Redes Bayesianas: um método para avaliação de interdependência e contágio em séries temporais multivariadas / Bayesian Networks: a method for evaluation of interdependence and contagion in multivariate time series

AUTOR(ES)
DATA DE PUBLICAÇÃO

2011

RESUMO

This work aims to identify the existence of financial contagion using a metodology of Bayesian networks. Besides Bayesian networks, the analysis of the international marketsinterdependence in times of financial crises, occurred between 1996 and 2009, was modeled using two other techniques - multivariate GARCH models and Copulas models, involving countries in which its effects were possible to assess and which were subject to similar studies in the literature. With well-defined crisis periods and a metodology based on graph theory and Bayesian inference, a sequential analysis was executed, in which the realities preceding periods of crisis were considered to be prior situations to the events (likelihood). From this combination results the new posterior reality, which serves as a prior to the subsequent period and so on. The results pointed to a large interconnection between markets and several evidences of contagion in times of financial crises, with well-defined responsibles and highly supported by the literature. Moreover, the pairs of countries that show evidence of financial contagion by Bayesian networks in over periods of crises were the same as that presented the highest values of the parameters estimated by copulas and the most strongly significant parameters in the multivariate GARCH model. Thus, the results obtained by Bayesian networks become more relevant, suggesting good adherence of the model to the data set used in this study. Finally, it was found that after the various crises, the markets were much more connected.

ASSUNTO(S)

bayesian networks contágio financeiro copulas cópulas financial contagion garch multivariado interdependence interdependência multivariate garch redes bayesianas

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