5 IZA Discussion Papers
IZA Discussion Paper No. 15463
IZA Discussion Paper No. 9892
published in: Social Indicators Research, 2018, 138 (2), 505 - 522
IZA Discussion Paper No. 7603
IZA Discussion Paper No. 6449
revised and updated version published in: Regional Studies, 2017, 51 (7), 1100-1114
IZA Discussion Paper No. 2703
substantially revised version published in: Journal of Development Economics, 2010, 92(2), 215-231