2 IZA Discussion Papers
IZA Discussion Paper No. 7328
published in: Journal of Population Ageing, 2013, 6 (3), 227-246
IZA Discussion Paper No. 3842
published as 'With or Without U? Testing the Hypothesis of an Inverted U-Shaped Union Membership-Age Relationship' in: Contemporary Economics, 2012, 6 (4), 28-34