This is an application for a five-year competing renewal of a Population Research Center Core Grant to the Center of Demography and Ecology (CDE) at the University of Wisconsin-Madison. CDE is a multi-disciplinary faculty research cooperative for social scientific demographic research whose membership includes sociologists, rural sociologists, economists, and historians. CDE provides research support through four Cores: administration, data processing, data library and print library. Current and planned research activities of CDE focus on population composition and distribution within the United States, especially on changes in family structure and process and social inequality, but the total range of research and training activities of CDE members is far broader in content and scope. CDE activities include about 35 research projects that have either been approved for access to the Center's core facilities or are proposed for core usage in the present application. In addition to these projects, CDE has NICHD support for predoctoral and postdoctoral training in population, NIA support for predoctoral training, and an NIA Center Grant Supplement for new research initiatives in the demography of aging. CDE members typically have overlapping memberships in cooperating research and training units, which include their academic departments, the Institute of Aging and Adult Life, the Institute for Research on Poverty, the Ap[plied Population Research Laboratory, and the Letters and Sciences Survey Research Laboratory. CDE has been and plans to remain a leader in efficient management and analysis of large, complex demographic data files, as well as to provide highly effective research support for a broad variety of approaches to demographic research. This is made possible with core support from NICHD in addition to financial support from the University of Wisconsin and other sources. With this proposal we seek to maintain current core support capabilities, including an infrastructure for centralized archival storage and retrieval, combined with distributed data processing using a variety of computer platforms, that will continue to improve our capability to manage and analyze our ever growing holdings of domestic and international data.