1. The Spanish National Research Council (CSIC), 28037 Madrid, Comunidad de Madrid, Spain
2. Max Planck Institute for Research on Collective Goods, Kurt-Schumacher-Str. 10, 53113 Bonn, Germany
3. Department of Sociology, University of Zürich, 8050 Zurich, Switzerland
4. MZES, University of Mannheim, 68159 Mannheim, Baden-Württemberg, Germany