Jennifer R. Tennant

This chapter discusses the conceptual and practical challenges of measuring the prevalence of debilitating declines in health in the population. The main theme of the discussion is that decisions about measurement can have a significant impact on estimates of the size and composition of the population affected. Importantly, the analysis reveals that no single question or measure available in national representative data sources captures everyone currently targeted by public policies for those with disabilities. Best practice for researchers then requires researchers use multiple measures to study how declines in health affect employment, income, and public benefit receipt.

The purpose of this study is to examine the implications of using different approaches to estimating the U.S. working-age population with disabilities. The approaches compared are the traditional work-activity limitation question, the Census Bureau’s newer six-question sequence that does not include a work-activity limitation question, and the combination of the two. With data from the Current Population Survey and the American Community Survey, the authors demonstrate that using the work-limitation question or the six-question sequence alone results in an underestimate of the size of the working-age population with disabilities (assuming the International Classification of Disability, Health, and Functioning conceptualization of disabilities). Furthermore, the authors show that using the sample of the working-age population with disabilities identified by the six-question sequence will lead to biased estimates of key social policy success parameters; in particular, it will overestimate their employment rates and underestimate the share that are receiving Social Security Disability Insurance or Supplemental Security Income-Disabled Adults benefits relative to the broader sample that includes a work-limitation question and the six-question sequence.