We propose and test a theory of using commodities as collateral for financing. Under capital control and collateral constraint, investors import commodities and pledge them as collateral to earn higher expected returns. Higher collateral demands increase commodity prices and make the inventory–convenience yield relation less negative. Our model illustrates these equilibrium effects and suggests that the violation of covered interest-rate parity is a proxy for collateral demands. Evidence from eight commodities in China and developed markets supports the theoretical predictions. Our findings complement the theory of storage and provide new insights into the financialization of commodity markets.

This paper shows that economic linkages among commodities create a source of long-term correlation between futures returns. We extend the theory of storage to a multi-commodity level and find that the convenience yield of a commodity depends on its relative scarcity with respect to other related commodities. This implies a feedback effect between commodities that is necessary to replicate the upward-sloping correlation term structure of futures returns observed for related commodities. We present a multi-commodity affine model that validates our theoretical predictions and considerably reduces the pricing errors in out-of-sample crack spread options.