Thurman, Walter N.

By: Karali, Berna; McNew, Kevin; Thurman, Walter N.
Wheat futures contracts failed to converge to spot prices at delivery locations in 2008–2009. By analyzing basis at nondelivery locations surrounding this episode, we study the spatial pattern of failures to converge. We find that basis fell as distance from delivery location increased and remained tightly connected to basis at the delivery location during the nonconvergence episodes. This finding is uniform throughout the delivery zone. We conclude that nonconvergence did not affect the economic relationship between delivery and nondelivery locations’ spot prices but only affected the connection between futures prices and spot prices.
By: Karali, Berna; Thurman, Walter N.
We analyze the determinants of daily futures price volatility in corn, soybeans, wheat, and oats markets from 1986 to 2007. Combining the information from simultaneously traded contracts, a generalized least squares method is implemented that allows us to clearly distinguish among time-to-delivery effects, seasonality, calendar trend, and volatility persistence. We find strong evidence of time-to-delivery (Samuelson) effects and systematic seasonal components with volatility increasing prior to harvest times— an indirect confirmation of the theory of storage.