5 IZA Discussion Papers
IZA Discussion Paper No. 16949
IZA Discussion Paper No. 16245
IZA Discussion Paper No. 14084
IZA Discussion Paper No. 8961
published in: American Economic Journal: Applied Economics, 2016, 8 (2), 1-34
IZA Discussion Paper No. 924
combined with IZA DP 925 published in: Review of Economics of the Household, 2010, 8 (1), 105–146