Corn for Food, Not Fuel by Colin A. Carter and Henry I. Miller.
Any defense of the ethanol policy rests on fallacies, primarily these: that ethanol produced from corn makes the United States less dependent on fossil fuels; that ethanol lowers the price of gasoline; that an increase in the percentage of ethanol blended into gasoline increases the overall supply of gasoline; and that ethanol is environmentally friendly and lowers global carbon dioxide emissions.
The ethanol lobby promotes these claims, and many politicians seem intoxicated by them. Corn is indeed a renewable resource, but it has a far lower yield relative to the energy used to produce it than either biodiesel (such as soybean oil) or ethanol from other plants. Ethanol yields about 30 percent less energy per gallon than gasoline, so mileage drops off significantly. Finally, adding ethanol actually raises the price of blended fuel because it is more expensive to transport and handle than gasoline.
More at the NYT.