4 IZA Discussion Papers
IZA Discussion Paper No. 7199
revised version published in: American Economic Journal: Macroeconomics, 2015, 7 (3), 189-225
IZA Discussion Paper No. 2905
see IZA DP 7199 for a substantially revised and extended version
IZA Discussion Paper No. 2446
revised version published in: Annales d'Economie et de Statistique, 2010, 97/98, 207 - 234
IZA Discussion Paper No. 585
revised version published in: American Economic Review, 2005, 95 (5), 1653-1672