In examining a number of important research questions related to the reform of the Social Security program, it is helpful to understand patterns of participation in the Disability Insurance (DI) program. DI beneficiaries comprise a large fraction, approximately 15 percent, of the pool of workers who receive Social Security benefits (Social Security Administration, 2001: Table 5.A16). They are a particularly vulnerable group in later life, with poverty rates more than twice as high as those for recipients of retirement or survivor benefits from Social Security (Thompson and Smith, 2002: Table A9-13c). Those who receive DI also have very different mortality experiences than those who do not (Zayatz, 1999), so careful modeling of the overlap between mortality and disability is essential when trying to determine the lifetime distributional consequences of Social Security reform. In addition, the larger disabled population, consisting of those who report work limitations but do not necessarily receive DI benefits, is also at higher risk of poverty and death than those who do not report work limitations. This research note explores these important intersections by presenting estimates from multivariate analyses of self-reported disability status, observed mortality, and reports of DI participation from administrative data. In our analyses, we use data from the 1990 through 1993 panels of the Survey of Income and Program Participation (SIPP) matched to the Social Security Administration's Summary Earnings Records (SER), Master Beneficiary Records (MBR), and Death Master File (from the Social Security number identification file, or Numident). Using administrative data allows us to improve upon several previous studies, as research consistently demonstrates that self-reports of earnings and disability benefit receipt are unreliable. Individuals often round up or down when reporting their earnings, particularly if they are asked about the distant past, and they frequently misreport social insurance and social assistance benefit types because they misunderstand the reasons that they receive benefits (see, for example, Huynh, Rupp, and Sears, 2002)
