3 IZA Discussion Papers
IZA Discussion Paper No. 5900
IZA Discussion Paper No. 4884
published in: Journal of Political Economy, 2010, 118 (4), 723-746
IZA Discussion Paper No. 3855
published in: Jahrbücher für Nationalökonomie und Statistik, 2012, 232 (1), 4 - 11