144 IZA Discussion Papers
IZA Discussion Paper No. 1412
published in: Economics of Education Review, 2008, 27 (1), 1-13
IZA Discussion Paper No. 1164
IZA Discussion Paper No. 1122
published in: Review of Economics and Statistics, 2007, 89 (4), 721-736
IZA Discussion Paper No. 733
published in: Brussels Economic Review / Cahiers Economiques de Bruxelles, 2004, 47 (3), 387-408