3 IZA Discussion Papers
IZA Discussion Paper No. 4371
published in: El Trimestre Económico, 2011, 78 (2), 343-375
IZA Discussion Paper No. 2901
revised version published in: European Economic Review, 2008, 52 (7), 1275 - 1311
IZA Discussion Paper No. 144
published in: Jonas Agell, Michael Keen and Alfons Weichenrieder (eds.), Labor Market Institutions and Public Regulation, 2004, 101-122