4 IZA Discussion Papers
IZA Discussion Paper No. 4580
published in: IZA Journal of Labor Policy 2014, 3:21, https://doi.org/10.1186/2193-9004-3-21
IZA Discussion Paper No. 4509
revised version (including technical online appendix) published in: Journal of Applied Econometrics, 2013, 28 (7), 1153–1178
IZA Discussion Paper No. 3483
IZA Discussion Paper No. 469
published in: Journal of the European Economic Association, 2005, 3 (6), 1386-1417