Since the last review of NICHD, the Population Studies Center has strengthened its traditional research areas while expanding rapidly in new directions. There has been substantial growth in the Center's international work and in interdisciplinary research on domestic social and policy aspects of the population. The dollar volume of funded research at the Center has grown by about 50% since the last competitive review by NICHD. These advances have not gone unnoticed by the University, which has increased institutional support for the Center over the past five years. Developments in computing have facilitated research and will facilitate it further in the next period. Non-NICHD funding will allow the Center to obtain the hardware necessary to develop a state-of-the-art computing environment that will combine a network of powerful desktop workstations with extensive on-line data archives. NICHD is being asked for funds for the personnel, software, and maintenance necessary to make this system maximally useful to Center researchers. The Data Processing, Data Archive, and Library Cores are directly involved in making this system a national model for social science research. In the renewal period, we request that the six existing cores - Administrative, Publications, Library, Data Processing, Data Archive, and Statistical Consulting - be maintained and strengthened, commensurate with the growing volume of research and the special demands of new international and interdisciplinary projects. We plan to meet our needs in a cost-effective manner. Our senior support staff are highly experienced and among the best in the field. To lessen the new demands on our highly qualified and experienced senior support staff, we plan to add a few highly-trained support staff members, and also some lower-level staff who will handle routine matters. We also plan to improve our cores so that researchers can obtain more of the assistance that they require on their own. One example is increased computerization and integration of the holdings of the Data Archive and the Library. Although well-trained staff members are available to help, the researcher can obtain answers to many questions at any hour of the day or night by consulting established files.