3 IZA Discussion Papers
IZA Discussion Paper No. 8746
published in: World Development, 2015, 65, 6 - 26
IZA Discussion Paper No. 4204
published in: Journal of Human Resources, 2011, 46 (2), 261 - 294
IZA Discussion Paper No. 4148
published in: International Journal of Manpower, 2010, 31 (2), 138-162