Here is perhaps the most incredible part: Because of the subsidy, ethanol became cheaper than gasoline, and so we sent 397 million gallons of ethanol overseas last year. America is simultaneously importing costly foreign oil and subsidizing the export of its equivalent.

That’s not all. Ethanol packs less punch than gasoline and uses considerable energy in its production process. All told, each gallon of gasoline that is displaced costs the Treasury $1.78 in subsidies and lost tax revenue.

Nor does ethanol live up to its environmental promises. The Congressional Budget Office found that reducing carbon dioxide emissions by using ethanol costs at least $750 per ton of carbon dioxide, wildly more than other methods. What is more, making corn ethanol consumes vast quantities of water and increases smog.

Then there’s energy efficiency. Studies reach widely varying conclusions on that issue. While some show a small saving in fossil fuels, others calculate that ethanol consumes more energy than it produces.