3 IZA Discussion Papers
IZA Discussion Paper No. 8827
published in: American Economic Review, 2015, 105 (5), 74–79
IZA Discussion Paper No. 8424
published in: Economic Journal, 2015,125 (583), 403–409
IZA Discussion Paper No. 2760
published in: Canadian Journal of Economics, 2007, 40 (3), 715-733