William O'Keefe demolishes the lame justifications offered for requiring ethanol in gasoline (Opinion, Sept. 18). But his argument falters when he turns to automobile fuel economy. Citing a National Academy of Sciences study, he implies automakers could build higher-mileage cars without raising prices or reducing seating or cargo capacity. Right. Automakers, in cutthroat competition for market share, are refusing to build cars that potential customers would find more appealing. In reality, even with pricey gasoline and smaller models getting 30-plus miles per gallon, motorists continue to choose larger cars averaging 21 mpg. Automakers could increase fuel economy on larger cars, but only with technologies that would raise purchase costs by more than the fuel savings.

Visiting Fellow Joel Schwartz

If there's a "problem" here, it's that policy makers want to override Americans' preferences under the guise of delivering a free lunch.

Joel Schwartz is a visting fellow at AEI.