44 IZA Discussion Papers
IZA Discussion Paper No. 4007
published in: Oxford Bulletin of Economics and Statistics, 2012, 74 (5), 646 - 675
IZA Discussion Paper No. 3540
revised version published in: Empirical Economics, 2013, 44(1), 289-328
IZA Discussion Paper No. 1576
published in: European Journal of Population, 2011, 27 (1), 1 - 32