=1n+κHi(x;φ^(x))iU.\displaystyle p_{i}=\dfrac{1}{n+\kappa H_{i}(x;\hat{\varphi}(x))}\quad\forall i\in U. (C.12)

Interpreting this result, κ\kappa is the cost of imposing the null hypothesis H01H_{0}^{1}. The more readily the data fits the constraint, the easier it is to impose the constraint, and so κ\kappa will converge to zero, resulting in the unconstrained value for the pip_{i}.

The following lemma is helpful for developing the technical result sin the subsequent sections.

Lemma C.1.

Suppose that Assumption 1 holds. Then Hi(x;φ^(x))H_{i}(x;\hat{\varphi}(x)), defined in (2.14), is bounded on [t¯,t¯][\underline{t},\overline{t}] for each iUi\in U.

Proof.

The proof proceeds by the direct method. Observe that

|Hi(x;φ^(x))|φ^Ψ((Y¯AY¯A)s1(s1)!+(Y¯BY¯B)s1(s1)!+1)<+x[t¯,t¯],\displaystyle\left|H_{i}(x;\hat{\varphi}(x))\right|\leq\|\hat{\varphi}\|_{\Psi}\left(\frac{(\overline{Y}^{A}-\underline{Y}^{A})^{s-1}}{(s-1)!}+\frac{(\overline{Y}^{B}-\underline{Y}^{B})^{s-1}}{(s-1)!}+1\right)<+\infty\quad\forall x\in[\underline{t},\overline{t}],

where the last equality holds under Assumption 1, as it implies that φ^Ψ<+\|\hat{\varphi}\|_{\Psi}<+\infty and Y¯K,Y¯K\overline{Y}^{K},\underline{Y}^{K}\in\mathbb{R} for K=A,BK=A,B. ∎

C.2 Lemmas for Proof of Theorem 2

The following Lemmas derive the asymptotic distribution of {2(LURLR(x))/Deff^(x)ΠNAm,NBm}m=1\{2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\}_{m=1}^{\infty} for subsequences of sequences of {ΠNA,NB}NA,NB\{\Pi_{{N_{A}},{N_{B}}}\}_{N_{A},N_{B}}^{\infty} that drift on/to the boundary of the model of the null hypothesis H01H_{0}^{1}.

C.2.1 Lemma C.2

Lemma C.2.

Let {NA,NB0,NA,NB=1,2,}\left\{\mathcal{M}_{N_{A},N_{B}}^{0},\;N_{A},N_{B}=1,2,\ldots\right\}, 𝕎\mathbb{W} and α\alpha be the same as in Theorem 1. Let α(0,1)\alpha\in(0,1). For a sequence of finite populations {ΠNA,NB}NA,NB=1𝕎0\{\Pi_{N_{A},N_{B}}\}_{{N_{A},N_{B}}=1}^{\infty}\in\mathbb{W}_{0}, suppose there is a subsequence {ΠNAm,NBm}m=1\{\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\}_{m=1}^{\infty} such that ΠNAm,NBmNAm,NBm0m\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\in\partial\mathcal{M}_{{N_{A}}_{m},{N_{B}}_{m}}^{0}\;\forall m\in\mathbb{N}. For each mm\in\mathbb{N} let

xm\displaystyle x_{m} =min{x[t¯,t¯]:D¯NAms(x)=D¯NBms(x)}\displaystyle=\min\left\{x\in[\underline{t},\overline{t}]\;:\;\overline{D}_{{N_{A}}_{m}}^{s}(x)=\underline{D}_{{N_{B}}_{m}}^{s}(x)\right\}
=min{x[t¯,t¯]:θNAm,NBm(x;φNAm,NBm(x))=0}.\displaystyle=\min\left\{x\in[\underline{t},\overline{t}]\;:\;\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x;\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x)\right)=0\right\}.

Then, 2(LURLR(xm))/Deff^(xm)ΠNAm,NBmdχ12asm2(L_{UR}-L_{R}(x_{m}))/\widehat{\text{Deff}}(x_{m})\;\mid\;\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\operatorname*{\overset{d}{\longrightarrow}}\chi_{1}^{2}\ \text{as}\ m\rightarrow\infty.

Proof.

The proof proceeds using the direct method. For simplicity, we drop ΠNAm,NBm``\mid\;\Pi_{{N_{A}}_{m},{N_{B}}_{m}}". By the compactness of the set {x[t¯,t¯]:θNAm,NBm(x;φNAm,NBm(x))=0}\left\{x\in[\underline{t},\overline{t}]\;:\;\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x;\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x)\right)=0\right\}, xmx_{m} exists. Note that xmx_{m} is non-random and depends only on the sequence of finite populations. Using (C.12), notice that pip_{i} can be rewritten as:

pi\displaystyle p_{i} =1n[11+κHi(xm;φ^(xm))n]\displaystyle=\dfrac{1}{n}\left[\dfrac{1}{1+\dfrac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}}\right]
=1n[k=0(κHi(xm;φ^(xm))n)k]\displaystyle=\dfrac{1}{n}\left[\sum_{k=0}^{\infty}\left(-\frac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}\right)^{k}\right]
=1n[1κHi(xm;φ^(xm))n+(κHi(xm;φ^(xm))n)2]\displaystyle=\dfrac{1}{n}\left[1-\dfrac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}+\left(\dfrac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}\right)^{2}-\ldots\right] (C.13)

Then using (C.13), we substitute this into (C.10)

iUWiHi(xm;φ^(xm))(1n[1κHi(xm;φ^(xm))n+(κHi(xm;φ^(xm))n)2])=0\displaystyle\sum_{i\in U}W^{\prime}_{i}H_{i}(x_{m};\hat{\varphi}(x_{m}))\left(\dfrac{1}{n}\left[1-\dfrac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}+\left(\dfrac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}\right)^{2}-\ldots\right]\right)=0
H¯(xm;φ^(xm))κ(iUWin2Hi2(xm;φ^(xm)))+κ2(iUWin3Hi3(xm;φ^(xm)))=0,\displaystyle\bar{H}(x_{m};\hat{\varphi}(x_{m}))-\kappa\left(\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{2}}H^{2}_{i}(x_{m};\hat{\varphi}(x_{m}))\right)+\kappa^{2}\left(\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{3}}H^{3}_{i}(x_{m};\hat{\varphi}(x_{m}))\right)-\ldots=0, (C.14)

where H¯(xm;φ^(xm))=θ^(xm;φ^(xm))=iUWinHi(xm;φ^(xm))\bar{H}(x_{m};\hat{\varphi}(x_{m}))=\hat{\theta}(x_{m};\hat{\varphi}(x_{m}))=\sum_{i\in U}\frac{W^{\prime}_{i}}{n}H_{i}(x_{m};\hat{\varphi}(x_{m})). Equation (C.14) is equivalent to a convergent alternating series in κ\kappa, so κjiUWinj+1Hij+1(xm;φ^(xm))0\kappa^{j}\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{j+1}}H^{j+1}_{i}(x_{m};\hat{\varphi}(x_{m}))\rightarrow 0 as jj\rightarrow\infty. Therefore as mm\rightarrow\infty, ignoring terms beyond the first order, κ\kappa is asymptotically equivalent to:

κ=a[iUWin2Hi2(xm;φ^(xm))]1H¯(xm;φ^(xm)).\kappa\operatorname*{\overset{a}{=}}\left[\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{2}}H^{2}_{i}(x_{m};\hat{\varphi}(x_{m}))\right]^{-1}\bar{H}(x_{m};\hat{\varphi}(x_{m})). (C.15)

Let V(xm)=iUWin2Hi2(xm;φ^(xm))V(x_{m})=\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{2}}H^{2}_{i}(x_{m};\hat{\varphi}(x_{m})). Now using the result (C.12) for pip_{i} in 2(LURLR(xm))2(L_{UR}-L_{R}(x_{m})):

2(LURLR(xm))\displaystyle 2(L_{UR}-L_{R}(x_{m})) =2(iUWilog(1n)iUWilog(pi))\displaystyle=2\left(\sum_{i\in U}W^{\prime}_{i}\log\left(\frac{1}{n}\right)-\sum_{i\in U}W^{\prime}_{i}\log\left(p_{i}\right)\right)
=2iUWilog(1n1pi)\displaystyle=2\sum_{i\in U}W^{\prime}_{i}\log\left(\frac{1}{n}\frac{1}{p_{i}}\right)
=2iUWilog(1+κHi(xm;φ^(xm))n).\displaystyle=2\sum_{i\in U}W^{\prime}_{i}\log\left(1+\frac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}\right). (C.16)

Since Lemma C.1 establishes that Hi(xm;φ^(xm))H_{i}(x_{m};\hat{\varphi}(x_{m})) is uniformly bounded, and κ\kappa is tending to zero in probability and in design, we then use the standard expansion: log(1+u)=auu22for|u|<1\log(1+u)\operatorname*{\overset{a}{=}}u-\dfrac{u^{2}}{2}\quad\text{for}\ |u|<1, with u=κHi(xm;φ^(xm))nu=\frac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}.

2iUWilog(1+κHi(xm;φ^(xm))n)\displaystyle 2\sum_{i\in U}W^{\prime}_{i}\log\left(1+\frac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}\right) =a2iUWi[κHi(xm;φ^(xm))n12(κHi(xm;φ^(xm))n)2]\displaystyle\operatorname*{\overset{a}{=}}2\sum_{i\in U}W^{\prime}_{i}\left[\frac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}-\frac{1}{2}\left(\frac{\kappa H_{i}(x_{m};\hat{\varphi}(x_{m}))}{n}\right)^{2}\right]
=2κH¯(xm;φ^(xm))κ2V(xm)\displaystyle=2\kappa\bar{H}(x_{m};\hat{\varphi}(x_{m}))-\kappa^{2}V(x_{m})
then using (C.15)
=a2H¯2(xm;φ^(xm))V(xm)H¯2(xm;φ^(xm))V(xm)\displaystyle\operatorname*{\overset{a}{=}}\dfrac{2\bar{H}^{2}(x_{m};\hat{\varphi}(x_{m}))}{V(x_{m})}-\dfrac{\bar{H}^{2}(x_{m};\hat{\varphi}(x_{m}))}{V(x_{m})}
=H¯2(xm;φ^(xm))V(xm);\displaystyle=\dfrac{\bar{H}^{2}(x_{m};\hat{\varphi}(x_{m}))}{V(x_{m})}; (C.17)

therefore,

2(LURLR(xm))=a(θ^(xm;φ^(xm))Var(θ^(xm;φ^(xm))))2Var(θ^(xm;φ^(xm)))iUWin2Hi2(xm;φ^(xm)).2(L_{UR}-L_{R}(x_{m}))\operatorname*{\overset{a}{=}}\left(\dfrac{\hat{\theta}(x_{m};\hat{\varphi}(x_{m}))}{\sqrt{Var\left(\hat{\theta}(x_{m};\hat{\varphi}(x_{m}))\right)}}\right)^{2}\frac{Var\left(\hat{\theta}(x_{m};\hat{\varphi}(x_{m}))\right)}{\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{2}}H^{2}_{i}(x_{m};\hat{\varphi}(x_{m}))}.

Under the restriction of the boundary of the null hypothesis H01H_{0}^{1}:

iUWin2(Hi(xm;φ^(xm))H¯(xm;φ^(xm)))2=iUWin2Hi2(xm;φ^(xm))+oP(1),\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{2}}\left(H_{i}(x_{m};\hat{\varphi}(x_{m}))-\bar{H}(x_{m};\hat{\varphi}(x_{m}))\right)^{2}=\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{2}}H^{2}_{i}(x_{m};\hat{\varphi}(x_{m}))+o_{P}(1),

since H¯(xm;φ^(xm)P0\bar{H}(x_{m};\hat{\varphi}(x_{m})\operatorname*{\overset{P}{\longrightarrow}}0 as NAm,NBm{N_{A}}_{m},{N_{B}}_{m}\rightarrow\infty. Hence,

2(LURLR(xm))/Deff^(xm)\displaystyle 2(L_{UR}-L_{R}(x_{m}))/\widehat{\text{Deff}}(x_{m}) =a(θ^(xm;φ^(xm))Var(θ^(xm;φ^(xm))))2Deff(xm)Deff^(xm),\displaystyle\operatorname*{\overset{a}{=}}\left(\dfrac{\hat{\theta}(x_{m};\hat{\varphi}(x_{m}))}{\sqrt{Var\left(\hat{\theta}(x_{m};\hat{\varphi}(x_{m}))\right)}}\right)^{2}\frac{\text{Deff}(x_{m})}{\widehat{\text{Deff}}(x_{m})},
=(θ^(xm;φ^(xm))Var(θ^(xm;φ^(xm))))2Var(θ^(xm;φ^(xm)))Var^(θ^(xm;φ^(xm))),\displaystyle=\left(\dfrac{\hat{\theta}(x_{m};\hat{\varphi}(x_{m}))}{\sqrt{Var\left(\hat{\theta}(x_{m};\hat{\varphi}(x_{m}))\right)}}\right)^{2}\frac{Var\left(\hat{\theta}(x_{m};\hat{\varphi}(x_{m}))\right)}{\widehat{Var}\left(\hat{\theta}(x_{m};\hat{\varphi}(x_{m}))\right)},

and now using Conditions 4,5,6 and 7 of Assumption 2, and that

D¯NAms(xm)=D¯NBms(xm)θNAm,NBm(xm;φNAm,NBm(xm))=0,\overline{D}_{{N_{A}}_{m}}^{s}(x_{m})=\underline{D}_{{N_{B}}_{m}}^{s}(x_{m})\iff\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x_{m};\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x_{m})\right)=0,

we establish that along this subsequence:

2(LURLR(xm))/Deff^(xm)dχ12asm.2(L_{UR}-L_{R}(x_{m}))/\widehat{\text{Deff}}(x_{m})\operatorname*{\overset{d}{\longrightarrow}}\chi_{1}^{2}\ \text{as}\ m\rightarrow\infty.

C.2.2 Lemma C.3

Lemma C.3.

Let {NA,NB0,NA,NB=1,2,}\left\{\mathcal{M}_{N_{A},N_{B}}^{0},\;N_{A},N_{B}=1,2,\ldots\right\}, 𝕎0\mathbb{W}_{0} and α\alpha be the same as in Theorem 1. Let α(0,1)\alpha\in(0,1). For a sequence of finite populations {ΠNA,NB}NA,NB=1𝕎\{\Pi_{N_{A},N_{B}}\}_{{N_{A},N_{B}}=1}^{\infty}\in\mathbb{W}, suppose there is a subsequence {ΠNAm,NBm}m=1\{\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\}_{m=1}^{\infty} such that: ΠNAm,NBmint(NAm,NBm0)m\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\in int\left(\mathcal{M}_{{N_{A}}_{m},{N_{B}}_{m}}^{0}\right)\;\forall m\in\mathbb{N} and !xe[t¯,t¯]\exists!\ x_{e}\in[\underline{t},\overline{t}] such that C(xe)=0C(x_{e})=0 and C(x)=x[t¯,t¯]{xe}C(x)=-\infty\ \forall x\in[\underline{t},\overline{t}]\setminus\{x_{e}\}, where

C(x)\displaystyle C(x) =limm+D¯NAms(x)D¯NBms(x)Var(D¯^As(x)D¯^Bs(x)ΠNAm,NBm)ΠNAm,NBm\displaystyle=\lim_{m\rightarrow+\infty}\dfrac{\overline{D}_{{N_{A}}_{m}}^{s}(x)-\underline{D}_{{N_{B}}_{m}}^{s}(x)}{\sqrt{Var\left(\widehat{\overline{D}}_{A}^{s}(x)-\widehat{\underline{D}}_{B}^{s}(x)\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)}}\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}
=limm+θNAm,NBm(x;φNAm,NBm(x))Var(θ^(x;φ^(x))ΠNAm,NBm)ΠNAm,NBm\displaystyle=\lim_{m\rightarrow+\infty}\dfrac{\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x;\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x)\right)}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\right)}}\mid\Pi_{{N_{A}}_{m},{N_{B}}_{m}}

Then 2(LURLR(xe))/Deff^(xe)ΠNAm,NBmdχ12asm2(L_{UR}-L_{R}(x_{e}))/\widehat{\text{Deff}}(x_{e})\;\mid\;\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\operatorname*{\overset{d}{\longrightarrow}}\chi_{1}^{2}\ \text{as}\ m\rightarrow\infty.

Proof.

Following identical steps as in Lemma C.2, we have:

2(LURLR(xe))=a(θ^(xe;φ^(xe))Var(θ^(xe;φ^(xe))))2Var(θ^(xe;φ^(xe)))iUWin2Hi2(xe;φ^(xe))\displaystyle 2(L_{UR}-L_{R}(x_{e}))\operatorname*{\overset{a}{=}}\left(\dfrac{\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))}{\sqrt{Var\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}}\right)^{2}\frac{Var\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}{\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{2}}H^{2}_{i}(x_{e};\hat{\varphi}(x_{e}))}
=\displaystyle= (θ^(xe;φ^(xe))θNAm,NBm(xe;φNAm,NBm(xe))Var(θ^(xe;φ^(xe)))+θNAm,NBm(xe;φNAm,NBm(xe))Var(θ^(xe;φ^(xe))))2\displaystyle\left(\dfrac{\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))-\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x_{e};\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x_{e})\right)}{\sqrt{Var\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}}+\frac{\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x_{e};\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x_{e})\right)}{\sqrt{Var\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}}\right)^{2}
×Var(θ^(xe;φ^(xe)))iUWin2Hi2(xe;φ^(xe)).\displaystyle\quad\times\frac{Var\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}{\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{2}}H^{2}_{i}(x_{e};\hat{\varphi}(x_{e}))}.

Under the restriction of the boundary of the null hypothesis H01H_{0}^{1}:

iUWin2(Hi(xe;φ^(xe))H¯(xe;φ^(xe)))2=iUWin2Hi2(xe;φ^(xe)+oP(1),\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{2}}\left(H_{i}(x_{e};\hat{\varphi}(x_{e}))-\bar{H}(x_{e};\hat{\varphi}(x_{e}))\right)^{2}=\sum_{i\in U}\dfrac{W^{\prime}_{i}}{n^{2}}H^{2}_{i}(x_{e};\hat{\varphi}(x_{e})+o_{P}(1),

since H¯(xe;φ^(xe))=θ^(xe;φ^(xe))P0\bar{H}(x_{e};\hat{\varphi}(x_{e}))=\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\operatorname*{\overset{P}{\longrightarrow}}0 as NAm,NBm{N_{A}}_{m},{N_{B}}_{m}\rightarrow\infty. By definition of xex_{e}, the second term inside the brackets does not affect the limiting behaviour of the test statistic. Therefore, 2(LURLR(xe))/Deff^(xe)2(L_{UR}-L_{R}(x_{e}))/\widehat{\text{Deff}}(x_{e}) is asymptotically equivalent to

(θ^(xe;φ^(xe))θNAm,NBm(xe;φNAm,NBm(xe))Var(θ^(xe;φ^(xe)))+θNAm,NBm(xe;φNAm,NBm(xe))Var(θ^(xe;φ^(xe))))2Var(θ^(xe;φ^(xe)))Var^(θ^(xe;φ^(xe))),\displaystyle\left(\dfrac{\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))-\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x_{e};\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x_{e})\right)}{\sqrt{Var\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}}+\frac{\theta_{{N_{A}}_{m},{N_{B}}_{m}}\left(x_{e};\varphi_{{N_{A}}_{m},{N_{B}}_{m}}(x_{e})\right)}{\sqrt{Var\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}}\right)^{2}\,\frac{Var\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}{\widehat{Var}\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)},

and now applying Conditions 3 - 7 of Assumption 2 to the components of this expression yields

(θ^(xe;φ^(xe))Var(θ^(xe;φ^(xe))))2ΠNAm,NBmdχ12,\displaystyle\left(\dfrac{\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))}{\sqrt{Var\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}}\right)^{2}\;\mid\;\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\operatorname*{\overset{d}{\longrightarrow}}\chi_{1}^{2},
Var(θ^(xe;φ^(xe)))Var^(θ^(xe;φ^(xe)))ΠNAm,NBmP1.\displaystyle\frac{Var\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}{\widehat{Var}\left(\hat{\theta}(x_{e};\hat{\varphi}(x_{e}))\right)}\;\mid\;\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\operatorname*{\overset{P}{\longrightarrow}}1.

Therefore, along {ΠNAm,NBm}m=1\{\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\}_{m=1}^{\infty} it follows that

2(LURLR(xe))/Deff^(xe)ΠNAm,NBmdχ12asm.2(L_{UR}-L_{R}(x_{e}))/\widehat{\text{Deff}}(x_{e})\;\mid\;\Pi_{{N_{A}}_{m},{N_{B}}_{m}}\operatorname*{\overset{d}{\longrightarrow}}\chi_{1}^{2}\ \text{as}\ m\rightarrow\infty.

C.3 Lemmas for Proof of Theorem 3

The following two Lemmas describe the asymptotic behaviour of the test statistic {2(LURLR(x))/Deff^(x)ΠNA,NB}NA,NB=1\{2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\,\mid\,\Pi_{{N_{A}},{N_{B}}}\}_{N_{A},N_{B}=1}^{\infty} under the alternative hypothesis. The first Lemma focuses on sequences of finite populations that are uniformly bounded away from the boundary, corresponding to C(x)=C(x)=-\infty for all x[t¯,t¯]x\in[\underline{t},\overline{t}], where C()C(\cdot) is given by (4.5). The second Lemma focuses on sequences of finite populations that converge towards the boundary of the model of the null hypothesis H01H_{0}^{1} where there exists one or more x[t¯,t¯]x\in[\underline{t},\overline{t}] such that C(x)=0C(x)=0.

The following result is helpful in establishing these intermediate technical results.

Lemma C.4.

Given finite population ΠNA,NB\Pi_{N_{A},N_{B}}, under Assumption 3, for each x[t¯,t¯]x\in[\underline{t},\overline{t}] the design-effect satisfies

Deff(x)Pd1limNA,NB𝔼(nΠNA,NB)Var(θ^(x;φ^(x))ΠNA,NB)limNA,NB+SNA,NB,\displaystyle\text{Deff}(x)\operatorname*{\overset{P}{\longrightarrow}}d^{-1}\frac{\lim\limits_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}(n\mid\Pi_{N_{A},N_{B}})Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\Pi_{N_{A},N_{B}}\right)}{\lim\limits_{N_{A},N_{B}\rightarrow+\infty}S_{N_{A},N_{B}}}, (C.18)

and this limit is finite and positive.

Proof.

The proof proceed by the direct method. Using the representation of the design-effect, Deff(x)\text{Deff}(x) in (3.3), note that

Deff(x)\displaystyle\text{Deff}(x) =nVar(θ^(x;φ^(x))ΠNA,NB)iU(Wi/n)Hi2(x;φ^(x))\displaystyle=\frac{nVar\left(\hat{\theta}(x;\hat{\varphi}(x))\,\mid\,\Pi_{N_{A},N_{B}}\right)}{\sum_{i\in U}(W^{\prime}_{i}/n)H^{2}_{i}(x;\hat{\varphi}(x))} (C.19)
=nE[nΠNA,NB]E[nΠNA,NB]Var(θ^(x;φ^(x))ΠNA,NB)iU(Wi/n)Hi2(x;φ^(x)).\displaystyle=\frac{n}{E[n\mid\Pi_{N_{A},N_{B}}]}\frac{E[n\mid\Pi_{N_{A},N_{B}}]Var\left(\hat{\theta}(x;\hat{\varphi}(x))\,\mid\,\Pi_{N_{A},N_{B}}\right)}{\sum_{i\in U}(W_{i}/n)H^{2}_{i}(x;\hat{\varphi}(x))}. (C.20)

Now Condition 1 of Assumption 3 implies that nE[nΠNA,NB]Pd1++\frac{n}{E[n\mid\Pi_{N_{A},N_{B}}]}\operatorname*{\overset{P}{\longrightarrow}}d^{-1}\in\mathbb{R}_{++}. Furthermore, the denominator in this expression is a consistent estimator of SNA,NB(x)S_{N_{A},N_{B}}(x) in (3.4). Combining these two points with the implications of Conditions 2(i) and 2(ii) of Assumption 3 yield

Deff(x)Pd1limNA,NB𝔼(nΠNA,NB)Var(θ^(x;φ^(x))ΠNA,NB)limNA,NB+SNA,NB.\displaystyle\text{Deff}(x)\operatorname*{\overset{P}{\longrightarrow}}d^{-1}\frac{\lim\limits_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}(n\mid\Pi_{N_{A},N_{B}})Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\Pi_{N_{A},N_{B}}\right)}{\lim\limits_{N_{A},N_{B}\rightarrow+\infty}S_{N_{A},N_{B}}}. (C.21)

Since limNA,NB+SNA,NB\lim\limits_{N_{A},N_{B}\rightarrow+\infty}S_{N_{A},N_{B}} and limNA,NB𝔼(nΠNA,NB)Var(θ^(x;φ^(x))ΠNA,NB)\lim\limits_{N_{A},N_{B}\rightarrow\infty}\mathbbm{E}(n\mid\Pi_{N_{A},N_{B}})Var\left(\hat{\theta}(x;\hat{\varphi}(x))\mid\Pi_{N_{A},N_{B}}\right) are both positive and finite by Assumption 3, the probability limit of Deff(x)\text{Deff}(x) as NA,NB+N_{A},N_{B}\rightarrow+\infty is finite and positive. ∎

C.3.1 Lemma C.5

Lemma C.5.

Let 𝕎1(ε)\mathbb{W}_{1}(\varepsilon) be as in Definition 2 and C(x)C(x) be given by (4.5). Fix an ε>0\varepsilon>0 and x[t¯,t¯]x\in[\underline{t},\overline{t}]. For a sequence of finite populations {ΠNA,NB}NA,NB=1𝕎1(ε)\{\Pi_{N_{A},N_{B}}\}_{N_{A},N_{B}=1}^{\infty}\in\mathbb{W}_{1}(\varepsilon), then

2(LURLR(x))/Deff^(x)PasNA,NB.2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\operatorname*{\overset{P}{\longrightarrow}}\infty\ \text{as}\ N_{A},N_{B}\rightarrow\infty.
Proof.

We proceed via the direct method. Fix an x[t¯,t¯]x\in[\underline{t},\overline{t}] arbitrarily. Following identical steps in Lemma C.2 to obtain (C.16):

2(LURLR(x))=2iUWilog(1+κHi(x;φ^(x))n)2(L_{UR}-L_{R}(x))=2\sum_{i\in U}W_{i}\log\left(1+\frac{\kappa H_{i}(x;\hat{\varphi}(x))}{n}\right)

where κ\kappa is given by (C.15). By the duality of the of the optimisation problem (C.7), we have that:

2(LURLR(x))=maxξ[2iUWilog(1npi(ξ))]2(L_{UR}-L_{R}(x))=\max_{\xi\in\mathbb{R}}\left[2\sum_{i\in U}W^{\prime}_{i}\log\left(\frac{1}{np_{i}(\xi)}\right)\right] (C.22)

Where pi(ξ)p_{i}(\xi) is given by:

pi(ξ)=1n+ξHi(x;φ^(x))p_{i}(\xi)=\dfrac{1}{n+\xi H_{i}(x;\hat{\varphi}(x))}

Thus, by applying duality, we have that for any arbitrary ξ\xi\in\mathbb{R}:

2(LURLR(x))2iUWilog(1+ξHi(x;φ^(x))n)2(L_{UR}-L_{R}(x))\geq 2\sum_{i\in U}W^{\prime}_{i}\log\left(1+\frac{\xi H_{i}(x;\hat{\varphi}(x))}{n}\right) (C.23)

We now choose ξ\xi dependent on the sequence of finite populations such that ξ=oP(n)\xi=o_{P}(n) as NA,NBN_{A},N_{B}\rightarrow\infty, that is:

ξnΠNA,NBP0asNA,NB\frac{\xi}{n}\mid\,\Pi_{N_{A},N_{B}}\operatorname*{\overset{P}{\longrightarrow}}0\quad\text{as}\ N_{A},N_{B}\rightarrow\infty

This property on ξ\xi is necessary to ensure that the expansion log(1+u)=auu22for|u|<1\log(1+u)\operatorname*{\overset{a}{=}}u-\dfrac{u^{2}}{2}\ \text{for}\ |u|<1, where u=ξHi(x;φ^(xm))nu=\dfrac{\xi H_{i}(x;\hat{\varphi}(x_{m}))}{n}, is valid. Note that by Lemma  C.1, Hi(x;φ^(x))H_{i}(x;\hat{\varphi}(x)) is uniformly bounded on [t¯,t¯][\underline{t},\overline{t}]. Setting ξ\xi as:

ξ=1Var(θ^(x;φ^(x))ΠNA,NB)\xi=\frac{-1}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\,\mid\,\Pi_{N_{A},N_{B}}\right)}} (C.24)

Then using the second order logarithm expansion on (C.23) and substituting (C.24) for ξ\xi we get:

2(LURLR(x))\displaystyle 2(L_{UR}-L_{R}(x)) 2iUWilog(1+ξHi(x;φ^(x))n)\displaystyle\geq 2\sum_{i\in U}W^{\prime}_{i}\log\left(1+\frac{\xi H_{i}(x;\hat{\varphi}(x))}{n}\right)
=a2iUWi[ξHi(x;φ^(x))n12(ξHi(x;φ^(x))n)2]\displaystyle\operatorname*{\overset{a}{=}}2\sum_{i\in U}W^{\prime}_{i}\left[\frac{\xi H_{i}(x;\hat{\varphi}(x))}{n}-\frac{1}{2}\left(\frac{\xi H_{i}(x;\hat{\varphi}(x))}{n}\right)^{2}\right]
=2θ^(x;φ^(x))Var(θ^(x;φ^(x))ΠNA,NB)1Deff(x)\displaystyle=-2\frac{\hat{\theta}(x;\hat{\varphi}(x))}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\,\mid\,\Pi_{N_{A},N_{B}}\right)}}-\frac{1}{\text{Deff}(x)}
=2θ^(x;φ^(x))θNA,NB(x;φNA,NB(x))Var(θ^(x;φ^(x))ΠNA,NB)\displaystyle=-2\frac{\hat{\theta}(x;\hat{\varphi}(x))-\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\,\mid\,\Pi_{N_{A},N_{B}}\right)}}
2θNA,NB(x;φNA,NB(x))Var(θ^(x;φ^(x))ΠNA,NB)1Deff(x)\displaystyle\quad-2\frac{\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\,\mid\,\Pi_{N_{A},N_{B}}\right)}}-\frac{1}{\text{Deff}(x)} (C.25)

Hence, asymptotically,

2(LURLR(x))Deff^(x)\displaystyle\frac{2(L_{UR}-L_{R}(x))}{\widehat{\text{Deff}}(x)} 2Deff^(x)[θ^(x;φ^(x))θNA,NB(x;φNA,NB(x))Var(θ^(x;φ^(x))ΠNA,NB)]\displaystyle\geq\frac{-2}{\widehat{\text{Deff}}(x)}\left[\frac{\hat{\theta}(x;\hat{\varphi}(x))-\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\,\mid\,\Pi_{N_{A},N_{B}}\right)}}\right]
2Deff^(x)[θNA,NB(x;φNA,NB(x))Var(θ^(x;φ^(x))ΠNA,NB)]1Deff^(x)Deff(x)\displaystyle\quad-\frac{2}{\widehat{\text{Deff}}(x)}\left[\frac{\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\,\mid\,\Pi_{N_{A},N_{B}}\right)}}\right]-\frac{1}{\widehat{\text{Deff}}(x)\,\text{Deff}(x)} (C.26)

Conditions 4 and 5 of Assumption 2 and Lemma C.4 imply the first term on the right side in (C.26) converges in distribution to

N(0,4limNA,NB+Deff(x)2).N\left(0,\frac{4}{\lim_{N_{A},N_{B}\rightarrow+\infty}\text{Deff}(x)^{2}}\right).

The second term on the right side in (C.26) converges to 2C(x)/limNA,NB+Deff(x)-2C(x)/\lim_{N_{A},N_{B}\rightarrow+\infty}\text{Deff}(x). Since the denominator is finite and positive, this limit is determined by the value of C(x)C(x). As C(x)=C(x)=-\infty, the limit of the second term diverges to \infty. Finally, the limit of third term on the right side in (C.26) is 1/limNA,NB+Deff(x)2++1/\lim_{N_{A},N_{B}\rightarrow+\infty}\text{Deff}(x)^{2}\in\mathbb{R}_{++} by Condition 5 of Assumption 2 and Lemma C.4.

Thus, as a result we have that 2(LURLR(x))/Deff^(x)P2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\operatorname*{\overset{P}{\longrightarrow}}\infty as NA,NBN_{A},N_{B}\rightarrow\infty. We now demonstrate this choice of ξ\xi satisfies ξ=oP(n)\xi=o_{P}(n). Note that:

|ξn|\displaystyle\left|\frac{\xi}{n}\right| =1nVar(θ^(x;φ^(x))ΠNA,NB)\displaystyle=\frac{1}{n\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\,\mid\,\Pi_{N_{A},N_{B}}\right)}}
=𝔼(nΠNA,NB)n1n𝔼(nΠNA,NB)Var(θ^(x;φ^(x))ΠNA,NB)\displaystyle=\frac{\sqrt{\dfrac{\mathbbm{E}(n\mid\Pi_{N_{A},N_{B}})}{n}}\sqrt{\dfrac{1}{n}}}{\sqrt{\mathbbm{E}(n\mid\Pi_{N_{A},N_{B}})Var\left(\hat{\theta}(x;\hat{\varphi}(x))\,\mid\,\Pi_{N_{A},N_{B}}\right)}}

Then using Conditions 1 and 2 of Assumption 3, we find the limiting behaviour is determined by 1n\frac{1}{\sqrt{n}}. Therefore, since nPn\operatorname*{\overset{P}{\longrightarrow}}\infty as NA,NBN_{A},N_{B}\rightarrow\infty (i.e., implied by Condition 1 of Assumption 2), we have that ξ=oP(n)\xi=o_{P}(n). ∎

C.3.2 Lemma C.6

Lemma C.6.

Let 𝕎1(ε)\mathbb{W}_{1}(\varepsilon) be defined the same as in Definition 2 and C(x)C(x) is given by (4.5). For a sequence of finite populations {ΠNA,NB}NA,NB=1𝕎1(0)\{\Pi_{N_{A}},{N_{B}}\}_{N_{A},N_{B}=1}^{\infty}\in\mathbb{W}_{1}(0) define the set X0={x[t¯,t¯]:C(x)=0}X_{0}=\{x\in[\underline{t},\overline{t}]:C(x)=0\}. If X0X_{0}\neq\emptyset then for xX0x\in X_{0}:

2(LURLR(x))/Deff^(x)ΠNA,NBdχ12asNA,NB.2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\mid\Pi_{N_{A},N_{B}}\operatorname*{\overset{d}{\longrightarrow}}\chi_{1}^{2}\ \text{as}\ N_{A},N_{B}\rightarrow\infty.
Proof.

The asymptotic power of the test will be lowest for sequences of finite populations that converge to the boundary of the model of the alternative hypothesis H11H_{1}^{1}. This will be where for every finite NA,NBN_{A},N_{B} the finite population is in NA,NB1\mathcal{M}_{N_{A},N_{B}}^{1} but converges to the model of the null hypothesis H01H_{0}^{1} in the limit. That is, for one or more x[t¯,t¯]x\in[\underline{t},\overline{t}] we will have C(x)=0C(x)=0. Let X0X_{0} be the set {x[t¯,t¯]:C(x)=0}\{x\in[\underline{t},\overline{t}]:C(x)=0\}. Fix an xX0x\in X_{0}. Following identical steps as in Lemma C.2, we obtain:

2(LURLR(x))=a\displaystyle 2(L_{UR}-L_{R}(x))\operatorname*{\overset{a}{=}} (θ^(x;φ^(x))Var(θ^(x;φ^(x))))2Var(θ^(x;φ^(x)))iUWi1n2Hi2(x;φ^(x))\displaystyle\left(\frac{\hat{\theta}(x;\hat{\varphi}(x))}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\right)}}\right)^{2}\frac{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\right)}{\sum_{i\in U}W^{\prime}_{i}\dfrac{1}{n^{2}}H^{2}_{i}(x;\hat{\varphi}(x))}
=\displaystyle= (θ^(x;φ^(x))θNA,NB(x;φNA,NB(x))Var(θ^(x;φ^(x)))+θNA,NB(x;φNA,NB(x))Var(θ^(x;φ^(x))))2Deff(x)\displaystyle\left(\frac{\hat{\theta}(x;\hat{\varphi}(x))-\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\right)}}+\frac{\theta_{N_{A},N_{B}}(x;\varphi_{N_{A},N_{B}}(x))}{\sqrt{Var\left(\hat{\theta}(x;\hat{\varphi}(x))\right)}}\right)^{2}\,\text{Deff}(x)

Using Conditions 4 and 5 of Assumption 2 and that C(x)=0C(x)=0 for xX0x\in X_{0},

2(LURLR(x))/Deff^(x)d𝔾2(x)asNA,NB.2(L_{UR}-L_{R}(x))/\widehat{\text{Deff}}(x)\operatorname*{\overset{d}{\longrightarrow}}\mathbb{G}^{2}(x)\ \text{as}\ N_{A},N_{B}\rightarrow\infty.

For each xx, the random variable 𝔾(x)\mathbb{G}(x) is distributed as standard normal; therefore, 𝔾2(x)χ12\mathbb{G}^{2}(x)\sim\chi_{1}^{2}. ∎

Appendix D Technical Results for the Examples in Section 2.2

This section presents the identified sets of DNKs(x)D^{s}_{N_{K}}(x) for each x[t¯,t¯]x\in[\underline{t},\overline{t}] and K=A,BK=A,B, associated with the Examples in Section 2.2. These sets are characterized in terms of sharp bounds

D¯NKs(x)DNKs(x)D¯NAs(x)x[t¯,t¯],\underline{D}_{N_{K}}^{s}(x)\leq D^{s}_{N_{K}}(x)\leq\overline{D}_{N_{A}}^{s}(x)\quad x\in[\underline{t},\overline{t}],

and the results of this section describe the bounds under the informational setups of the examples.

D.1 Example 1: Worst-Case Bounds

Proposition D.1.

For each x[t¯,t¯]x\in[\underline{t},\overline{t}] and ss\in\mathbb{N}, the worst-case bounds are

D¯NAs(x)\displaystyle\underline{D}_{N_{A}}^{s}(x) =𝔼FA(x|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]]δ11\displaystyle=\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{11}
+𝔼FA(x|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10,\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10},
D¯NAs(x)\displaystyle\overline{D}_{N_{A}}^{s}(x) =D¯NAs(x)+(xY¯A)s1(s1)!δ00,\displaystyle=\underline{D}_{N_{A}}^{s}(x)+\frac{(x-\underline{Y}^{A})^{s-1}}{(s-1)!}\,\delta_{00},
D¯NBs(x)\displaystyle\underline{D}_{N_{B}}^{s}(x) =𝔼FB(x|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]]δ11,\displaystyle=\mathbbm{E}_{F_{B}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,\delta_{11},
D¯NBs(x)\displaystyle\overline{D}_{N_{B}}^{s}(x) =D¯NBs(x)+(xY¯B)s1(s1)!(δ00+δ10),\displaystyle=\underline{D}_{N_{B}}^{s}(x)+\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}\,(\delta_{00}+\delta_{10}),

where Y¯K=inf𝒳K\underline{Y}^{K}=\inf\mathcal{X}_{K}, for K=A,BK=A,B.

Proof.

The proof proceeds by the direct method. Let K=AK=A, and fix ss\in\mathbb{N} and x[t¯,t¯]x\in[\underline{t},\overline{t}]. The law of total probability expansion of DNAs(x)D_{N_{A}}^{s}(x), given by (2.4), is

𝔼FA(|ZA=ZB=1)\displaystyle\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)} [(xYA)s1(s1)! 1[YAx]]δ11+𝔼FA(|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10\displaystyle\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{11}+\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}
+𝔼FA(|ZA=ZB=0)[(xYA)s1(s1)! 1[YAx]]δ00.\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{00}.

Note that 𝔼FA(|ZA=ZB=0)[(xYA)s1(s1)! 1[YAx]]\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right] is not identified, but can be bounded from below and above by 0 and (xY¯A)s1(s1)!\frac{(x-\underline{Y}^{A})^{s-1}}{(s-1)!}, respectively. These bounds on that conditional expectation imply the desired bounds on DNAs(x)D_{N_{A}}^{s}(x) by direct substitution. Now since s+s\in\mathbb{Z}_{+} and x[t¯,t¯]x\in[\underline{t},\overline{t}] were arbitrary, the above bounds hold for each ss\in\mathbb{N} and x[t¯,t¯]x\in[\underline{t},\overline{t}].

Let K=BK=B, and fix ss\in\mathbb{N} and x[t¯,t¯]x\in[\underline{t},\overline{t}]. The law of total probability expansion of DNBs(x)D_{N_{B}}^{s}(x), given by (2.4), is

𝔼FB(|ZA=ZB=1)\displaystyle\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)} [(xYB)s1(s1)! 1[YBx]]δ11+𝔼FB(|ZA=1,ZB=0)[(xYB)s1(s1)! 1[YBx]]δ10\displaystyle\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,\delta_{11}+\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,\delta_{10}
+𝔼FB(|ZA=ZB=0)[(xYB)s1(s1)! 1[YBx]]δ00.\displaystyle\qquad+\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=0\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,\delta_{00}.

Note that 𝔼FB(|ZA=1,ZB=0)[(xYB)s1(s1)! 1[YBx]]\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right] and 𝔼FB(|ZA=ZB=0)[(xYB)s1(s1)! 1[YBx]]\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=0\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right] not identified, but are bounded from below by 0 and from above by (xY¯B)s1(s1)!\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}. These bounds on that conditional expectation imply the desired bounds on DNBs(x)D_{N_{B}}^{s}(x) by direct substitution. Now since ss\in\mathbb{N} and x[t¯,t¯]x\in[\underline{t},\overline{t}] were arbitrary, the above bounds hold for each ss\in\mathbb{N} and x[t¯,t¯]x\in[\underline{t},\overline{t}]. ∎

D.2 Example 2

Recall that the assumption of MCAR for unit nonresponse means

FK(x|ZA=ZB=1)=FK(x|ZA=ZB=0)x𝒳K\displaystyle F_{K}\left(x|Z^{A}=Z^{B}=1\right)=F_{K}\left(x|Z^{A}=Z^{B}=0\right)\quad\forall x\in\mathcal{X}_{K} (D.1)

holds, for K=A,BK=A,B, and that this condition does not imply any restrictions on wave nonrepsonse. We have the following result.

Proposition D.2.

Suppose that (D.1) holds. For each x[t¯,t¯]x\in[\underline{t},\overline{t}] and ss\in\mathbb{N}, the corresponding bounds are

D¯NAs(x)\displaystyle\underline{D}_{N_{A}}^{s}(x) =𝔼FA(x|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]](δ11+δ00)\displaystyle=\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,(\delta_{11}+\delta_{00})
+𝔼FA(x|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}
D¯NAs(x)\displaystyle\overline{D}_{N_{A}}^{s}(x) =D¯NAs(x),\displaystyle=\underline{D}_{N_{A}}^{s}(x),
D¯NBs(x)\displaystyle\underline{D}_{N_{B}}^{s}(x) =𝔼FB(x|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]](δ11+δ00),\displaystyle=\mathbbm{E}_{F_{B}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,(\delta_{11}+\delta_{00}),
D¯NBs(x)\displaystyle\overline{D}_{N_{B}}^{s}(x) =D¯NBs(x)+(xY¯B)s1(s1)!δ10,\displaystyle=\underline{D}_{N_{B}}^{s}(x)+\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}\,\delta_{10},

where Y¯K=inf𝒳K\underline{Y}^{K}=\inf\mathcal{X}_{K}, for K=A,BK=A,B.

Proof.

The proof proceeds by the direct method. Let K=AK=A, and fix ss\in\mathbb{N} and x[t¯,t¯]x\in[\underline{t},\overline{t}]. The law of total probability expansion of DNAs(x)D_{N_{A}}^{s}(x), given by (2.4), is

𝔼FA(|ZA=ZB=1)\displaystyle\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)} [(xYA)s1(s1)! 1[YAx]]δ11+𝔼FA(|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10\displaystyle\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{11}+\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}
+𝔼FA(|ZA=ZB=0)[(xYA)s1(s1)! 1[YAx]]δ00.\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{00}.

Condition (D.1) implies

𝔼FA(|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]]=𝔼FA(|ZA=ZB=0)[(xYA)s1(s1)! 1[YAx]],\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]=\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right],

holds, for each x𝒳Ax\in\mathcal{X}_{A}. Hence, DNAsD_{N_{A}}^{s} is point-identified and given by

DNAs(x)\displaystyle D_{N_{A}}^{s}(x) =𝔼FA(x|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]](δ11+δ00)\displaystyle=\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,(\delta_{11}+\delta_{00})
+𝔼FA(x|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}

for each x𝒳Ax\in\mathcal{X}_{A}, implying the desired result.

Let K=BK=B, and fix ss\in\mathbb{N} and x[t¯,t¯]x\in[\underline{t},\overline{t}]. The law of total probability expansion of DNBs(x)D_{N_{B}}^{s}(x), given by (2.4), is

𝔼FB(|ZA=ZB=1)\displaystyle\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)} [(xYB)s1(s1)! 1[YBx]]δ11+𝔼FB(|ZA=1,ZB=0)[(xYB)s1(s1)! 1[YBx]]δ10\displaystyle\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,\delta_{11}+\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,\delta_{10}
+𝔼FB(|ZA=ZB=0)[(xYB)s1(s1)! 1[YBx]]δ00.\displaystyle\qquad+\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=0\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,\delta_{00}.

Condition (D.1) implies

𝔼FB(|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]]=𝔼FB(|ZA=ZB=0)[(xYB)s1(s1)! 1[YAx]],\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]=\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=0\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right],

holds, for each x𝒳Bx\in\mathcal{X}_{B}. Consequently, only 𝔼FB(|ZA=1,ZB=0)[(xYB)s1(s1)! 1[YBx]]\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right] in this expansion is not identified, but it is bounded from below by 0 and from above by (xY¯B)s1(s1)!\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}. These bounds on that conditional expectation imply the desired bounds on DNBs(x)D_{N_{B}}^{s}(x) by direct substitution. Now since ss\in\mathbb{N} and x[t¯,t¯]x\in[\underline{t},\overline{t}] were arbitrary, the above bounds hold for each ss\in\mathbb{N} and x[t¯,t¯]x\in[\underline{t},\overline{t}]. ∎

D.3 Example 3: Neighborhood of MCAR

Recall that the neighborhood condition in Example 3 specifies the following system of inequalities for the conditional probabilities Prob(ZA=ZB=0|YAx)\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{A}\leq x\right), Prob(ZA=ZB=0|YBx)\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{B}\leq x\right), and
Prob(ZA=1,ZB=0|YBx)\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right):

δ00L00K(x)\displaystyle\delta_{00}\,L^{K}_{00}(x) Prob(ZA=ZB=0|YKx)U00K(x)δ00,K=A,B,and\displaystyle\leq\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{K}\leq x\right)\leq U^{K}_{00}(x)\,\delta_{00},\quad K=A,B,\quad\text{and} (D.2)
δ10L10(x)\displaystyle\delta_{10}\,L_{10}(x) Prob(ZA=1,ZB=0|YBx)U10(x)δ10,\displaystyle\leq\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right)\leq U_{10}(x)\,\delta_{10}, (D.3)

where L00AL^{A}_{00}, U00AU^{A}_{00}, L00BL^{B}_{00}, U00BU^{B}_{00}, L10L_{10}, and U10U_{10} are CDFs that are predesignated by the practitioner which satisfy L00K()U00K()L^{K}_{00}(\cdot)\leq U^{K}_{00}(\cdot), for K=A,BK=A,B, and L10U10L_{10}\leq U_{10}.

Let

G¯A(x)\displaystyle\overline{G}_{A}(x) =1δ001U00A(x)δ00andG¯A(x)=1δ001L00A(x)δ00x𝒳A,\displaystyle=\frac{1-\delta_{00}}{1-U^{A}_{00}(x)\delta_{00}}\quad\text{and}\quad\underline{G}_{A}(x)=\frac{1-\delta_{00}}{1-L^{A}_{00}(x)\delta_{00}}\quad\forall x\in\mathcal{X}_{A},
G¯B(x)\displaystyle\overline{G}_{B}(x) =δ111U00B(x)δ00U10B(x)δ10andG¯B(x)=δ111L00B(x)δ00L10(x)δ10x𝒳B,\displaystyle=\frac{\delta_{11}}{1-U^{B}_{00}(x)\delta_{00}-U^{B}_{10}(x)\delta_{10}}\quad\text{and}\quad\underline{G}_{B}(x)=\frac{\delta_{11}}{1-L^{B}_{00}(x)\delta_{00}-L_{10}(x)\delta_{10}}\quad\forall x\in\mathcal{X}_{B},

which are CDFs. Hence, we can define the dominance functions recursively: for G{G¯A,G¯A,G¯B,G¯B}G\in\{\overline{G}_{A},\underline{G}_{A},\overline{G}_{B},\underline{G}_{B}\}, these functions are DG1(x)=G(x)D_{G}^{1}(x)=G(x) and DGs(x)=xDGs1(u)duD^{s}_{G}(x)=\int_{-\infty}^{x}D^{s-1}_{G}(u)\,\text{d}u for s=2,3,4,s=2,3,4,\ldots. Finally, for we also introduce the following recursively defined functions defined on 2\mathbb{R}^{2}: R0(y,x)=𝟙[yx]R_{0}(y,x)=\mathbbm{1}[y\leq x], Rj(y,x)=xRj1(y,u)𝑑uR_{j}(y,x)=\int_{-\infty}^{x}R_{j-1}(y,u)\,du for j=1,2,j=1,2,\ldots.

Proposition D.3.

Suppose that Prob(ZA=ZB=0|YAx)\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{A}\leq x\right), Prob(ZA=ZB=0|YBx)\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{B}\leq x\right), and
Prob(ZA=1,ZB=0|YBx)\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right) satisfy the inequalities (D.2) and (D.3). For each x[t¯,t¯]x\in[\underline{t},\overline{t}] and ss\in\mathbb{N}, the corresponding bounds on the dominance functions are

D¯NAs(x)\displaystyle\underline{D}_{N_{A}}^{s}(x) =(δ111δ00FA(x|ZA=ZB=1)+δ101δ00FA(x|ZA=1,ZB=0))DG¯As(x)\displaystyle=\left(\frac{\delta_{11}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=Z^{B}=1\right)+\frac{\delta_{10}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\right)D^{s}_{\underline{G}_{A}}(x)
𝟙[s>1]δ111δ00j=0s2𝔼FA(|ZA=ZB=1)[DG¯As(YA)Rj(YA,x)]\displaystyle\qquad-\mathbbm{1}[s>1]\frac{\delta_{11}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\underline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right]
𝟙[s>1]δ101δ00j=0s2𝔼FA(|ZA=1,ZB=0)[DG¯As(YA)Rj(YA,x)]\displaystyle\qquad-\mathbbm{1}[s>1]\frac{\delta_{10}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{s}_{\underline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right]
D¯NAs(x)\displaystyle\overline{D}_{N_{A}}^{s}(x) =(δ111δ00FA(x|ZA=ZB=1)+δ101δ00FA(x|ZA=1,ZB=0))DG¯As(x)\displaystyle=\left(\frac{\delta_{11}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=Z^{B}=1\right)+\frac{\delta_{10}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\right)D^{s}_{\overline{G}_{A}}(x)
𝟙[s>1]δ111δ00j=0s2𝔼FA(|ZA=ZB=1)[DG¯As(YA)Rj(YA,x)]\displaystyle\qquad-\mathbbm{1}[s>1]\frac{\delta_{11}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\overline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right]
𝟙[s>1]δ101δ00j=0s2𝔼FA(|ZA=1,ZB=0)[DG¯As(YA)Rj(YA,x)]\displaystyle\qquad-\mathbbm{1}[s>1]\frac{\delta_{10}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{s}_{\overline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right]
D¯NBs(x)\displaystyle\underline{D}_{N_{B}}^{s}(x) =FB(x|ZA=ZB=1)DG¯Bs(x)𝟙[s>1]j=0s2𝔼FB(|ZA=ZB=1)[DG¯Bs(YB)Rj(YB,x)]\displaystyle=F_{B}\left(x|Z^{A}=Z^{B}=1\right)\,D^{s}_{\underline{G}_{B}}(x)-\mathbbm{1}[s>1]\sum_{j=0}^{s-2}\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\underline{G}_{B}}(Y^{B})\,R_{j}(Y^{B},x)\right]
D¯NBs(x)\displaystyle\overline{D}_{N_{B}}^{s}(x) =FB(x|ZA=ZB=1)DG¯Bs(x)𝟙[s>1]j=0s2𝔼FB(|ZA=ZB=1)[DG¯Bs(YB)Rj(YB,x)].\displaystyle=F_{B}\left(x|Z^{A}=Z^{B}=1\right)\,D^{s}_{\overline{G}_{B}}(x)-\mathbbm{1}[s>1]\sum_{j=0}^{s-2}\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\overline{G}_{B}}(Y^{B})\,R_{j}(Y^{B},x)\right].
Proof.

The proof proceeds by the direct method. We start with population AA. For s=1s=1 and x𝒳Ax\in\mathcal{X}_{A}, the Law of Total Probability applied to FA(x)F_{A}(x) yields

FA(x)=FA(x|ZA=ZB=1)δ11+FA(x|ZA=1,ZB=0)δ10+FA(x|ZA=ZB=0)δ00.\displaystyle F_{A}(x)=F_{A}\left(x|Z^{A}=Z^{B}=1\right)\,\delta_{11}+F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\,\delta_{10}+F_{A}\left(x|Z^{A}=Z^{B}=0\right)\,\delta_{00}.

Next, apply Bayes’ Theorem to FA(x|ZA=ZB=0)F_{A}\left(x|Z^{A}=Z^{B}=0\right) to express it in terms of Prob(ZA=ZB=0|YAx)\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{A}\leq x\right), substitute this resulting expression into the above representation of FA(x)F_{A}(x), and solving for FA(x)F_{A}(x), yields

FA(x)\displaystyle F_{A}(x) =FA(x|ZA=ZB=1)1Prob(ZA=ZB=0|YAx)δ11+FA(x|ZA=1,ZB=0)1Prob(ZA=ZB=0|YAx)δ10.\displaystyle=\frac{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}{1-\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{A}\leq x\right)}\,\delta_{11}+\frac{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}{1-\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{A}\leq x\right)}\,\delta_{10}.

As DNA1(x)=FA(x)D_{N_{A}}^{1}(x)=F_{A}(x), we substitute out Prob(ZA=ZB=0|YAx)\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{A}\leq x\right) in the above expression using the inequalities (D.2) to obtain

D¯NA1(x)\displaystyle\underline{D}_{N_{A}}^{1}(x) =(δ111δ00FA(x|ZA=ZB=1)+δ101δ00FA(x|ZA=1,ZB=0))DG¯A1(x)and\displaystyle=\left(\frac{\delta_{11}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=Z^{B}=1\right)+\frac{\delta_{10}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\right)D^{1}_{\underline{G}_{A}}(x)\quad\text{and}
D¯NA1(x)\displaystyle\overline{D}_{N_{A}}^{1}(x) =(δ111δ00FA(x|ZA=ZB=1)+δ101δ00FA(x|ZA=1,ZB=0))DG¯A1(x).\displaystyle=\left(\frac{\delta_{11}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=Z^{B}=1\right)+\frac{\delta_{10}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\right)D^{1}_{\overline{G}_{A}}(x).

As x𝒳Ax\in\mathcal{X}_{A} was arbitrary, the above derivation holds for each x𝒳Ax\in\mathcal{X}_{A}.

Now we focus on s=2s=2. Fix x𝒳Ax\in\mathcal{X}_{A}. Since D¯NA1(x)DNA1(x)D¯NA1(x)\underline{D}_{N_{A}}^{1}(x)\leq D_{N_{A}}^{1}(x)\leq\overline{D}_{N_{A}}^{1}(x) and DNA2(x)=xDNA1(u)𝑑uD_{N_{A}}^{2}(x)=\int_{-\infty}^{x}D_{N_{A}}^{1}(u)\,du, we can integrate all sides to obtain

D¯NA2(x)=xD¯NA1(u)𝑑uDNA2(x)xD¯NA1(u)𝑑u=D¯NA2(x).\displaystyle\underline{D}_{N_{A}}^{2}(x)=\int_{-\infty}^{x}\underline{D}_{N_{A}}^{1}(u)\,du\leq D_{N_{A}}^{2}(x)\leq\int_{-\infty}^{x}\overline{D}_{N_{A}}^{1}(u)\,du=\overline{D}_{N_{A}}^{2}(x).

Since D¯NA1\underline{D}_{N_{A}}^{1} and D¯NA1\overline{D}_{N_{A}}^{1} are mixtures of products of CDFs, we can use integration by parts to obtain expressions for D¯NA2(x)\underline{D}_{N_{A}}^{2}(x) and D¯NA2(x)\overline{D}_{N_{A}}^{2}(x), given by

{FA(x|ZA=ZB=1)xDG¯A1(u)𝑑uxuG¯A(u)𝑑u𝑑FA(u|ZA=ZB=1)}δ111δ00\displaystyle\left\{F_{A}\left(x|Z^{A}=Z^{B}=1\right)\,\int_{-\infty}^{x}D^{1}_{\underline{G}_{A}}(u)\,du-\int_{-\infty}^{x}\int_{-\infty}^{u}\underline{G}_{A}(u^{\prime})\,du^{\prime}dF_{A}\left(u|Z^{A}=Z^{B}=1\right)\right\}\frac{\delta_{11}}{1-\delta_{00}}
+{FA(x|ZA=1,ZB=0)xDG¯A1(u)𝑑uxuG¯A(u)𝑑u𝑑FA(u|ZA=0,ZB=1)}δ101δ00,\displaystyle+\left\{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\,\int_{-\infty}^{x}D^{1}_{\underline{G}_{A}}(u)\,du-\int_{-\infty}^{x}\int_{-\infty}^{u}\underline{G}_{A}(u^{\prime})\,du^{\prime}dF_{A}\left(u|Z^{A}=0,Z^{B}=1\right)\right\}\frac{\delta_{10}}{1-\delta_{00}},

and

{FA(x|ZA=ZB=1)xDG¯A1(u)𝑑uxuG¯A(u)𝑑u𝑑FA(u|ZA=ZB=1)}δ111δ00\displaystyle\left\{F_{A}\left(x|Z^{A}=Z^{B}=1\right)\,\int_{-\infty}^{x}D^{1}_{\overline{G}_{A}}(u)\,du-\int_{-\infty}^{x}\int_{-\infty}^{u}\overline{G}_{A}(u^{\prime})\,du^{\prime}dF_{A}\left(u|Z^{A}=Z^{B}=1\right)\right\}\frac{\delta_{11}}{1-\delta_{00}}
+{FA(x|ZA=1,ZB=0)xDG¯A1(u)𝑑uxuG¯A(u)𝑑u𝑑FA(u|ZA=0,ZB=1)}δ101δ00,\displaystyle+\left\{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\,\int_{-\infty}^{x}D^{1}_{\overline{G}_{A}}(u)\,du-\int_{-\infty}^{x}\int_{-\infty}^{u}\overline{G}_{A}(u^{\prime})\,du^{\prime}dF_{A}\left(u|Z^{A}=0,Z^{B}=1\right)\right\}\frac{\delta_{10}}{1-\delta_{00}},

respectively. Now recognizing that DG¯A2(x)=xDG¯A1(u)𝑑uD^{2}_{\underline{G}_{A}}(x)=\int_{-\infty}^{x}D^{1}_{\underline{G}_{A}}(u)\,du, DG¯A2(x)=xDG¯A1(u)𝑑uD^{2}_{\overline{G}_{A}}(x)=\int_{-\infty}^{x}D^{1}_{\overline{G}_{A}}(u)\,du, and

xuG¯A(u)𝑑u𝑑FA(u|ZA=zA,ZB=zB)\displaystyle\int_{-\infty}^{x}\int_{-\infty}^{u}\underline{G}_{A}(u^{\prime})\,du^{\prime}dF_{A}\left(u|Z^{A}=z_{A},Z^{B}=z_{B}\right) =xDG¯A1(u)𝑑FA(u|ZA=zA,ZB=zB)\displaystyle=\int_{-\infty}^{x}D^{1}_{\underline{G}_{A}}(u)dF_{A}\left(u|Z^{A}=z_{A},Z^{B}=z_{B}\right)
=𝔼FA(|ZA=zA,ZB=zB)[DG¯A2(YA)R0(YA,x)],\displaystyle=\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=z_{A},Z^{B}=z_{B}\right)}\left[D^{2}_{\underline{G}_{A}}(Y^{A})\,R_{0}(Y^{A},x)\right],

we are done with s=2s=2, as x𝒳Ax\in\mathcal{X}_{A} was arbitrary.

Now we focus on s=3s=3. Let x𝒳Ax\in\mathcal{X}_{A}. Since D¯NA2(x)DNA2(x)D¯NA2(x)\underline{D}_{N_{A}}^{2}(x)\leq D_{N_{A}}^{2}(x)\leq\overline{D}_{N_{A}}^{2}(x) and DNA3(x)=xDNA2(u)𝑑uD_{N_{A}}^{3}(x)=\int_{-\infty}^{x}D_{N_{A}}^{2}(u)\,du, we can integrate all sides of these inequalities to obtain

D¯NA3(x)=xD¯NA2(u)𝑑uDNA3(x)xD¯NA2(u)𝑑u=D¯NA3(x).\displaystyle\underline{D}_{N_{A}}^{3}(x)=\int_{-\infty}^{x}\underline{D}_{N_{A}}^{2}(u)\,du\leq D_{N_{A}}^{3}(x)\leq\int_{-\infty}^{x}\overline{D}_{N_{A}}^{2}(u)\,du=\overline{D}_{N_{A}}^{3}(x).

Noting that

D¯NA3(x)\displaystyle\underline{D}_{N_{A}}^{3}(x) =x(δ111δ00FA(u|ZA=ZB=1)+δ101δ00FA(u|ZA=1,ZB=0))DG¯A2(u)𝑑u\displaystyle=\int_{-\infty}^{x}\left(\frac{\delta_{11}}{1-\delta_{00}}\,F_{A}\left(u|Z^{A}=Z^{B}=1\right)+\frac{\delta_{10}}{1-\delta_{00}}\,F_{A}\left(u|Z^{A}=1,Z^{B}=0\right)\right)D^{2}_{\underline{G}_{A}}(u)\,du
δ111δ00x𝔼FA(|ZA=ZB=1)[DG¯A2(YA)R0(YA,u)]𝑑u\displaystyle\quad-\frac{\delta_{11}}{1-\delta_{00}}\,\int_{-\infty}^{x}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{2}_{\underline{G}_{A}}(Y^{A})\,R_{0}(Y^{A},u)\right]\,du
δ101δ00x𝔼FA(|ZA=1,ZB=0)[DG¯A2(YA)R0(YA,u)]𝑑u,and\displaystyle\quad-\frac{\delta_{10}}{1-\delta_{00}}\,\int_{-\infty}^{x}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{2}_{\underline{G}_{A}}(Y^{A})\,R_{0}(Y^{A},u)\right]\,du,\quad\text{and}
D¯NA3(x)\displaystyle\overline{D}_{N_{A}}^{3}(x) =x(δ111δ00FA(u|ZA=ZB=1)+δ101δ00FA(u|ZA=1,ZB=0))DG¯A2(u)𝑑u\displaystyle=\int_{-\infty}^{x}\left(\frac{\delta_{11}}{1-\delta_{00}}\,F_{A}\left(u|Z^{A}=Z^{B}=1\right)+\frac{\delta_{10}}{1-\delta_{00}}\,F_{A}\left(u|Z^{A}=1,Z^{B}=0\right)\right)D^{2}_{\overline{G}_{A}}(u)\,du
δ111δ00x𝔼FA(|ZA=ZB=1)[DG¯A2(YA)R0(YA,u)]𝑑u\displaystyle\quad-\frac{\delta_{11}}{1-\delta_{00}}\,\int_{-\infty}^{x}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{2}_{\overline{G}_{A}}(Y^{A})\,R_{0}(Y^{A},u)\right]\,du
δ101δ00x𝔼FA(|ZA=1,ZB=0)[DG¯A2(YA)R0(YA,u)]𝑑u,\displaystyle\quad-\frac{\delta_{10}}{1-\delta_{00}}\,\int_{-\infty}^{x}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{2}_{\overline{G}_{A}}(Y^{A})\,R_{0}(Y^{A},u)\right]\,du,

we can apply the same integration by parts technique, as in the case s=2s=2, to the first terms of these expressions to simplify them, and for the remaining terms we interchange integration and expectation to simply them. Implementing these operations results in

D¯NA3(x)\displaystyle\underline{D}_{N_{A}}^{3}(x) =(δ111δ00FA(x|ZA=ZB=1)+δ101δ00FA(x|ZA=1,ZB=0))DG¯A3(x)\displaystyle=\left(\frac{\delta_{11}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=Z^{B}=1\right)+\frac{\delta_{10}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\right)D^{3}_{\underline{G}_{A}}(x)
δ111δ00(𝔼FA(|ZA=ZB=1)[DG¯A3(YA)R0(YA,x)]+𝔼FA(|ZA=ZB=1)[DG¯A2(YA)R1(YA,x)])\displaystyle-\frac{\delta_{11}}{1-\delta_{00}}\left(\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{3}_{\underline{G}_{A}}(Y^{A})\,R_{0}(Y^{A},x)\right]+\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{2}_{\underline{G}_{A}}(Y^{A})\,R_{1}(Y^{A},x)\right]\right)
δ101δ00(𝔼FA(|ZA=1,ZB=0)[DG¯A3(YA)R0(YA,x)]+𝔼FA(|ZA=1,ZB=0)[DG¯A2(YA)R1(YA,x)]),and\displaystyle-\frac{\delta_{10}}{1-\delta_{00}}\left(\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{3}_{\underline{G}_{A}}(Y^{A})\,R_{0}(Y^{A},x)\right]+\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{2}_{\underline{G}_{A}}(Y^{A})\,R_{1}(Y^{A},x)\right]\right),\quad\text{and}
D¯NA3(x)\displaystyle\overline{D}_{N_{A}}^{3}(x) =(δ111δ00FA(u|ZA=ZB=1)+δ101δ00FA(u|ZA=1,ZB=0))DG¯A3(x)\displaystyle=\left(\frac{\delta_{11}}{1-\delta_{00}}\,F_{A}\left(u|Z^{A}=Z^{B}=1\right)+\frac{\delta_{10}}{1-\delta_{00}}\,F_{A}\left(u|Z^{A}=1,Z^{B}=0\right)\right)D^{3}_{\overline{G}_{A}}(x)
δ111δ00(𝔼FA(|ZA=ZB=1)[DG¯A3(YA)R0(YA,x)]𝔼FA(|ZA=ZB=1)[DG¯A2(YA)R1(YA,x)])\displaystyle-\frac{\delta_{11}}{1-\delta_{00}}\left(\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{3}_{\overline{G}_{A}}(Y^{A})\,R_{0}(Y^{A},x)\right]\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{2}_{\overline{G}_{A}}(Y^{A})\,R_{1}(Y^{A},x)\right]\right)
δ101δ00(𝔼FA(|ZA=1,ZB=0)[DG¯A2(YA)R0(YA,x)]+𝔼FA(|ZA=1,ZB=0)[DG¯A2(YA)R1(YA,x)])\displaystyle-\frac{\delta_{10}}{1-\delta_{00}}\left(\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{2}_{\overline{G}_{A}}(Y^{A})\,R_{0}(Y^{A},x)\right]+\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{2}_{\overline{G}_{A}}(Y^{A})\,R_{1}(Y^{A},x)\right]\right)

where we have used DG¯A3(x)=xDG¯A2(u)𝑑uD^{3}_{\underline{G}_{A}}(x)=\int_{-\infty}^{x}D^{2}_{\underline{G}_{A}}(u)\,du, DG¯A3(x)=xDG¯A2(u)𝑑uD^{3}_{\overline{G}_{A}}(x)=\int_{-\infty}^{x}D^{2}_{\overline{G}_{A}}(u)\,du,

x𝔼FA(|ZA=zA,ZB=zB)[DG¯A2(YA)R0(YA,u)]𝑑u\displaystyle\int_{-\infty}^{x}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=z_{A},Z^{B}=z_{B}\right)}\left[D^{2}_{\underline{G}_{A}}(Y^{A})\,R_{0}(Y^{A},u)\right]\,du =xuDG¯A2(u)𝑑FA(u|ZA=zA,ZB=zB)𝑑u\displaystyle=\int_{-\infty}^{x}\int_{-\infty}^{u}D^{2}_{\underline{G}_{A}}(u^{\prime})\,dF_{A}\left(u^{\prime}|Z^{A}=z_{A},Z^{B}=z_{B}\right)du
=𝔼FA(|ZA=zA,ZB=zB)[DG¯A2(YA)R1(YA,x)],\displaystyle=\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=z_{A},Z^{B}=z_{B}\right)}\left[D^{2}_{\underline{G}_{A}}(Y^{A})\,R_{1}(Y^{A},x)\right],

and an identical expression as the preceding one but with G¯A\underline{G}_{A} replaced with G¯A\overline{G}_{A}.

Proceeding by induction on s+s\in\mathbb{Z}_{+}, once we have expressions for D¯NAs1\underline{D}_{N_{A}}^{s-1} and D¯NAs1\overline{D}_{N_{A}}^{s-1}, we can repeat similar steps to those for the case of s=3s=3, but with appropriate adjustments, to obtain the expressions for D¯NAs(x)\underline{D}_{N_{A}}^{s}(x) and D¯NAs(x)\overline{D}_{N_{A}}^{s}(x) for each x𝒳Ax\in\mathcal{X}_{A}. We omit the details for brevity.

Turning to population BB, we only provide a brief description for deriving D¯NBs\underline{D}_{N_{B}}^{s} and D¯NBs\overline{D}_{N_{B}}^{s}, as it follows steps identical to those for population AA, but with a minor adjustment. The adjustment is that unlike the derivations for population AA, we now must account for the two set of inequalities (D.2) and (D.3), representing the restrictions on the parameter space, which now include restrictions on wave nonresponse. For s=1s=1 and x𝒳Bx\in\mathcal{X}_{B}, we apply the Law of Total Probability to FB(x)F_{B}(x) and use Bayes’ Theorem to obtain

FB(x)=FB(x|ZA=ZB=1)1Prob(ZA=ZB=0|YBx)Prob(ZA=1,ZB=0|YBx)δ11.\displaystyle F_{B}(x)=\frac{F_{B}\left(x|Z^{A}=Z^{B}=1\right)}{1-\text{Prob}\left(Z^{A}=Z^{B}=0|Y^{B}\leq x\right)-\text{Prob}\left(Z^{A}=1,Z^{B}=0|Y^{B}\leq x\right)}\,\delta_{11}.

Now we can use the inequalities (D.2) and (D.3) for K=BK=B to substitute out the propensities and derive the bounds D¯NB1(x)\underline{D}_{N_{B}}^{1}(x) and D¯NB1(x)\overline{D}_{N_{B}}^{1}(x), so that D¯NB1(x)DNB1(x)D¯NB1(x)\underline{D}_{N_{B}}^{1}(x)\leq D_{N_{B}}^{1}(x)\leq\overline{D}_{N_{B}}^{1}(x). Since x𝒳Bx\in\mathcal{X}_{B} was arbitrary, these inequalities hold for each x𝒳Bx\in\mathcal{X}_{B}. Now we can integrate all sides of this inequality, to obtain the bounds D¯NB2(x)\underline{D}_{N_{B}}^{2}(x) and D¯NB2(x)\overline{D}_{N_{B}}^{2}(x) for each x𝒳Bx\in\mathcal{X}_{B}, which like with population AA, the derivations invovle the use of Integration by Parts and interchanging expectation and integration. Proceeding by induction on s+s\in\mathbb{Z}_{+}, once we have expressions for D¯NBs1\underline{D}_{N_{B}}^{s-1} and D¯NBs1\overline{D}_{N_{B}}^{s-1}, we can repeat similar derivations, but with appropriate adjustments, to obtain the expressions for D¯NBs(x)\underline{D}_{N_{B}}^{s}(x) and D¯NBs(x)\overline{D}_{N_{B}}^{s}(x) for each x𝒳Ax\in\mathcal{X}_{A}. We omit the details for brevity. ∎

D.4 Example 4: KS Neighborhood of MCAR

Recall that Example 4 is based on Kline and Santos (2013), who put forward a construction using the maximal Kolmogorov-Smirnov distance between the distributions of missing and observed outcomes. Their approach builds a neighborhood for the CDFs

FA(|ZA=ZB=0),FB(|ZA=ZB=0),andFB(|ZA=1,ZB=0),F_{A}\left(\cdot|Z^{A}=Z^{B}=0\right),F_{B}\left(\cdot|Z^{A}=Z^{B}=0\right),\quad\text{and}\quad F_{B}\left(\cdot|Z^{A}=1,Z^{B}=0\right),

according to the maximal Kolmogorov-Smirnov distance using the conditions in (D.7). Let γA,γB00,γB10[0,1]\gamma_{A},\gamma^{00}_{B},\gamma^{10}_{B}\in[0,1] be such that

supx𝒳A\displaystyle\sup_{x\in\mathcal{X}_{A}} |FA(x|ZA=ZB=0)FA(x|ZA=ZB=1)|γA,\displaystyle\left|F_{A}\left(x|Z^{A}=Z^{B}=0\right)-F_{A}\left(x|Z^{A}=Z^{B}=1\right)\right|\leq\gamma_{A}, (D.4)
supx𝒳B\displaystyle\sup_{x\in\mathcal{X}_{B}} |FB(x|ZA=ZB=0)FB(x|ZA=ZB=1)|γB00,and\displaystyle\left|F_{B}\left(x|Z^{A}=Z^{B}=0\right)-F_{B}\left(x|Z^{A}=Z^{B}=1\right)\right|\leq\gamma^{00}_{B},\quad\text{and} (D.5)
supx𝒳B\displaystyle\sup_{x\in\mathcal{X}_{B}} |FB(x|ZA=1,ZB=0)FB(x|ZA=1,ZB=1)|γB10,\displaystyle\left|F_{B}\left(x|Z^{A}=1,Z^{B}=0\right)-F_{B}\left(x|Z^{A}=1,Z^{B}=1\right)\right|\leq\gamma^{10}_{B}, (D.6)

which are predesignated by the practitioner, where MCAR means

FK(x|ZA=ZB=1)\displaystyle F_{K}\left(x|Z^{A}=Z^{B}=1\right) =FK(x|ZA=ZB=0)x𝒳K,K=A,B,and\displaystyle=F_{K}\left(x|Z^{A}=Z^{B}=0\right)\quad\forall x\in\mathcal{X}_{K},K=A,B,\quad\text{and} (D.7)
FB(x|ZA=ZB=1)\displaystyle F_{B}\left(x|Z^{A}=Z^{B}=1\right) =FB(x|ZA=1,ZB=0)x𝒳B.\displaystyle=F_{B}\left(x|Z^{A}=1,Z^{B}=0\right)\quad\forall x\in\mathcal{X}_{B}.
Proposition D.4.

Let γA,γB00,γB10[0,1]\gamma_{A},\gamma^{00}_{B},\gamma^{10}_{B}\in[0,1], and suppose that (D.4) - (D.6) hold. For each x[t¯,t¯]x\in[\underline{t},\overline{t}] and ss\in\mathbb{N}, the corresponding bounds on the dominance functions are

D¯NAs(x)\displaystyle\underline{D}_{N_{A}}^{s}(x) =𝔼FA(x|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]](δ11+(1γA)δ00),\displaystyle=\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,(\delta_{11}+(1-\gamma_{A})\delta_{00}),
+𝔼FA(x|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}
D¯NAs(x)\displaystyle\overline{D}_{N_{A}}^{s}(x) =D¯NAs(x)+(xY¯A)s1(s1)!γAδ00,\displaystyle=\underline{D}_{N_{A}}^{s}(x)+\frac{(x-\underline{Y}^{A})^{s-1}}{(s-1)!}\,\gamma_{A}\delta_{00},
D¯NBs(x)\displaystyle\underline{D}_{N_{B}}^{s}(x) =𝔼FB(x|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]](δ11+(1γB00)δ00+(1γB10)δ10),and\displaystyle=\mathbbm{E}_{F_{B}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,(\delta_{11}+(1-\gamma^{00}_{B})\delta_{00}+(1-\gamma^{10}_{B})\delta_{10}),\quad\text{and}
D¯NBs(x)\displaystyle\overline{D}_{N_{B}}^{s}(x) =D¯NBs(x)+(xY¯B)s1(s1)!(γB00δ00+γB10δ10),\displaystyle=\underline{D}_{N_{B}}^{s}(x)+\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}\,(\gamma^{00}_{B}\delta_{00}+\gamma^{10}_{B}\delta_{10}),

where Y¯K=inf𝒳K\underline{Y}^{K}=\inf\mathcal{X}_{K}, for K=A,BK=A,B.

Proof.

The proof proceeds by the direct method. Throughout, we adopt the convention 0×±=00\times\pm\infty=0. For s=1s=1, the restrictions (D.4) - (D.6) yields bounds via the decomposition having the form

FA(x|ZA=ZB=0)\displaystyle F_{A}\left(x|Z^{A}=Z^{B}=0\right) =(1γA)FA(x|ZA=ZB=1)+γAGA(x)\displaystyle=(1-\gamma_{A})F_{A}\left(x|Z^{A}=Z^{B}=1\right)+\gamma_{A}G_{A}(x)
FB(x|ZA=ZB=0)\displaystyle F_{B}\left(x|Z^{A}=Z^{B}=0\right) =(1γB00)FB(x|ZA=ZB=1)+γB00GB00(x)\displaystyle=(1-\gamma^{00}_{B})F_{B}\left(x|Z^{A}=Z^{B}=1\right)+\gamma^{00}_{B}G^{00}_{B}(x)
FB(x|ZA=1,ZB=0)\displaystyle F_{B}\left(x|Z^{A}=1,Z^{B}=0\right) =(1γB10)FB(x|ZA=ZB=1)+γB10GB10(x),\displaystyle=(1-\gamma^{10}_{B})F_{B}\left(x|Z^{A}=Z^{B}=1\right)+\gamma^{10}_{B}G^{10}_{B}(x),

for each xx, where GA,GB00,GB10G_{A},G^{00}_{B},G^{10}_{B} are unknown CDFs. Focusing on population AA, let x[t¯,t¯]x\in[\underline{t},\overline{t}], the Law of Total Probability applied to FA(x)F_{A}(x) yields

FA(x)\displaystyle F_{A}(x) =FA(x|ZA=ZB=1)δ11+FA(x|ZA=1,ZB=0)δ10+FA(x|ZA=ZB=0)δ00\displaystyle=F_{A}\left(x|Z^{A}=Z^{B}=1\right)\,\delta_{11}+F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\,\delta_{10}+F_{A}\left(x|Z^{A}=Z^{B}=0\right)\,\delta_{00}
=FA(x|ZA=ZB=1)δ11+FA(x|ZA=1,ZB=0)δ10\displaystyle=F_{A}\left(x|Z^{A}=Z^{B}=1\right)\,\delta_{11}+F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\,\delta_{10}
+δ00(1γA)FA(x|ZA=ZB=1)+δ00γAGA(x)\displaystyle\qquad+\delta_{00}\,(1-\gamma_{A})F_{A}\left(x|Z^{A}=Z^{B}=1\right)+\delta_{00}\,\gamma_{A}G_{A}(x)
=(δ00(1γA)+δ11)FA(x|ZA=ZB=1)+FA(x|ZA=1,ZB=0)δ10+δ00γAGA(x).\displaystyle=\left(\delta_{00}\,(1-\gamma_{A})+\delta_{11}\right)F_{A}\left(x|Z^{A}=Z^{B}=1\right)+F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\,\delta_{10}+\delta_{00}\,\gamma_{A}G_{A}(x).

Now since GAG_{A} is a CDF, GA(x)[0,1]G_{A}(x)\in[0,1], holds, implying the worst-case CDF bounds F¯A(x)FA(x)F¯A(x)\underline{F}_{A}(x)\leq F_{A}(x)\leq\overline{F}_{A}(x), where

F¯A(x)\displaystyle\overline{F}_{A}(x) ={δ00γAx=Y¯A(δ00(1γA)+δ11)FA(x|ZA=ZB=1)+FA(x|ZA=1,ZB=0)δ10+δ00γAx>Y¯A0otherwise\displaystyle=\begin{cases}\delta_{00}\,\gamma_{A}&x=\underline{Y}^{A}\\ \left(\delta_{00}\,(1-\gamma_{A})+\delta_{11}\right)F_{A}\left(x|Z^{A}=Z^{B}=1\right)+F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\,\delta_{10}+\delta_{00}\,\gamma_{A}&x>\underline{Y}^{A}\\ 0&\text{otherwise}\end{cases}
F¯A(x)\displaystyle\underline{F}_{A}(x) ={(δ00(1γA)+δ11)FA(x|ZA=ZB=1)+FA(x|ZA=1,ZB=0)δ10Y¯Ax<Y¯A1x=Y¯A0otherwise.\displaystyle=\begin{cases}\left(\delta_{00}\,(1-\gamma_{A})+\delta_{11}\right)F_{A}\left(x|Z^{A}=Z^{B}=1\right)+F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\,\delta_{10}&\underline{Y}^{A}\leq x<\overline{Y}^{A}\\ 1&x=\overline{Y}^{A}\\ 0&\text{otherwise}.\end{cases}

These bounds are sharp. Here, we have D¯NA1(x)=F¯A(x)\overline{D}_{N_{A}}^{1}(x)=\overline{F}_{A}(x) and D¯NA1(x)=F¯A(x)\underline{D}_{N_{A}}^{1}(x)=\underline{F}_{A}(x). As x𝒳Ax\in\mathcal{X}_{A} was arbitrary, we done with the case s=1s=1. For s=2s=2, we integrate all sides of D¯NA1(x)FA(x)D¯NA1(x)\underline{D}_{N_{A}}^{1}(x)\leq F_{A}(x)\leq\overline{D}_{N_{A}}^{1}(x) as such

xD¯NA1(u)𝑑uxFA(u)𝑑uxD¯NA1(u)𝑑u,\displaystyle\int_{-\infty}^{x}\underline{D}_{N_{A}}^{1}(u)\,du\leq\int_{-\infty}^{x}F_{A}(u)\,du\leq\int_{-\infty}^{x}\overline{D}_{N_{A}}^{1}(u)\,du,

and recognizing that D¯NA2(x)=xD¯NA1(u)𝑑u\underline{D}_{N_{A}}^{2}(x)=\int_{-\infty}^{x}\underline{D}_{N_{A}}^{1}(u)\,du, DNA2(x)=xFA(u)𝑑uD_{N_{A}}^{2}(x)=\int_{-\infty}^{x}F_{A}(u)\,du, and D¯NA2(x)=xD¯NA1(u)𝑑u\overline{D}_{N_{A}}^{2}(x)=\int_{-\infty}^{x}\overline{D}_{N_{A}}^{1}(u)\,du, we must obtain the forms of xD¯NA1(u)𝑑u\int_{-\infty}^{x}\underline{D}_{N_{A}}^{1}(u)\,du and xD¯NA1(u)𝑑u\int_{-\infty}^{x}\overline{D}_{N_{A}}^{1}(u)\,du to complete the proof in this case. Towards that end, using integration by parts

xD¯NA1(u)𝑑u\displaystyle\int_{-\infty}^{x}\underline{D}_{N_{A}}^{1}(u)\,du =F¯A(x)x(0×)xudF¯A(u)\displaystyle=\underline{F}_{A}(x)x-(0\times-\infty)-\int_{-\infty}^{x}u\,d\underline{F}_{A}(u)
=F¯A(x)xxu𝑑F¯A(u)\displaystyle=\underline{F}_{A}(x)x-\int_{-\infty}^{x}u\,d\underline{F}_{A}(u)
=(xu)𝟙[ux]𝑑F¯A(u)\displaystyle=\int_{\mathbb{R}}(x-u)\mathbbm{1}\left[u\leq x\right]\,d\underline{F}_{A}(u)
=(δ00(1γA)+δ11)𝔼FA(x|ZA=ZB=1)[(xYA) 1[YAx]]\displaystyle=\left(\delta_{00}\,(1-\gamma_{A})+\delta_{11}\right)\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[(x-Y^{A})\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]
+δ10𝔼FA(x|ZA=1,ZB=0)[(xYA) 1[YAx]],\displaystyle\quad+\delta_{10}\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[(x-Y^{A})\,\mathbbm{1}\left[Y^{A}\leq x\right]\right],

and

xD¯NA1(u)𝑑u\displaystyle\int_{-\infty}^{x}\overline{D}_{N_{A}}^{1}(u)\,du =F¯A(x)x(0×)xudF¯A(u)\displaystyle=\overline{F}_{A}(x)x-(0\times-\infty)-\int_{-\infty}^{x}u\,d\overline{F}_{A}(u)
=F¯A(x)xxu𝑑F¯A(u)\displaystyle=\overline{F}_{A}(x)x-\int_{-\infty}^{x}u\,d\overline{F}_{A}(u)
=(xu)𝟙[ux]𝑑F¯A(u)\displaystyle=\int_{\mathbb{R}}(x-u)\mathbbm{1}\left[u\leq x\right]\,d\overline{F}_{A}(u)
=(δ00(1γA)+δ11)xFA(u|ZA=ZB=1)𝑑u\displaystyle=\left(\delta_{00}\,(1-\gamma_{A})+\delta_{11}\right)\int_{-\infty}^{x}F_{A}\left(u|Z^{A}=Z^{B}=1\right)\,du
=(δ00(1γA)+δ11)𝔼FA(x|ZA=ZB=1)[(xYA) 1[YAx]]\displaystyle=\left(\delta_{00}\,(1-\gamma_{A})+\delta_{11}\right)\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[(x-Y^{A})\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]
+δ10𝔼FA(x|ZA=1,ZB=0)[(xYA) 1[YAx]]+(xY¯A)γAδ00\displaystyle\quad+\delta_{10}\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[(x-Y^{A})\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]+(x-\underline{Y}^{A})\gamma_{A}\delta_{00}

Now for s=3s=3, integrate all sides of D¯NA2(x)DNA2(x)D¯NA2(x)\underline{D}_{N_{A}}^{2}(x)\leq D_{N_{A}}^{2}(x)\leq\overline{D}_{N_{A}}^{2}(x) as such

xD¯NA2(u)𝑑uxDNA2(u)𝑑uxD¯NA2(u)𝑑u,\displaystyle\int_{-\infty}^{x}\underline{D}_{N_{A}}^{2}(u)\,du\leq\int_{-\infty}^{x}D_{N_{A}}^{2}(u)\,du\leq\int_{-\infty}^{x}\overline{D}_{N_{A}}^{2}(u)\,du,

and recognizing that D¯NA3(x)=xD¯NA2(u)𝑑u\underline{D}_{N_{A}}^{3}(x)=\int_{-\infty}^{x}\underline{D}_{N_{A}}^{2}(u)\,du, DNA3(x)=xDNA2(u)𝑑uD_{N_{A}}^{3}(x)=\int_{-\infty}^{x}D_{N_{A}}^{2}(u)\,du, and D¯NA3(x)=xD¯NA2(u)𝑑u\overline{D}_{N_{A}}^{3}(x)=\int_{-\infty}^{x}\overline{D}_{N_{A}}^{2}(u)\,du, we must obtain the forms of xD¯NA2(u)𝑑u\int_{-\infty}^{x}\underline{D}_{N_{A}}^{2}(u)\,du and xD¯NA2(u)𝑑u\int_{-\infty}^{x}\overline{D}_{N_{A}}^{2}(u)\,du to complete the proof in this case. We have

xD¯NA2(u)𝑑u\displaystyle\int_{-\infty}^{x}\underline{D}_{N_{A}}^{2}(u)\,du =x(uu)𝟙[uu]𝑑F¯A(u)𝑑u\displaystyle=\int_{-\infty}^{x}\int_{\mathbb{R}}(u^{\prime}-u)\mathbbm{1}\left[u\leq u^{\prime}\right]\,d\underline{F}_{A}(u)\,du^{\prime}
=x(uu)𝟙[uu]𝑑u𝑑F¯A(u)\displaystyle=\int_{\mathbb{R}}\int_{-\infty}^{x}(u^{\prime}-u)\mathbbm{1}\left[u\leq u^{\prime}\right]\,du^{\prime}\,d\underline{F}_{A}(u)
=(xu)22!𝑑F¯A(u)\displaystyle=\int_{\mathbb{R}}\frac{(x-u)^{2}}{2!}\,d\underline{F}_{A}(u)
=𝔼FA(x|ZA=ZB=1)[(xYA)22 1[YAx]](δ11+(1γA)δ00),\displaystyle=\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{2}}{2}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,(\delta_{11}+(1-\gamma_{A})\delta_{00}),
+𝔼FA(x|ZA=1,ZB=0)[(xYA)22 1[YAx]]δ10\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{2}}{2}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}

and

xD¯NA2(u)𝑑u\displaystyle\int_{-\infty}^{x}\overline{D}_{N_{A}}^{2}(u)\,du =x(uu)𝟙[uu]𝑑F¯A(u)𝑑u\displaystyle=\int_{-\infty}^{x}\int_{\mathbb{R}}(u^{\prime}-u)\mathbbm{1}\left[u\leq u^{\prime}\right]\,d\overline{F}_{A}(u)\,du^{\prime}
=x(uu)𝟙[uu]𝑑u𝑑F¯A(u)\displaystyle=\int_{\mathbb{R}}\int_{-\infty}^{x}(u^{\prime}-u)\mathbbm{1}\left[u\leq u^{\prime}\right]\,du^{\prime}\,d\overline{F}_{A}(u)
=(xu)22!𝑑F¯A(u)\displaystyle=\int_{\mathbb{R}}\frac{(x-u)^{2}}{2!}\,d\overline{F}_{A}(u)
=xD¯NA2(u)𝑑u+(xY¯A)22γAδ00.\displaystyle=\int_{-\infty}^{x}\underline{D}_{N_{A}}^{2}(u)\,du+\frac{(x-\underline{Y}^{A})^{2}}{2}\,\gamma_{A}\delta_{00}.

Proceeding by induction on s+s\in\mathbb{Z}_{+}, once we have expressions for D¯NAs1\underline{D}_{N_{A}}^{s-1} and D¯NAs1\overline{D}_{N_{A}}^{s-1}, we can repeat similar steps to those for the case of s=3s=3, but with appropriate adjustments, to obtain the expressions for D¯NAs(x)\underline{D}_{N_{A}}^{s}(x) and D¯NAs(x)\overline{D}_{N_{A}}^{s}(x) for each x𝒳Ax\in\mathcal{X}_{A}. We omit the details for brevity.

Turning to population BB, let x[t¯,t¯]x\in[\underline{t},\overline{t}], the Law of Total Probability applied to FB(x)F_{B}(x) yields

FB(x)\displaystyle F_{B}(x) =FB(x|ZA=ZB=1)δ11+FB(x|ZA=1,ZB=0)δ10+FB(x|ZA=ZB=0)δ00\displaystyle=F_{B}\left(x|Z^{A}=Z^{B}=1\right)\,\delta_{11}+F_{B}\left(x|Z^{A}=1,Z^{B}=0\right)\,\delta_{10}+F_{B}\left(x|Z^{A}=Z^{B}=0\right)\,\delta_{00}
=FB(x|ZA=ZB=1)δ11+((1γB10)FB(x|ZA=ZB=1)+γB10GB10(x))δ10\displaystyle=F_{B}\left(x|Z^{A}=Z^{B}=1\right)\,\delta_{11}+\left((1-\gamma^{10}_{B})F_{B}\left(x|Z^{A}=Z^{B}=1\right)+\gamma^{10}_{B}G^{10}_{B}(x)\right)\,\delta_{10}
+δ00(1γB00)FB(x|ZA=ZB=1)+δ00γB00GB00(x)\displaystyle\qquad+\delta_{00}\,(1-\gamma^{00}_{B})F_{B}\left(x|Z^{A}=Z^{B}=1\right)+\delta_{00}\,\gamma^{00}_{B}G^{00}_{B}(x)
=(δ00(1γB00)+δ10(1γB10)+δ11)FB(x|ZA=ZB=1)+δ00γB00GB00(x)\displaystyle=\left(\delta_{00}\,(1-\gamma^{00}_{B})+\delta_{10}\,(1-\gamma^{10}_{B})+\delta_{11}\right)F_{B}\left(x|Z^{A}=Z^{B}=1\right)+\delta_{00}\,\gamma^{00}_{B}G^{00}_{B}(x)
+δ10γB10GB10(x).\displaystyle\qquad+\delta_{10}\,\gamma^{10}_{B}G^{10}_{B}(x).

Now since GB00G^{00}_{B} and GB10G^{10}_{B} are CDFs, GB00(x),GB00(x)[0,1]G^{00}_{B}(x),G^{00}_{B}(x)\in[0,1], holds, implying the worst-case CDF bounds F¯B(x)FB(x)F¯B(x)\underline{F}_{B}(x)\leq F_{B}(x)\leq\overline{F}_{B}(x), where

F¯B(x)\displaystyle\overline{F}_{B}(x) ={δ10γB10+δ00γB00x=Y¯B(δ00(1γB00)+δ10(1γB10)+δ11)FB(x|ZA=ZB=1)+δ10γB10+δ00γB00x>Y¯B0otherwise\displaystyle=\begin{cases}\delta_{10}\,\gamma^{10}_{B}+\delta_{00}\,\gamma^{00}_{B}&x=\underline{Y}^{B}\\ \left(\delta_{00}\,(1-\gamma^{00}_{B})+\delta_{10}\,(1-\gamma^{10}_{B})+\delta_{11}\right)F_{B}\left(x|Z^{A}=Z^{B}=1\right)+\delta_{10}\,\gamma^{10}_{B}+\delta_{00}\,\gamma^{00}_{B}&x>\underline{Y}^{B}\\ 0&\text{otherwise}\end{cases}
F¯B(x)\displaystyle\underline{F}_{B}(x) ={(δ00(1γB00)+δ10(1γB10)+δ11)FB(x|ZA=ZB=1)Y¯Bx<Y¯B1x=Y¯B0otherwise.\displaystyle=\begin{cases}\left(\delta_{00}\,(1-\gamma^{00}_{B})+\delta_{10}\,(1-\gamma^{10}_{B})+\delta_{11}\right)F_{B}\left(x|Z^{A}=Z^{B}=1\right)&\underline{Y}^{B}\leq x<\overline{Y}^{B}\\ 1&x=\overline{Y}^{B}\\ 0&\text{otherwise}.\end{cases}

To derive the bounds, we follows steps identical to those for K=AK=A above, except that we now replace F¯A\underline{F}_{A} and F¯A\overline{F}_{A} with F¯B\underline{F}_{B} and F¯B\overline{F}_{B}, respectively, and calculate the integrals accordingly. We omit the details for brevity. ∎

Appendix E Technical Details for Section 5

E.1 Examples of Bounds for The Testing Problem (5.1)

Example 5.

WC Bounds. The WC bounds can be recovered using the following specification: for each x[t¯,t¯]x\in[\underline{t},\overline{t}],

φ1,NA,NB(x)\displaystyle\varphi_{1,N_{A},N_{B}}(x) =φ4,NA,NB(x)=φ2,NA,NB(x)=(δ11+δ10)and\displaystyle=\varphi_{4,N_{A},N_{B}}(x)=\varphi_{2,N_{A},N_{B}}(x)=-(\delta_{11}+\delta_{10})\quad\text{and}
φ3,NA,NB(x)\displaystyle\varphi_{3,N_{A},N_{B}}(x) =(xY¯B)s1(s1)!δ00+δ10,\displaystyle=\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}\,\delta_{00}+\delta_{10},

where Y¯B=inf𝒳B\underline{Y}^{B}=\inf\mathcal{X}_{B}. Hence, by definition, Y¯Bx\underline{Y}^{B}\leq x for each x[t¯,t¯]x\in[\underline{t},\overline{t}]. It defines θNA,NB(;φNA,NB)=D¯NBs()D¯NAs()\theta_{N_{A},N_{B}}(\cdot;\varphi_{N_{A},N_{B}})=\overline{D}_{N_{B}}^{s}(\cdot)-\underline{D}_{N_{A}}^{s}(\cdot), where for each x[t¯,t¯]x\in[\underline{t},\overline{t}],

D¯NBs(x)\displaystyle\overline{D}_{N_{B}}^{s}(x) =𝔼FB(x|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]]δ11+(xY¯B)s1(s1)!(δ00+δ10)and\displaystyle=\mathbbm{E}_{F_{B}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,\delta_{11}+\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}\,(\delta_{00}+\delta_{10})\quad\text{and}
D¯NAs(x)\displaystyle\underline{D}_{N_{A}}^{s}(x) =𝔼FA(x|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]]δ11\displaystyle=\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{11}
+𝔼FA(x|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10.\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}.
Example 6.

MCAR for Unit Nonresponse. In conjunction with the WC upper bound for FB(|ZA=1,ZB=0)F_{B}(\cdot|Z^{A}=1,Z^{B}=0), the following specification encodes this MCAR assumption: for each x[t¯,t¯]x\in[\underline{t},\overline{t}],

φ1,NA,NB(x)\displaystyle\varphi_{1,N_{A},N_{B}}(x) =φ4,NA,NB(x)=(δ11+δ00)(δ11+δ10)δ11,φ2,NA,NB(x)=(δ11+δ10)and\displaystyle=\varphi_{4,N_{A},N_{B}}(x)=-\frac{(\delta_{11}+\delta_{00})(\delta_{11}+\delta_{10})}{\delta_{11}},\,\varphi_{2,N_{A},N_{B}}(x)=-(\delta_{11}+\delta_{10})\quad\text{and}
φ3,NA,NB(x)\displaystyle\varphi_{3,N_{A},N_{B}}(x) =(xY¯B)s1(s1)!δ10.\displaystyle=\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}\,\delta_{10}.

It defines θNA,NB(;φNA,NB)=D¯NBs()D¯NAs()\theta_{N_{A},N_{B}}(\cdot;\varphi_{N_{A},N_{B}})=\overline{D}_{N_{B}}^{s}(\cdot)-\underline{D}_{N_{A}}^{s}(\cdot), where for each x[t¯,t¯]x\in[\underline{t},\overline{t}],

D¯NBs(x)\displaystyle\overline{D}_{N_{B}}^{s}(x) =𝔼FB(x|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]](δ11+δ00)+(xY¯B)s1(s1)!δ10and\displaystyle=\mathbbm{E}_{F_{B}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,(\delta_{11}+\delta_{00})+\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}\,\delta_{10}\quad\text{and}
D¯NAs(x)\displaystyle\underline{D}_{N_{A}}^{s}(x) =𝔼FA(x|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]](δ11+δ00)\displaystyle=\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,(\delta_{11}+\delta_{00})
+𝔼FA(x|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10.\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}.
Example 7.

Neighborhood Assumption for Unit and Wave Nonresponse. The following specification of φNA,NB\varphi_{N_{A},N_{B}} delivers the desired bounds: for each x[t¯,t¯]x\in[\underline{t},\overline{t}]

φ1(x)\displaystyle\varphi_{1}(x) =φ2(x)=DG¯As(x),φ4(x)=1δ00δ11DG¯Bs(x)and\displaystyle=\varphi_{2}(x)=-D^{s}_{\underline{G}_{A}}(x),\,\varphi_{4}(x)=-\frac{1-\delta_{00}}{\delta_{11}}\,D^{s}_{\overline{G}_{B}}(x)\quad\text{and}
φ3(x)\displaystyle\varphi_{3}(x) =𝟙[s>1]j=0s2𝔼FB(|ZA=ZB=1)[DG¯Bs(YB)Rj(YB,x)]\displaystyle=-\mathbbm{1}[s>1]\sum_{j=0}^{s-2}\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\overline{G}_{B}}(Y^{B})\,R_{j}(Y^{B},x)\right]
+𝟙[s>1]δ111δ00j=0s2𝔼FA(|ZA=ZB=1)[DG¯As(YA)Rj(YA,x)]\displaystyle\qquad+\mathbbm{1}[s>1]\frac{\delta_{11}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\underline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right]
+𝟙[s>1]δ101δ00j=0s2𝔼FA(|ZA=1,ZB=0)[DG¯As(YA)Rj(YA,x)].\displaystyle\qquad+\mathbbm{1}[s>1]\frac{\delta_{10}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{s}_{\underline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right].

This specification defines θNA,NB(;φNA,NB)=D¯NBs()D¯NAs()\theta_{N_{A},N_{B}}(\cdot;\varphi_{N_{A},N_{B}})=\overline{D}_{N_{B}}^{s}(\cdot)-\underline{D}_{N_{A}}^{s}(\cdot), where for each x[t¯,t¯]x\in[\underline{t},\overline{t}],

D¯NAs(x)\displaystyle\underline{D}_{N_{A}}^{s}(x) =(δ111δ00FA(x|ZA=ZB=1)+δ101δ00FA(x|ZA=1,ZB=0))DG¯As(x)\displaystyle=\left(\frac{\delta_{11}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=Z^{B}=1\right)+\frac{\delta_{10}}{1-\delta_{00}}\,F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)\right)D^{s}_{\underline{G}_{A}}(x)
𝟙[s>1]δ111δ00j=0s2𝔼FA(|ZA=ZB=1)[DG¯As(YA)Rj(YA,x)]\displaystyle\qquad-\mathbbm{1}[s>1]\frac{\delta_{11}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\underline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right]
𝟙[s>1]δ101δ00j=0s2𝔼FA(|ZA=1,ZB=0)[DG¯As(YA)Rj(YA,x)]\displaystyle\qquad-\mathbbm{1}[s>1]\frac{\delta_{10}}{1-\delta_{00}}\sum_{j=0}^{s-2}\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[D^{s}_{\underline{G}_{A}}(Y^{A})\,R_{j}(Y^{A},x)\right]
D¯NBs(x)\displaystyle\overline{D}_{N_{B}}^{s}(x) =FB(x|ZA=ZB=1)DG¯Bs(x)𝟙[s>1]j=0s2𝔼FB(|ZA=ZB=1)[DG¯Bs(YB)Rj(YB,x)].\displaystyle=F_{B}\left(x|Z^{A}=Z^{B}=1\right)\,D^{s}_{\overline{G}_{B}}(x)-\mathbbm{1}[s>1]\sum_{j=0}^{s-2}\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[D^{s}_{\overline{G}_{B}}(Y^{B})\,R_{j}(Y^{B},x)\right].
Example 8.

Kline and Santos (2013). In conjunction with the WC bounds on wave nonresponse, the following specification of φNA,NB\varphi_{N_{A},N_{B}} encodes this assumption on unit and wave nonrepsonse: for each x[t¯,t¯]x\in[\underline{t},\overline{t}],

φ1(x)\displaystyle\varphi_{1}(x) =(δ11+(1γA)δ00)(δ11+δ10)δ11,φ2(x)=(δ11+δ10),φ3(x)=(xY¯B)s1(s1)!(γB00δ00+γB10δ10)\displaystyle=-\frac{(\delta_{11}+(1-\gamma_{A})\delta_{00})(\delta_{11}+\delta_{10})}{\delta_{11}},\;\varphi_{2}(x)=-(\delta_{11}+\delta_{10}),\,\varphi_{3}(x)=\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}\,(\gamma^{00}_{B}\delta_{00}+\gamma^{10}_{B}\delta_{10})
andφ4(x)=(δ11+(1γB00)δ00+(1γB10)δ10)(δ11+δ10)δ11.\displaystyle\quad\text{and}\quad\varphi_{4}(x)=-\frac{(\delta_{11}+(1-\gamma^{00}_{B})\delta_{00}+(1-\gamma^{10}_{B})\delta_{10})(\delta_{11}+\delta_{10})}{\delta_{11}}.

It defines θNA,NB(;φNA,NB)=D¯NBs()D¯NAs()\theta_{N_{A},N_{B}}(\cdot;\varphi_{N_{A},N_{B}})=\overline{D}_{N_{B}}^{s}(\cdot)-\underline{D}_{N_{A}}^{s}(\cdot), where for each x[t¯,t¯]x\in[\underline{t},\overline{t}],

D¯NAs(x)\displaystyle\underline{D}_{N_{A}}^{s}(x) =𝔼FA(x|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]](δ11+(1γA)δ00),\displaystyle=\mathbbm{E}_{F_{A}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,(\delta_{11}+(1-\gamma_{A})\delta_{00}),
+𝔼FA(x|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10and\displaystyle\qquad+\mathbbm{E}_{F_{A}\left(x|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\,\delta_{10}\quad\text{and}
D¯NBs(x)\displaystyle\overline{D}_{N_{B}}^{s}(x) =D¯NBs(x)+(xY¯B)s1(s1)!(γB00δ00+γB10δ10)\displaystyle=\underline{D}_{N_{B}}^{s}(x)+\frac{(x-\underline{Y}^{B})^{s-1}}{(s-1)!}\,(\gamma^{00}_{B}\delta_{00}+\gamma^{10}_{B}\delta_{10})

where D¯NBs(x)=𝔼FB(x|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]](δ11+(1γB00)δ00+(1γB10)δ10)\underline{D}_{N_{B}}^{s}(x)=\mathbbm{E}_{F_{B}\left(x|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\,(\delta_{11}+(1-\gamma^{00}_{B})\delta_{00}+(1-\gamma^{10}_{B})\delta_{10}).

E.2 Section 5.5

This section provides the details on the statistical procedure for the testing problem (5.3). It is based on calibration via pseudo-empirical likelihood as in Wu and Rao (2006). When AA represents a wave beyond the first one, the event {ZiA=0,ZiB=1}\{Z_{i}^{A}=0,Z_{i}^{B}=1\} can occur, which was not possible when AA represented the population of the first wave. In words, this event corresponds to the sampled unit ii not responding in wave AA but responding in wave BB. The event {ZiA=0,ZiB=0}\{Z_{i}^{A}=0,Z_{i}^{B}=0\} in the setup of this section now corresponds to unit ii either being a unit nonresponder, or a wave nonresponder that did not respond in waves AA and BB but responded in other waves. This distinction between different types of nonresponse within this event can be meaningful when their characteristics differ (e.g., poor and wealthy individuals). The foregoing general estimating function approach that targets the estimand D¯NAs()D¯NBs()\overline{D}_{N_{A}}^{s}(\cdot)-\underline{D}_{N_{B}}^{s}(\cdot) must be adjusted now to incorporate events of the form {ZiA=0,ZiB=1}\{Z_{i}^{A}=0,Z_{i}^{B}=1\}. For each x[t¯,t¯]x\in[\underline{t},\overline{t}], consider the following estimating function ψs(YA,YB,ZA,ZB,θ(x),φ(x))\psi_{s}\left(Y^{A},Y^{B},Z^{A},Z^{B},\theta(x),\varphi(x)\right), given by

(xYA)s1(s1)![𝟙[YAx,ZA=ZB=1]φ1(x)+𝟙[YAx,ZA=1,ZB=0]φ2(x)]\displaystyle\frac{(x-Y^{A})^{s-1}}{(s-1)!}\left[\mathbbm{1}\left[Y^{A}\leq x,Z^{A}=Z^{B}=1\right]\varphi_{1}(x)+\mathbbm{1}\left[Y^{A}\leq x,Z^{A}=1,Z^{B}=0\right]\varphi_{2}(x)\right] (E.1)
(xYB)s1(s1)![𝟙[YBx,ZA=ZB=1]φ4(x)+𝟙[YBx,ZA=0,ZB=1]φ5(x)]\displaystyle-\frac{(x-Y^{B})^{s-1}}{(s-1)!}\left[\mathbbm{1}\left[Y^{B}\leq x,Z^{A}=Z^{B}=1\right]\varphi_{4}(x)+\mathbbm{1}\left[Y^{B}\leq x,Z^{A}=0,Z^{B}=1\right]\varphi_{5}(x)\right]
+φ3(x)θ(x)\displaystyle\quad+\varphi_{3}(x)-\theta(x)

where φ=[φ1,φ2,φ3,φ4,φ5]\varphi=[\varphi_{1},\varphi_{2},\varphi_{3},\varphi_{4},\varphi_{5}] is a vector of nuisance functionals. The nuisance functions, as in the previous sections of this paper, serves as a vehicle to encode side information of maintained assumptions on nonresponse.

For a given value φ=φNA,NB\varphi=\varphi_{N_{A},N_{B}}, the solution of the census estimating equations

NA1NB1i=1NAj=1NBψs(YiA,YjB,ZiA,ZjB,θ(x),φ(x))=0x[t¯,t¯]\displaystyle N_{A}^{-1}N_{B}^{-1}\sum_{i=1}^{N_{A}}\sum_{j=1}^{N_{B}}\psi_{s}\left(Y_{i}^{A},Y_{j}^{B},Z_{i}^{A},Z_{j}^{B},\theta(x),\varphi(x)\right)=0\quad\forall x\in[\underline{t},\overline{t}]

is

θ(x)\displaystyle\theta(x) =𝔼FA(|ZA=ZB=1)[(xYA)s1(s1)! 1[YAx]]δ11φ1,NA,NB(x)\displaystyle=\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\delta_{11}\,\varphi_{1,N_{A},N_{B}}(x)
+𝔼FA(|ZA=1,ZB=0)[(xYA)s1(s1)! 1[YAx]]δ10φ2,NA,NB(x)\displaystyle+\mathbbm{E}_{F_{A}\left(\cdot|Z^{A}=1,Z^{B}=0\right)}\left[\frac{(x-Y^{A})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{A}\leq x\right]\right]\delta_{10}\,\varphi_{2,N_{A},N_{B}}(x)
𝔼FB(|ZA=ZB=1)[(xYB)s1(s1)! 1[YBx]]δ11φ4,NA,NB(x)\displaystyle-\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\delta_{11}\,\varphi_{4,N_{A},N_{B}}(x)
𝔼FB(|ZA=0,ZB=1)[(xYB)s1(s1)! 1[YBx]]δ01φ5,NA,NB(x)\displaystyle-\mathbbm{E}_{F_{B}\left(\cdot|Z^{A}=0,Z^{B}=1\right)}\left[\frac{(x-Y^{B})^{s-1}}{(s-1)!}\,\mathbbm{1}\left[Y^{B}\leq x\right]\right]\delta_{01}\,\varphi_{5,N_{A},N_{B}}(x)
+φ3(x),\displaystyle+\varphi_{3}(x),

for each x[t¯,t¯]x\in[\underline{t},\overline{t}].

Now we introduce notation regarding the sampled units. Let V{1,2,,NW1}V\subset\{1,2,\ldots,N_{W_{1}}\} denote the survey sample of the target population in the first wave of the panel, and let V={iV:ZiW1=1}V^{\prime}=\left\{i\in V:Z^{W_{1}}_{i}=1\right\}, which consists of units that have responded in the first wave. As those units are followed over time, define

U={iV:either{ZiA=ZiB=1},or{ZiA=1,ZiB=0},or{ZiA=0,ZiB=1}},\displaystyle U=\left\{i\in V^{\prime}:\text{either}\,\left\{Z_{i}^{A}=Z_{i}^{B}=1\right\},\,\text{or}\,\left\{Z_{i}^{A}=1,Z_{i}^{B}=0\right\},\,\text{or}\,\left\{Z_{i}^{A}=0,Z_{i}^{B}=1\right\}\right\}, (E.2)

to be the set of units that are followed form the first wave that have responded in either of the waves corresponding to AA and BB. Also, let Ψi(x;φ^(x))=ψs(YiA,YiB,ZiA,ZiB,0,φ^(x))\Psi_{i}(x;\hat{\varphi}(x))=\psi_{s}\left(Y_{i}^{A},Y_{i}^{B},Z_{i}^{A},Z_{i}^{B},0,\hat{\varphi}(x)\right) for each iUi\in U, where φ^\hat{\varphi} is a plug-in estimator of φNA,NB\varphi_{N_{A},N_{B}} than can depend on VV. Furthermore, define the moment functions

Γ1,i=G0Gi𝟙[ZiA=1]G¯𝟙[ZiA=0]andΓ2,i=Gi𝟙[ZiA=1]+G¯𝟙[ZiA=0]G0\displaystyle\Gamma_{1,i}=G_{0}-G_{i}\mathbbm{1}\left[Z^{A}_{i}=1\right]-\overline{G}\mathbbm{1}\left[Z^{A}_{i}=0\right]\quad\text{and}\quad\Gamma_{2,i}=G_{i}\mathbbm{1}\left[Z^{A}_{i}=1\right]+\underline{G}\mathbbm{1}\left[Z^{A}_{i}=0\right]-G_{0} (E.3)

for each i{1,2,,NA}i\in\{1,2,\ldots,N_{A}\}. Finally, let Γi=[Γ1,i,Γ2,i]\Gamma_{i}=[\Gamma_{1,i},\Gamma_{2,i}]^{\intercal}, and let Γi,b\Gamma_{i,b} denote the subvector of Γi\Gamma_{i} corresponding to the active/binding inequalities in (5.2)

Accordingly, the following pseudo-empirical likelihood statistic defines a restricted testing procedure for the test problem (5.3):

LRaux={2minx[t¯,t¯](LUR,aux(x)LR,aux(x))/Deff^GR(x)ifθ~(x;φ^(x))<0x[t¯,t¯]0,otherwise\displaystyle LR_{\text{aux}}=\begin{cases}2\min\limits_{x\in[\underline{t},\overline{t}]}\left(L_{UR,\text{aux}}(x)-L_{R,\text{aux}}(x)\right)/\widehat{\text{Deff}}_{\text{GR}}(x)&\text{if}\ \tilde{\theta}(x;\hat{\varphi}(x))<0\quad\forall x\in[\underline{t},\overline{t}]\\ 0,&\text{otherwise}\end{cases} (E.4)

where

LR,aux(x)=maxp(0,1]niUWilog(pi)\displaystyle L_{R,\text{aux}}(x)=\max_{\vec{p}\in(0,1]^{n}}\sum_{i\in U}W^{\prime}_{i}\log(p_{i}) s.t.pi>0i,iUWipi=1,iUWipiΨi(x;φ^(x))=0\displaystyle\quad\text{s.t.}\quad p_{i}>0\quad\forall i,\;\sum_{i\in U}W^{\prime}_{i}p_{i}=1,\,\sum_{i\in U}W^{\prime}_{i}p_{i}\Psi_{i}(x;\hat{\varphi}(x))=0 (E.5)
andiUWipiΓ,i0=1,2;\displaystyle\quad\text{and}\,\sum_{i\in U}W^{\prime}_{i}p_{i}\Gamma_{\ell,i}\leq 0\quad\ell=1,2;
LUR,aux(x)=maxp(0,1]niUWilog(pi)\displaystyle L_{UR,\text{aux}}(x)=\max_{\vec{p}\in(0,1]^{n}}\sum_{i\in U}W^{\prime}_{i}\log(p_{i}) s.t.pi>0i,iUWipi=1,\displaystyle\quad\text{s.t.}\quad p_{i}>0\quad\forall i,\;\sum_{i\in U}W^{\prime}_{i}p_{i}=1, (E.6)
andiUWipiΓ,i0=1,2,\displaystyle\quad\text{and}\,\sum_{i\in U}W^{\prime}_{i}p_{i}\Gamma_{\ell,i}\leq 0\quad\ell=1,2,

and θ~(x;φ^)=iUWip~iΨi(x;φ^(x))\tilde{\theta}(x;\hat{\varphi})=\sum_{i\in U}W^{\prime}_{i}\tilde{p}_{i}\Psi_{i}(x;\hat{\varphi}(x)) with {p~i,iU}\{\tilde{p}_{i},i\in U\} the solution of (E.6). The design-effect in this scenario is associated with the estimator θ´(x;φ^(x))=iU(Wi/n)ri(x)\acute{\theta}(x;\hat{\varphi}(x))=\sum_{i\in U}(W^{\prime}_{i}/n)r_{i}(x),

Deff^GR(x)=[n1iU(Wi/n)Ψi2(x;φ^(x))]1Var^(θ´(x;φ^(x))),\displaystyle\widehat{\text{Deff}}_{\text{GR}}(x)=\left[n^{-1}\sum_{i\in U}(W^{\prime}_{i}/n)\Psi^{2}_{i}(x;\hat{\varphi}(x))\right]^{-1}\,\widehat{Var}\left(\acute{\theta}(x;\hat{\varphi}(x))\right), (E.7)

where for each iUi\in U

ri(x)\displaystyle r_{i}(x) =Ψi(x;φ^(x))𝐁(x)Γi,band\displaystyle=\Psi_{i}(x;\hat{\varphi}(x))-{\bf B}^{\intercal}(x)\Gamma_{i,b}\quad\text{and} (E.8)
𝐁(x)\displaystyle{\bf B}(x) =[1NAi=1NAΓi,bΓi,b]1[1NA1NBi=1NAj=1NBΓi,bψs(YiA,YjB,ZiA,ZjB,0,φNA,NB(x))],\displaystyle=\left[\frac{1}{N_{A}}\sum_{i=1}^{N_{A}}\Gamma_{i,b}\,\Gamma_{i,b}^{\intercal}\right]^{-1}\left[\frac{1}{N_{A}}\frac{1}{N_{B}}\sum_{i=1}^{N_{A}}\sum_{j=1}^{N_{B}}\Gamma_{i,b}\,\psi_{s}\left(Y_{i}^{A},Y_{j}^{B},Z_{i}^{A},Z_{j}^{B},0,\varphi_{N_{A},N_{B}}(x)\right)\right], (E.9)

and Var^(θ´(x;φ^(x)))\widehat{Var}\left(\acute{\theta}(x;\hat{\varphi}(x))\right) is an estimator of the design variance Var(θ´(x;φ^(x)))Var\left(\acute{\theta}(x;\hat{\varphi}(x))\right). In estimation of this design-variance, one must estimate 𝐁{\bf B} using its sample version:

𝐁^(x)\displaystyle{\bf\hat{B}}(x) =[iU(Wi/n)Γ^i,bΓ^i,b]1[iU(Wi/n)Γ^i,bΨi(x;φ^(x))],\displaystyle=\left[\sum_{i\in U}(W^{\prime}_{i}/n)\hat{\Gamma}_{i,b}\,\hat{\Gamma}_{i,b}^{\intercal}\right]^{-1}\left[\sum_{i\in U}(W^{\prime}_{i}/n)\hat{\Gamma}_{i,b}\,\Psi_{i}(x;\hat{\varphi}(x))\right],

where Γ^i,b\hat{\Gamma}_{i,b} is exactly Γi,b\Gamma_{i,b} but based on an estimator of the set of active/binding inequalities.

Let ν=[νeq,νb]×dim(Γi,b)\nu=[\nu_{eq},\nu_{b}]\in\mathbb{R}\times\mathbb{R}_{-}^{\text{dim}(\Gamma_{i,b})}. For a fixed nominal level α(0,1)\alpha\in(0,1), the decision rule of the test is to

rejectH03LRaux>c(α),\displaystyle\text{reject}\ H_{0}^{3}\iff LR_{\text{aux}}>c(\alpha), (E.10)

where c(α)c(\alpha) is be the 1α1-\alpha quantile of the distribution for the random variable

infν×dim(Γi,b):νeq=0(νT)Ω1(νT)infν×dim(Γi,b)(νT)Ω1(νT),\displaystyle\inf_{\nu\in\mathbb{R}\times\mathbb{R}_{-}^{\text{dim}(\Gamma_{i,b})}:\nu_{eq}=0}\left(\nu-T\right)^{\intercal}\Omega^{-1}\left(\nu-T\right)-\inf_{\nu\in\mathbb{R}\times\mathbb{R}_{-}^{\text{dim}(\Gamma_{i,b})}}\left(\nu-T\right)^{\intercal}\Omega^{-1}\left(\nu-T\right), (E.11)

where TMVN(𝟎,Ω)T\sim\text{MVN}\left({\bf 0},\Omega\right), and Ω\Omega is the limit of the covariance matrix

1NA1NBi=1NAj=1NB[ψs2(YiA,YjB,ZiA,ZjB,0,φNA,NB(x0))Γi,bψs(YiA,YjB,ZiA,ZjB,0,φNA,NB(x0))Γi,bψs(YiA,YjB,ZiA,ZjB,0,φNA,NB(x0))Γi,bΓi,b]\displaystyle\frac{1}{N_{A}}\frac{1}{N_{B}}\sum_{i=1}^{N_{A}}\sum_{j=1}^{N_{B}}\begin{bmatrix}\psi_{s}^{2}\left(Y_{i}^{A},Y_{j}^{B},Z_{i}^{A},Z_{j}^{B},0,\varphi_{N_{A},N_{B}}(x_{0})\right)&\Gamma_{i,b}^{\intercal}\,\psi_{s}\left(Y_{i}^{A},Y_{j}^{B},Z_{i}^{A},Z_{j}^{B},0,\varphi_{N_{A},N_{B}}(x_{0})\right)\\ \Gamma_{i,b}\psi_{s}\left(Y_{i}^{A},Y_{j}^{B},Z_{i}^{A},Z_{j}^{B},0,\varphi_{N_{A},N_{B}}(x_{0})\right)&\Gamma_{i,b}\,\Gamma_{i,b}^{\intercal}\end{bmatrix}

as NA,NB+N_{A},N_{B}\rightarrow+\infty, x0=min{x[t¯,t¯]:C(x)=0}x_{0}=\min\{x\in[\underline{t},\overline{t}]:C(x)=0\} with C()C(\cdot) defined in (4.5).

Some remarks are in order.

Remark E.1.

The reason the set of active/binding inequalities in (5.2) enters the design effect is because they would enter the Taylor expansion of LUR,aux(x)LR,aux(x)L_{UR,\text{aux}}(x)-L_{R,\text{aux}}(x), and the inactive/slack inequalities do not because their Lagrange multipliers would be zero on account of complementary slackness.

Remark E.2.

The above procedure relies on consistent estimation of the set of active/binding inequalities in (5.2) through {Γ^i,b,iU}\{\hat{\Gamma}_{i,b},i\in U\}. Estimation of this set can be implemented, for example, using a generalized moment selection procedure as in Andrews and Soares (2010).

Remark E.3.

This procedure uses an asymptotic critical value, where justification of the asymptotic form of LRauxLR_{\text{aux}}, given by (E.11), is through an application of a central limit theorem. This asymptotic form of the test statistic is for a cone-based testing problem on a multivariate normal mean vector ν\nu:

0:ν×dim(Γi,b):νeq=0versus1:ν×dim(Γi,b).\displaystyle\mathcal{H}_{0}:\nu\in\mathbb{R}\times\mathbb{R}_{-}^{\text{dim}(\Gamma_{i,b})}:\nu_{eq}=0\quad\text{versus}\quad\mathcal{H}_{1}:\nu\in\mathbb{R}\times\mathbb{R}_{-}^{\text{dim}(\Gamma_{i,b})}. (E.12)