383 IZA Discussion Papers
IZA Discussion Paper No. 927
published in: Journal of the European Economic Association, 2004, 2 (2-3), 216-228
IZA Discussion Paper No. 897
published in: Econometrica, 2004, 72 (3), 747-780
IZA Discussion Paper No. 344
published in: Journal of Population Economics, 2004, 17 (1), 117-131, revised version available here