3 IZA Discussion Papers
IZA Discussion Paper No. 4895
IZA Discussion Paper No. 888
revised version published in: Economics Letters, 2005, 88 (1), 79-84
IZA Discussion Paper No. 665
revised version published as 'Fancy a stay at the 'Hotel California'? in: Kyklos, 2005, 58 (4), 519-535