1. VU Amsterdam, The Netherlands
2. René Bekkers, The Royal Netherlands Academy of Arts and Sciences (KNAW)—Van der Gaag Stichting Extraordinary Professor Social Aspects of Prosocial Behavior, Center for Philanthropic Studies, VU Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands, Mark Ottoni–Wilhelm, Department of Economics, IUPUI and Indiana University Lilly Family School of Philanthropy, USA,. Authors are listed in alphabetical order as both contributed equally to the paper.
3. IUPUI and Indiana University, USA