First Author:   Valdeir Monteiro CAEN Graduate School of Economics (UFC), Brazil valdeir.smonteiro@alu.ufc.br         Second Author: Paulo Matos CAEN Graduate School of Economics (UFC) and Fiscal Monitor (TCE/CE), Brazil paulomatos@caen.ufc.br         Third Author: Cristiano Silva Center of Agrarian Sciences (UFC), Brazil cristiano.dacostadasilva@hotmail.com