Rafael Costa lima University of São Paulo   Av. Prof. Luciano Gualberto, 908, FEA 2, sala 217 Cidade Universitária São Paulo, SP 05448010 Brazil   rafaelcostalima@usp.br   http://www.fea.usp.br/feaecon//           JEL Areas: D7 : Analysis of Collective Decision-Making: General D8 : Information, Knowledge, and Uncertainty: General