Volatility Spillovers between Spot and Futures Markets: An Empirical Study on U.S. Agricultural Commodities

Abstract

In well-established and matured agricultural commodity futures market, like U.S., the futures markets are expected to serve as a central exchange for both domestic and international information and thus function as a primary mechanism for price discovery and reduce price variability through hedging activities. After having outlined the present status of U.S. agricultural commodities market, a comprehensive study on the volatility spillover between the spot and futures markets of 12 agricultural commodities is carried out to understand the dynamics of volatility factors which hinder the efficiency of those markets, by comparing two different time periods which stand different by various economical and market conditions, for arriving at relative conclusions. The Granger Causality Test results on the direction of flow of volatility between the spot and futures market shows that in majority of the commodities (6 commodities during 1995-2005 & 7 commodities during 2006-2011) there were unidirectional flow of from futures to spot markets, meaning that futures markets has significantly contributed to the volatility of spot market. There were bidirectional relationship in 5 commodities in 1995-2005 & 3 commodities in 2006-2011. This shows that due to information flow from both sides, spot to future markets and future market to spot market, both were equally responsible for causing volatility. Overall there is no evidence of abnormal volatility in the sub-period 2006-2011, compared to1995-2005. Abnormality of non-directional flow is identified in CBOT wheat during 2005-2011 which means that factors beyond futures market were responsible. Whereas, from the GARCH (1, 1) results, in terms of volatility, there is volatility clustering and persistence throughout the study period, with no abnormality during post 2006 period alone. To be specific, we show that volatility in U.S. agricultural commodities markets were prevalent during 1995-2005 and during 2006-2011, which experienced price spikes and price distortions. Hence, we conclude that huge in-flow of funds into the agricultural commodity futures market since 2006 is not the reason for volatility in US agricultural commodity market.