145 IZA Discussion Papers
IZA Discussion Paper No. 1150
published in: Journal of Human Resources, 2006, 41 (4), 841-868
IZA Discussion Paper No. 1064
IZA Discussion Paper No. 674
published in: Review of Income and Wealth, 2006, 51 (1), 17-42
IZA Discussion Paper No. 585
revised version published in: American Economic Review, 2005, 95 (5), 1653-1672
IZA Discussion Paper No. 432
published in: Southern Economic Journal, 2004, 71 (2), 397-417