Date Added: Jan 2011
This paper introduces a non linear model for commodity futures prices which accounts for pressures due to hedging and speculative activities. The linkage with the corresponding spot market is considered assuming that a long term equilibrium relationship holds between futures and spot pricing. Over the 1990-2010 time period, a dynamic interaction between spot and futures returns in five commodity markets (copper, cotton, oil, silver, and soybeans) is empirically validated. An error correction relationship for the cash returns and a non linear parameterization of the corresponding futures returns are combined with a bivariate CCC-GARCH representation of the conditional variances.