Let Them Eat Switchgrass? Modeling the Displacement of Existing Food Crops by New Bioenergy Feedstocks∗

We propose an econometric model of crop choice in which a farmer’s profit-maximizing crop depends on physiological crop attributes interacted with local soil and climate characteristics. We estimate the model using county-level data on average crop choices for 1986–2008. We find that attributes of chosen crops correlate as expected with geographic variation in soil and climate characteristics. For example, crops that use water efficiently tend to be grown in dry regions, while crops with long growing seasons tend to be grown in warmer climates. The model allows us to forecast, based on revealed historical crop choices, the adoption of two leading bioenergy crops, switchgrass and miscanthus, that do not yet exist in the historical data but whose attributes are known. At the scale of production mandated by the federal Renewable Fuel Standard, we find that both switchgrass and miscanthus would displace a wide range of major food crops. Driven by their relative tolerance for cold, these new crops would tend to concentrate in the northern plains, with disproportionately large impacts on alfalfa, barley, sunflowers, and wheat and somewhat milder impacts on corn, cotton, sorghum, and soybeans. These results could be used to validate the findings of simulation models or to help parameterize a model of U.S. crop supply, while our overall approach could easily be extended to include additional crops and