4 IZA Discussion Papers
IZA Discussion Paper No. 16033
IZA Discussion Paper No. 6123
published in: Canadian Public Policy/Analyse de Politiques, 2014, 40 (4), 377-390
IZA Discussion Paper No. 5258
published in: Journal of Human Capital, 2013, 7 (2), 161-189
IZA Discussion Paper No. 716
published in: Journal of Applied Econometrics, 2009, 24 (2), 338-365.