Equilibrium Commodity Trading

Abstract

We develop an equilibrium model of commodity spot and futures markets in which commodity production, consumption, and speculation are endogenously determined. Speculators facilitate hedging by the commodity suppliers. The entry of new speculators thus increases the supply of the commodity and decreases the expected spot prices, to the benefits of the end-users. However, this entry may be detrimental to the producers, as they do not internalize the price reduction due to greater aggregate supply. In the presence of asymmetric information, speculation on the futures market serves as a learning device. The futures price and open interest reveal different pieces of private information regarding the supply and demand side of the spot market, respectively. When the accuracy of private information is low, the entry of new speculators makes both production and spot prices more volatile. The entry of new speculators typically increases the correlation between financial and commodity markets.

Keywords: commodity markets, speculation, asymmetric information

JEL Classification: D5, D51, D61, D82