Volatility in Wheat Spot and Futures Markets, 1950–1993: Government Farm Programs, Seasonality, and Causality




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    • Crain and Lee are from University of Oklahoma. The authors acknowledge the helpful comments of Louis Ederington, an anonymous referee, and the editor, René Stulz. The Center for Financial Studies at the University of Oklahoma provided financial support for data acquisition. Lee was partially supported by a Noble Research Grant and a Center for Financial Studies Research Grant from the University of Oklahoma.


We explore how wheat spot and futures market volatility has been impacted by government farm programs during the 1950–1993 period. We find that changing volatility in both markets is highly associated with changing farm programs. The mandatory allotment programs of the 1950s and early 1960s (1/3/50–4/10/64) were associated with low volatility, while the voluntary programs initiated in the mid 1960s seem to have induced high volatility (4/11/64–12/22/85). Both market-driven loan rates and conservation reserve programs appear to have helped volatility revert to lower levels since the mid 1980s (12/23/85–12/30/93). We also examine seasonality and causality in conjunction with the farm programs.