1. IMPA – Instituto de Matemática Pura e Aplicada Rio de Janeiro RJ Brazil
2. EPGE FGV – Fundação Getúlio Vargas Rio de Janeiro RJ Brazil
3. Department of Economics University of São Paulo São Paulo SP Brazil
4. Graduate School of Economics Federal University of Goiás Goiânia GO Brazil
5. Department of Mathematics Brooklyn College of the City University of New York New York
6. Department of Mathematics The Graduate Center of the City University of New York New York
7. Department of Mathematics Faculty of Science, University of Porto Porto Portugal
8. LIAAD – INESC TEC Faculty of Science, University of Porto Porto Portugal