Forward Trading and Collusion in Supply Functions

Abstract

This paper studies the effect of forward contracts on the stability of collusion among firms, competing in supply functions on the spot market. A forward market can increase the range of discount factors which allow to sustain collusion. On the contrary, collusion is destabilised when a potential deviator sells a significant amount forward. Results do not depend on the type (financial or physical) of contract fulfilment and are robust to different levels of demand uncertainty. As a policy implication, the study finds that liquid and anonymous forward markets are incompatible with collusion.

Keywords: forward trading; collusion; supply function equilibrium

JEL Classification: C73, D43, L13, G13