324 IZA Discussion Papers
IZA Discussion Paper No. 3444
published in: Labour Economics, 2009, 16 (6), 638-647
IZA Discussion Paper No. 3432
published in: Journal of Human Resources, 2012. 47(4), 913-950.
IZA Discussion Paper No. 2787
revised version published in: Education Economics, 2010, 18(1), 111-123
IZA Discussion Paper No. 1656
published in: Higher Education, 2007, 54 (5), 647-663