5 IZA Discussion Papers
IZA Discussion Paper No. 3306
IZA Discussion Paper No. 2315
IZA Discussion Paper No. 1936
published in: Public Choice, 2010, 144 (1), 215–238
IZA Discussion Paper No. 1431
published in: Journal of Population Economics, 2007, 20 (3), 495 - 526
IZA Discussion Paper No. 1043