First Author:   Marcelo Mello Virginia Tech, and Faculdades IBMEC\RJ, Brazil mmello@vt.edu   3016 Pamplin Hall (0316) Blacksburg, 24061, United States   540-231-7958(Phone) 540-231-7958(Fax) Second Author: Roberto Guimaraes-Filho International Monetary Fund RGuimaraes@imf.org   WHD, International Monetary Fund, 700 19th st., N.W. Washington, D.C., 20431, U.S.   202-623-1686(Phone)