383 IZA Discussion Papers
IZA Discussion Paper No. 24
published in: Wirtschaftsdienst, 1998, 78 (11), 652-653
IZA Discussion Paper No. 15
published in: Applied Economics Quarterly, 2004, 50 (4), 329–362
IZA Discussion Paper No. 10
published in: Journal of Population Economics, 1999, 12 (3), 363-389