Inference with Survey Data Having Nonignorable Nonresponse

大多数调查中都存在项目无反应，无反应率通常是可观的。如果非响应仅与观测数据有关，则可以忽略；否则，它是不可忽略的。对不可忽略的非响应的研究还远未完成。本研究的重点是统计估计和推断在横断面或纵向调查与不可忽视的无反应。将发展对诸如人口总数和分位数等参数的近似无偏和一致的调查估计量的方法。此外，还将研究估计器的有效性和鲁棒性。将努力研究多变量或纵向调查数据，以及在主要调查变量和协变量中存在的无响应问题。该研究者还将研究有效估计量的方差估计，使用线性化、替代、复制或重采样等方法，如折刀法、平衡半样本法、随机分组法和自举法。许多统计机构和政府机构通过调查收集数据。在大多数这些调查中，通常会有人不回应调查，或者给出部分答案；这种情况被称为无反应。不回应通常与不回应有关；例如，25岁以下的男性比年龄较大的男性更有可能没有反应。在这种情况下，统计方法没有得到很好的发展。研究者计划研究在各种类型的调查中存在无反应时的估计和推断方法。为了提高估计器的精度，将努力使用所有观察到的数据，利用辅助信息，并对调查数据的无反应率和/或分布进行统计建模。评估所导出的估计量的变异性的方法也将被研究。由于大多数拟议的研究课题都是由诸如人口普查局、劳工统计局、西部统计局和加拿大统计局等调查机构的问题所驱动的，因此拟议研究的结果将对这些调查机构处理无回应的方法产生重大影响。

Item nonresponse exists in most surveys and nonresponse rates are often appreciable. Nonresponse is ignorable if it is related to the observed data only; otherwise, it is nonignorable. Research for nonignorable nonresponse is far from complete. This investigator focuses on statistical estimation and inference in cross-sectional or longitudinal surveys with nonignorable nonresponse. Methods for deriving approximately unbiased and consistent survey estimators for parameters such as population totals and quantiles will be developed. In addition, the efficiency and robustness of estimators will also be studied. Effort will be made to study multivariate or longitudinal survey data, and problems with nonresponse in not only the main survey variables but also the covariates. This investigator will also study variance estimation for valid estimators, using methods such as linearization, substitution, replication or resampling such as the jackknife, the balanced half samples, the random groups, and the bootstrap.Many statistical and government agencies collect data through surveys. In most of these surveys, there are typically people who do not respond to the survey, or give partial answers; such cases are called nonresponses. Often a nonresponse is related to the nonrespondent; for example, males under the age of twenty-five years may be more likely not to respond than older males. In this case, the statistical methodology is not well developed. The investigator plans to study methods for estimation and inference in the presence of nonresponse for various types of surveys. To increase the precision of estimators, effort will be made to use all observed data, to utilize auxilliary information, and to statistically model the nonresponse rate and/or distribution of the survey data. Methods of assessing the varibility of the derived estimators will also be studied. Since most of the proposed research topics are motivated by problems in survey agencies such as the Census Bureau, the Bureau of Labor Statistics, Westat, and Statistics Canada, results obtained from the proposed research will have significant impacts on the methodology for handling noresponse in these survey agencies.