5 IZA Policy Papers
IZA Policy Paper No. 182
IZA Policy Paper No. 131
Published in Portuguese Economic Journal, 2017, Volume 16, Nº 3.
IZA Policy Paper No. 29
based on the introduction to a special issue of: Economics of Education Review, 2011, 30 (6), 1118-1122
IZA Policy Paper No. 3
also available as OECD Social, Employment and Migration Working Paper