3 IZA Discussion Papers
IZA Discussion Paper No. 7070
published in: American Economic Review: Papers & Proceedings, 2013, 103 (3), 99-104
IZA Discussion Paper No. 3442
published in: International Economic Review, 2012, 53 (2), 511 - 538
IZA Discussion Paper No. 702
published in: American Economic Review, 2003, 93 (2), 57-62