First Author:   Flavio V Vieira Federal University of Uberlandia flaviovieira@ufu.br   Av. Joao Naves de Avila 2121 Uberlandia, 38400902, Brazil   +5534996932585(Phone) +5534996932585(Fax) http://www.ieri.ufu.br/ Second Author: Cleomar Gomes da Silva Institute of Economics, Federal University of Uberlandia and CNPq Associate Researcher, Brazil cleomargomes@gmail.com   Av Joao Naves de Avila 2121, Instituto de Economia, Universidade Federal de Uberlandia Uberlandia, 38400902, Brazil   +553432162585(Phone)   http://www.ie.ufu.br