6 IZA Discussion Papers
IZA Discussion Paper No. 7873
IZA Discussion Paper No. 6779
IZA Discussion Paper No. 5337
revised version published in :Labour Economics, 2012, 19 (5), 729-737
IZA Discussion Paper No. 3620
IZA Discussion Paper No. 2854
IZA Discussion Paper No. 1300
Published as: 'The Threat Effect of Active Labour Market Programmes' in: Scandinavian Journal of Economics, 2008, 110 (2), 385 - 401