6 IZA Discussion Papers
IZA Discussion Paper No. 10883
IZA Discussion Paper No. 5980
published in: Economic Journal, 2013, 123 (571), 831-874
IZA Discussion Paper No. 2643
IZA Discussion Paper No. 1959
published in: Oxford Review of Education, 2008, 34(1), 21-38
IZA Discussion Paper No. 1854
substantial revision published as 'On the efficiency costs of de-tracking secondary schools in Europe" in: Education Economics, [iFirst]
IZA Discussion Paper No. 995
published in: L. Woessmann and P. Petersen (eds.), Schools and the Equal Opportunity Problem, MIT 2007, 129-156