PDR 30 supp Hauser/au/EPC/sp

Large-scale data collection has become the kernel of the growth of knowledge in the social sciences. Nowhere is this more evident than in research in the demography of aging and the life course, where scientific progress has been stimulated and sustained by complementary longitudinal studies of aging populations. In this chapter, we review the history, organization, and design of two of these public resources, the Wisconsin Longitudinal Study (WLS) and the Health and Retirement Study (HRS). Recent innovations in each of these studies hold promise for major advances in knowledge about the demography, economics, sociology, and epidemiology of aging. The stories of the WLS and HRS highlight important clues about the creation of systems of continuing surveys to inform science and public policy.