Professor	School of Economics and Finance, University of St Andrews
Research Fellow	Centre for Economic Policy Research (Labour Economics)
Research Fellow	Institute for the Study of Labor (IZA), Bonn
Research Fellow	CESifo, Munich
Research Fellow	Centre for Research and Analysis of Migration (CReAM), University College, London
Mitglied	Ausschuss für Bevölkerungsökonomik, Verein für Sozialpolitik
Research Fellow	RWI Research Network, Essen
Research Fellow	Handa Centre for the Study of Terrorism and Political Violence, University of St Andrews
Professor Emeritus	Ph.D. Program in Economics, Graduate Center, City University of New York
Fakultätsmitglied	WiSo Fakultät, Universität zu Köln