4 IZA Discussion Papers
IZA Discussion Paper No. 7280
IZA Discussion Paper No. 7241
IZA Discussion Paper No. 6115
published in: Applied Economics Letters, 2012, 19 (17), 1663-1665
IZA Discussion Paper No. 3451
revised version based on DP 2328 and DP 3451 published as "Taxing education in Ramsey's tradition" in: Journal of Public Economics, 2009, 93 (11-12), 1254-1260