1. Department of Economics and Business, Universitat Pompeu Fabra, 08002 Barcelona, Spain;
2. UPF Barcelona School of Management, 08008 Barcelona, Spain;
3. Barcelona School of Economics, 08005 Barcelona, Spain;
4. Max Planck Institute for Innovation and Competition, 80539 Munich, Germany;
5. Munich School of Management, Ludwig-Maximilians-University, 80539 Munich, Germany;
6. Centre for Economic Policy Research (CEPR), London EC1V 0DX, United Kingdom;
7. School of Business and Management, Queen Mary University of London, London E1 4NS, United Kingdom