Investment Shocks and the Commodity Basis Spread

I identify a "slope"' factor in the cross section of commodity futures returns. Low-basis commodity futures have higher loadings on this factor than high-basis commodity futures. This slope factor and a level factor -- an index of commodity futures -- jointly explain most of the average excess returns of commodity futures portfolios sorted by basis. More importantly, I find that this factor is significantly correlated with investment shocks, which represent the technological progress in producing new capital. I investigate a competitive dynamic equilibrium model of commodity production to endogenize this correlation. The model reproduces the cross-sectional futures returns.