Analyzing Heterogeneous Stock Price Comovements Through Hybrid Approaches

This paper studies the hypothesis of stock price comovements between the US market and four different regions (the G6, the BRICS, the MENA (Middle East North Africa) during calm and crisis periods. Using different econometric approaches (BEKK-GARCH model, cointegration tests, and panel cointegration tests), we checked the interdependence of these markets in the short and the long term. Our findings point to the importance of heterogeneity linked to the stock price adjustment process, inviting individual analysis to be carried out according to market specificities in the aim of identifying countries that are sources of investment opportunities. We also highlighted the presence of time-varying stock price comovements that significantly increased after the subprime crisis. This enabled us to specify periods and regions that can still provide promising diversification benefits. Investigation of this issue is of interest for investors and bankers in order to improve their portfolio choices, diversification strategies as well as risk management.