183 IZA Discussion Papers
IZA Discussion Paper No. 603
published in: International Journal of Manpower, 2004, 25 (8), 688-713
IZA Discussion Paper No. 485
published in: European Economic Review, 2006, 50 (3), 695-736
IZA Discussion Paper No. 465
revised version published in: Economic Journal, 2006, 116 (513), 659-679