43 IZA Discussion Papers
IZA Discussion Paper No. 1028
published in: El Trimestre Economico, 2010, 302 (2)
IZA Discussion Paper No. 909
published in: Economic Journal, 2007, 117 (518), 375-398
IZA Discussion Paper No. 543
published in: Southern Economic Journal, 2008, 75 (1), 91-103