4 IZA Discussion Papers
IZA Discussion Paper No. 17494
IZA Discussion Paper No. 16214
IZA Discussion Paper No. 10072
revised version published in: Journal of Applied Econometrics, 2019, 34, 707-72
IZA Discussion Paper No. 7135
revised version published in: European Journal of Population, 2014, 30 (1), 35-63