104 IZA Discussion Papers
IZA Discussion Paper No. 614
published in: Scottish Journal of Political Economy, 2005, 52 (2), 177-193
IZA Discussion Paper No. 426
revised version published in: Labour Economics, 2007, 14(6), 926-937
IZA Discussion Paper No. 390
IZA Discussion Paper No. 48
published in: Scottish Journal of Political Economy, 1999, 46 (4), 419-436