Tatsuyoshi Okimoto

New Evidence of Asymmetric Dependence Structures in International Equity Markets

A number of recent studies finds two asymmetries in dependence structures in international equity markets; specifically, dependence tends to be high in both highly volatile markets and in bear markets. In this paper, a further investigation of asymmetric dependence structures in international equity markets is performed by using the Markov switching model and copula theory. Combining these two theories enables me to model dependence structures with sufficient flexibility. Using this flexible framework, I indeed find that there are two distinct regimes in the U. S.-U. K. market. I also show that for the U. S.-U. K. market the bear regime is better described by an asymmetric copula with lower tail dependence with clear rejection of the Markov switching multivariate normal model. In addition, I show that ignorance of this further asymmetry in bear markets is very costly for risk management. Lastly, I conduct a similar analysis for other G7 countries, where I find other cases in which the use of a Markov switching multivariate normal model would be inappropriate.

Do socially responsible investment indexes outperform conventional indexes

The question of whether more Socially Responsible (SR) firms outperform or underperform other conventional firms has been debated in the economic literature. In this study, using the Socially Responsible Investment (SRI) indexes and conventional stock indexes in the US, the UK and Japan, first and second moments of firm performance distributions are estimated based on the Markov Switching (MS) model. We find two distinct regimes (bear and bull) in the SRI markets as well as the stock markets for all the three countries. These regimes occur with the same timing in both types of market. No statistical difference in means and volatilities generated from the SRI indexes and conventional indexes in either region was found. Furthermore, we find strong comovements between the two indexes in both the regimes.

Increasing Trends in the Excess Comovement of Commodity Prices

We investigate how the excess comovement of commodity prices, that is, the correlation in commodity returns after filtering out common fundamental shocks, has changed over the past three decades by developing the smooth-transition dynamic conditional correlation model that can capture long-run trends and short-run dynamics of correlation simultaneously. Using data from 1983 to 2011, we find that significant increasing longrun trends in excess comovement have appeared since around 2000. We confirm that these increasing trends are neither an artifact of the financial crisis after the bankruptcy of Lehman Brothers in September 2008 nor the time-varying sensitivities of commodity returns to common fundamental shocks. Moreover, we find that no significant increasing trends exist in the excess comovement among off-index commodities and that the surge of global demand alone cannot explain the increasing trends. These findings provide additional evidence for the timing and scope of the recent increasing commodity-return correlations that suggest the influence of the financialization of commodity markets starting around 2000.

Trends in Stock-Bond Correlations

ABSTRACT Previous studies document the existence of long-run trends in comovements in the stock and bond markets. Following these findings, this article examines possible trends in stock-bond return correlations. To this end, we introduce a trend component into a smooth transition regression (STR) model including the multiple transition variables of Aslanidis and Christiansen (2012). The results indicate the existence of significant decreasing trends in stock-bond correlations for many advanced safer countries. In addition, although stock market volatility continues to be an important factor in stock-bond correlations, the short rate and yield spread become only marginally significant once we introduce the trend component. Our out-of-sample analysis also demonstrates that the STR model, including the volatility index and time trend as the transition variables, dominates other models. Furthermore, we find a significant increase in stock-bond correlations for riskier euro countries around the beginning of the euro crisis. Our findings of decreasing and increasing trends in stock-bond correlations can be considered a consequence of the decreasing effects of diversification and more intensive flight-to-quality behaviour that have taken place in recent years and after the euro crisis.

Asymmetric Increasing Trends in Dependence in International Equity Markets

This paper investigates asymmetric increasing trends in dependence in major international equity markets. To this end, we develop a multiple-regime smooth-transition copula GARCH model and address several important questions, including the number of regimes and the existence of increasing asymmetric trends in dependence. Our results suggest that two or three regimes are sufficient for describing the dependence trends in international equity markets over the last 35 years with significant asymmetric increases. In addition, the implied time-series of three dependence measures show a wide variety of dynamics, demonstrating the usefulness of our framework to describe asymmetric increasing dependence trends. Finally, we evaluate the economic significance of our empirical finding based on the 99% value at risk and expected shortfall. Our result indicates that both risk measures have increased approximately 20% over the last 35 years in major equity markets.