The purpose of this project is to maintain, update and substantially expand the internationally renowned Social Policy Indicators (SPIN) Database (www.sofi.su.se/spin). The new improved SPIN database will continue to offer unique possibilities for state-of-the-art analyses on the causes and consequences of welfare states and social policy that are difficult to obtain elsewhere. The SPIN database includes a wide range of institutional indicators on the financing, eligibility criteria and quality of various types of social policy programs. The SPIN database has now reached the stage of development where new resources are required to continue pioneer welfare state analyses, improve dissemination of data and contribute to new breakthroughs in research. We have successfully finished a number of pilot projects on the conceptualization and measurement of social policy in areas where new data are urgently needed. In the continued development of the SPIN database, we will not only update existing data. Based on our pilot projects, we will construct new SPIN data models. We will also initiate new pilot projects to continue push further the frontiers of welfare state research, as well as improve the web interface and dissemination of SPIN. No Swedish government agency are responsible for collecting similar comparative data as in SPIN. SPIN does not include any ethically sensitive individual level data.