6 IZA Discussion Papers
IZA Discussion Paper No. 13559
IZA Discussion Paper No. 13558
IZA Discussion Paper No. 10197
IZA Discussion Paper No. 6378
published in: Journal of Public Economics, 2014, 117, 39-49
IZA Discussion Paper No. 3779
IZA Discussion Paper No. 234
published in: Schmollers Jahrbuch: Zeitschrift für Wirtschafts- und Sozialwissenschaften / Journal of Applied Social Science Studies, 2001, 121 (3), 53-406