The goal of the Core is to foster national and international collaboration on survey research in aging. The Core continues a long-standing Michigan tradition of outreach to developing countries in Asia, Africa, and Latin America, and builds on more recent activities in developed countries and the U.S. The core leader, Mary Beth Ofstedal, has extensive experience analyzing data on health and aging from several Asian countries and is Co-Investigator on the Health and Retirement Survey. Activities that are proposed include: A formal network that will focus on disability trends, primarily in the United States but with international comparisons where possible. The broad objective of the Disability Trends Network is to accelerate scientific advancement of our understanding of old-age disability trends. The network will focus on three areas: 1) updating trends and reconciling differences across studies, including international comparisons; 2) determining the causes of the trends; and 3) articulating the implications of the trends. The network will be led by Robert Schoeni and will involve investigators from around the U.S. who will communicate and disseminate via a dedicated web site, meet once a year, and aim for a coordinated publication on disability trends as a special issue of a high-profile journal. Several international networks that will focus on survey design and comparative analysis on aging in developed and developing countries around the world: HRS/ELSA/SHARE; South Africa/Africa; Developing Countries Comparative; AIDS and older persons; Nepal; Developmental Idealism. Specific activities will include identification of members, conference calls, face-to-face meetings and working visits to explore specific topics. Network leaders will coordinate with the international comparative data resource project that is proposed in another Core.