6 IZA Discussion Papers
IZA Discussion Paper No. 7280
IZA Discussion Paper No. 5907
published in: Perspectives on Global Development and Technology, 2014, 13, 347-378.
IZA Discussion Paper No. 4583
shortened version published in: Economics Letters, 2013, 118 (3), 482-484
IZA Discussion Paper No. 3822
published in: Economics Bulletin, 2009, 29 (3), 1846-1853
IZA Discussion Paper No. 2897
published in: Applied Economics, 2010, 42 (16), 2091-2098