Cheaper Fuel = More Fuel Consumed

In his latest Boston Globe column, Jeff Jacoby explains "The Paradox of Fuel Efficiency," as the article's title calls it. Jacoby points out that people have been pushing for the production and use of more-fuel-efficient cars for several decades:

If the vehicles on our roads got more miles to the gallon, we have been told again and again, we could dramatically reduce the amount of oil we depend on -- and from that would flow benefits equally dramatic:

America's foreign policy would be strengthened, it is said, since we would no longer have to appease the unsavory regimes that control most of the world's crude oil. The economy would surge as money now spent on fuel was channeled to more productive uses. Mother Earth would be better off, since less fuel would mean less pollution and less drilling for oil. And at a time of $3-a-gallon gasoline, motorists would have particular reason to rejoice: Higher-mileage cars would need fewer expensive fill-ups.

The Bush administration, Jacoby notes, has proposed new regulations to require increased gas mileage in passenger cars, saying "the plan would save 10 billion gallons of gasoline by 2011." But Jacoby points out the the expected fuel savings will not come, and in fact the opposite will happen:

[The Bush proposal and other such measures] might be worth considering if using fuel more efficiently really would result in less fuel being used. But it won't. It will result in more fuel being used.

If that sounds counterintuitive, think about it this way: Would lowering the price of operating an automobile -- i.e., making driving cheaper -- lead to higher or lower consumption? Higher, of course: The cheaper something is, the more of it we generally want. Cars that run more efficiently make transportation cheaper by getting more miles out of each gallon of gas. Result: more miles driven and more gasoline consumed.

Jacoby points out that the creation of more efficient computers has brought not less use of computers but far more use of them. Just so with passenger cars, the evidence shows:

In The Bottomless Well, a myth-busting new book on energy and how we use it, Peter Huber, a scholar at the Manhattan Institute, and Mark Mills, a physicist and technology expert, acknowledge that this paradox -- ''the more efficient our technology, the more energy we consume" -- strikes many people as heretical. But the numbers bear it out. Thirty years ago, the energy cost of transportation was nine gallons per 100 vehicle miles. Today it is six gallons -- a 33 percent drop. Yet over the same period, the total amount of fuel consumed rose 56 percent -- from 115 billion gallons a year to more than 180 billion gallons.

This ''paradox of efficiency" is as true of cars and computers as of light bulbs, jet turbines, and air conditioners, Huber and Mills write. ''The more efficient they grew, the more of them we built, and the more we used them -- and the more energy they consumed overall."

Both Jacoby and I are drivers of fuel-efficient cars, as it happens, and we both support the quest for increased fuel efficiency. But it is important for all of us to know the real reasons for supporting this particular choice, and to recognize what the real social and economic consequences will be. As Jacoby notes, "fuel-efficient cars do have their advantages. Reducing American dependence on oil just doesn't happen to be one of them."