The aim of this project is to extend and improve an existing research infrastructure in order to stimulate new research dealing with population issues in a multi-disciplinary framework. These issues concern burning issues such as socioeconomic inequalities in family and health outcomes, immigrant integration, and new conditions for combining family and working life in modern society. Providing researchers from social sciences, humanities and medicine with high quality data opens up completely new possibilities to empirically address a range of important research questions. This requires both large scale digitization of data and the establishment of a user friendly system of data extraction and dissemination. The Scanian Economic-Demographic Database (SEDD) is an already well-developed data infrastructure, which has been the basis for a large body of international research connected to the Centre for Economic Demography at Lund University. The aim of the present project is to digitize and link information from income and taxation registers to the existing database. These registers contain annual information about occupation and income from various sources. Data is available at an individual level from about 1900 onwards. Adding this social and economic information to the mainly demographic data already available in SEDD, considerably increases the scientific value of the database by enabling studies of socioeconomic and demographic interactions in a long-term perspective.