523 IZA Discussion Papers
IZA Discussion Paper No. 670
published in: Journal of the European Economic Association, 2007, 5 (5), 885-926,
IZA Discussion Paper No. 498
published in: Canadian Journal of Economics, 2009, 42 (4), 1326 - 1346
IZA Discussion Paper No. 419
published in: Journal of Human Resources, 2004, 39 (3), 649-674