Although the United States cannot unilaterally lower the price of oil, it can reduce its consumption, by using oil more efficiently and by developing alternative sources of fuel. For example, the Obama administration has raised the corporate average fuel economy standards imposed on automakers. If consumers buy more fuel-efficient cars and trucks, demand for gasoline falls, as does the burden imposed by high gas prices. But while such rules help, they are not the best way of achieving societal goals.

A better approach would be to gradually raise the gasoline tax to levels similar to those in Western Europe, where fuel-efficient cars are the norm. N. Gregory Mankiw — the Harvard economist who advises Mr. Romney and is a fellow contributor to the Economic View column — has long advocated such a policy. I agree with him, as do most other economists.

For evidence, note that the economists in that same University of Chicago poll were asked whether they agreed with this statement: “A tax on the carbon content of fuels would be a less expensive way to reduce carbon-dioxide emissions than would a collection of policies such as ‘corporate average fuel economy’ requirements for automobiles.”

On this question, there was just a single negative vote.