1. Kiel Institute for the World Economy, Kiellinie 66, 24105 Kiel, Germany (email: )
2. Paris School of Economics, University Paris 1 Panthéon-Sorbonne, and Migration Policy Center, European University Institute, 116-112 Bd de l'Hôpital, 75013 Paris, France (email: )
3. University of Munich, Ludwigstraße 33/III, 80539 Munich, Germany, IZA, and IFW Kiel (email: )
4. Kiel Institute for the World Economy, Kiellinie 66, 24105 Kiel, Germany, CEPR, and CESifo (email: )