43 IZA Discussion Papers
IZA Discussion Paper No. 962
published in: German Economic Review, 2004, 5(4), 481-504
IZA Discussion Paper No. 708
published in: Socio-Economic Review, 2005, 3 (1), 1-24
IZA Discussion Paper No. 707
published in: Applied Economics Quarterly, 2003, 49 (3), 213-232