This article uses the theories of market efficiency and supply of storage to develop a conceptual link between the corn and ethanol markets and explores statistical evidence for the link. We propose that a long-run no-profit condition is established in distant futures markets for ethanol, corn and natural gas and then use the theory of storage to define an inter-temporal equilibrium among these prices. The relationship shows that under certain conditions, future price expectations will influence nearby futures prices and that a short-term relationship between input and output prices will exist. We demonstrate validity of the theory using a structural price model and then by means of time-series techniques.