Since 2004 full professor of economics at the Schumpeter School of Economics, University of Wuppertal, Germany, 2003/ 2004 Visiting Scholar at Russell Sage Foundation, New York. Before, full professor of economics at Utrecht University, The Netherlands. He studied engineering and economics in Germany (Hamburg and Berlin), he has been a Senior Research Fellow at the Wissenschaftszentrum Berlin WZB) and was a guest professor and research fellow in the United States (Stanford University, University of California at Berkeley, Princeton University, NBER), The Netherlands (Tinbergen Institute, Amsterdam and The Netherlands Institute for Advanced Studies, Wassenaar), and Italy (Universities Bologna and Modena).
He has published 14 books and numerous journal articles. He also did consultant work among others for OECD, ILO, the European Commission, the European Parliament, the Federal Government of Germany, the German Bundestag.