This application requests R24 infrastructure support for the California Center for Population Research (CCPR). With 75 faculty affiliates in 20 departments and 12,620 sq. ft. of new space, CCPR's central goal is to initiate and support interdisciplinary research on the most important basic science and policy questions in population studies. To accomplish this goal, CCPR: (1) trains and supports junior population researchers and expands the skills of researchers at all levels, (2) creates an environment in which interdisciplinary interaction and collaborative research is the norm, (3) provides high quality services that increase the pace, impact, and efficiency of research, (4) encourages the development and use of innovative research methods and approaches, (5) provides access to population data and supports the collection of new data when needed, and (6) disseminates CCPR research and data to a variety of audiences. Five signature themes characterize CCPR research now and over the next five years: 1. Contemporary Family and Household Dynamics; 2. Neighborhoods Dynamics and Individual Welfare; 3. Inequality and Social/Economic Mobility; 4. Social Dimensions of Health; and 5. Life Cycle and Long Term Changes. We request funding for four research support cores and one developmental infrastructure core over the next five years. The cores are: 1. Administrative Core; 2. Computing Core; 3. Statistics and Methods Core; 4. Information Core; and 5. Development Core. The goals of these cores are, respectively, 1. To prioritize and coordinate all CCPR activities and build an interdisciplinary research community; 2. To provide a computing environment for CCPR research and cores; 3. To support CCPR research and training by providing expertise in statistical methodology; 4. To disseminate information and data among CCPR affiliates and the broader research community; 5. To foster innovative and interdisciplinary population research projects.