FT's take on Obama's car efficiency plan

Although a tax of $1 or $2 per gallon of petrol would be more effective in altering consumer behaviour and giving a clear demand signal to manufacturers to produce more fuel-efficient vehicles, it would not get through Congress.

But it is an inefficient – and probably ineffective – way of meeting the twin aims Mr Obama has set out for the motor industry and the US carmakers: to curb fuel consumption and dependence on foreign oil and to help the Detroit three “once more outcompete the world”.

The corporate average fuel economy (CAFE) rules that Mr Obama wants to tighten have a history of causing unintended consequences. They were passed in 1975, following the oil crisis, to get drivers to buy smaller and more efficient cars, but instead gave Detroit an incentive to make sports utility vehicles.

The basic problem with the CAFE standards is that, rather than altering patterns of demand, they attempt to ration supply. This flaw is exacerbated by the divide in the rules between standards for “cars” and for “light trucks”, which Detroit has ingeniously exploited.

By the 1980s, petrol was cheap again and drivers did not want to buy the lighter, less powerful cars that were fuel-efficient. Instead, they switched en masse to people carriers and SUVs that were classified as light trucks, and so could be thirstier...

A petrol tax is a rare example of a policy that would be simple, let the market operate, and be likely to achieve Mr Obama’s aims. “This is a noble long-term goal, but a gas tax is an immediate incentive to change,” says David Gerard, an economist at Carnegie Mellon university.

Unfortunately, raising the federal petrol tax, which is currently 18 cents per gallon, to levels that would make it bite is not politically achievable in the US. Instead, the president has had to rally everyone around a clunky and leaky regulatory alternative. That really is extraordinary. [FT]