René Cabral EGADE Business School and Banco de México   Ave. Rufino Tamayo Garza García, NL 62849 México   rcabral@tec.mx   http://homepages.mty.itesm.mx/rcabral/           JEL Areas: E5 : Monetary Policy, Central Banking, and the Supply of Money and Credit: General C5 : Econometric Modeling: General