103 IZA Discussion Papers
IZA Discussion Paper No. 1373
published in: Industrial and Labor Relations Review, 2007, 60 (2), 163-186
IZA Discussion Paper No. 756
published in: Industrial and Labor Relations Review, 2006, 59 (2), 243-266
IZA Discussion Paper No. 524
revised version published in: Annales D'Économie et De Statistique, 2004, 71-72, 293-315