Acknowledgments: The authors would like to thank William Encinosa, Izabela Jelovac, Inés Macho- Stadler, David Pérez-Castrillo, two anonymous referees and the Editor for their comments and suggestions. We greatly benefited from comments by Javier Hernández on the Spanish MUFACE case. Any remaining errors are the authors’ responsibility. Vera acknowledges financial support by a Marie Curie Fellowship under contract no. HPMF-CT-01206. Olivella acknowledges financial support from projects SEJ2006- 00538, ECO2009-7616, Consolider-Ingenio CSD2006-16, 2009SGR-169, and Barcelona Economics- Xarxa CREA. Olivella is a Research Fellow of MOVE (Markets, Organizations and Votes in Economics). 

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