1. Nockherstraße 2, 81541 Munich Research Associate at the German Youth Institute (DJI), , Germany
2. University of Mannheim Professor of Statistics at the Institute for Employment Research (IAB), Regensburger Str. 104, 90478 Nuremberg, Germany, the Ludwig-Maximilian University of Munich, Germany, and the , Germany
3. University of Manchester Alexandru Cernat is an Associate Professor of Social Statistics at the School of Social Sciences, , Humanities Bridgeford Street 2.13N, Manchester M13 9PL, UK