4 IZA Discussion Papers
IZA Discussion Paper No. 8218
Revised version published in: Journal of Public Economics, 2015, 126, 74-85
IZA Discussion Paper No. 5556
IZA Discussion Paper No. 5204
revised version published in: European Economic Review, 2013, 60, 32-51
IZA Discussion Paper No. 1583
published in: Journal of the European Economic Association, 2012, 10 (3), 555-572