Martin Werding Chair in Social Policy and Public Finance, Ruhr-University Bochum   Ruhr-University Bochum Faculty of social science Universitätsstraße 150 Bochum, 44801 Germany   martin.werding@ruhr-uni-bochum.de   http://www.sowi.rub.de/sozialpolitik/oekonomik           JEL Areas: H : Public Economics J : Labor and Demographic Economics