Volatility contagion and market integration across major coal markets: A diagonal BEKK GARCH approach

Abstract

The present study attempts to meaningfully add to the existing strand of literature on coal market predictability by examining the level of market integration across three major coal export markets. Using a tri-variate diagonal BEKK GARCH framework, the study investigates the own-volatility persistence and cross-volatility contagion effects among European, Australian, and South African coal markets. The results validate the presence of strong volatility contagion among the three markets, indicating a high level of market integration. The contagion effect is observed to be heterogeneous across market pairs. Further, while the study finds convincing evidence for volatility clustering, the EGARCH results fail to affirm the presence of leverage effect among the returns series. In short, the study unveiled complex dynamics in the coal markets’ price generation mechanism that necessitates active portfolio management. As such, besides having significant policy implications, the study’s findings would be of pertinent interest to financial practitioners and investors who seek to diversify their portfolio through investments in global commodity markets.