Un modelo tgarch con una distribución t de estudio asimétrica y las hipótesis de racionalidad de los inversionistas bursátiles en Latinoamérica

Abstract

We propose an ARCH model of the TGARCH type with an asymmetric Student's t distribution. It is built using the methodology of Fernandez and Steel (1998) and the traditional TGARCH model developed by Zakoian (1994). The model is used to describe series of stock market returns and to assess the validity of the rationality hypotheses in Latin America. The results suggest that: 1) The series can be described adequately with the proposed model; (2) the Samuelson´s rationality hypothesis is consistent with the evidence of the markets of Argentina, Brazil, Chile, Colombia and Mexico; 3) the traditional rationality hypothesis is consistent with the evidence of Peru; and (4) the volatility estimated with the proposed model are higher than those estimated with the traditional TGARCH model over the period 2008-2009.