4 IZA Discussion Papers
IZA Discussion Paper No. 13056
forthcoming in: Economic Journal
IZA Discussion Paper No. 10853
published in: World Development, 2019, 113, 186 - 203
IZA Discussion Paper No. 6324
revised version published in: Journal of Population Economics, 2013, 26 (2), 483-506
IZA Discussion Paper No. 1700
published in: E. Hanushek and F. Welch, eds., Handbook of the Economics of Education, North Holland: Amsterdam, 2006, 307-458