First Author:   Daniel A. P. Uhr Applied Economics Post-Graduation Program. Federal University of Pelotas, Brazil. daniel.uhr@gmail.com   Rua Gomes Carneiro, nº 1, 4º Andar., Departamento de Economia da UFPel., Campus Porto. Pelotas, 96010-610, Brazil   +55 (53) 3921-1429(Phone) +55 (53) 3921-1429(Fax) https://sites.google.com/site/danieluhr/ Second Author: Julia G. Z. Uhr Applied Economics Post-Graduation Program. Federal University of Pelotas zierouhr@gmail.com         Third Author: Regis A. Ely Applied Economics Post-Graduation Program. Federal University of Pelotas regisaely@gmail.com         http://