A lot, it turns out. The plan would squander money the nation doesn't have without addressing the fundamental problems.

As energy policy, this program is woefully lacking, as it would apply to trade-ins that improve mileage by only 4 mpg for
cars and 2 mpg for most trucks and SUVs. If the goal is to promote fuel efficiency, higher energy prices are a far more
effective means.

As stimulus, cash-for-clunkers means lemons for taxpayers. It would borrow billions of dollars to benefit a single industry
and a particular class of consumers who decided years ago to buy fuel-inefficient vehicles.

More broadly, this program is part of an unfortunate trend of worthy public policy goals being warped to the benefit of
special interests. Billions of dollars flow to dreadfully inefficient ethanol because a powerful corn lobby shrewdly wraps
itself in the mantle of renewable fuels and energy independence. Billions more go toward expensive weapons that the
Pentagon rates as low priorities because they are built in the states and districts of powerful lawmakers who portray
themselves as patriots.

While admittedly small in comparison, the $4 billion cash-for-clunkers program fits in this category.
The twin goals fuel economy and assistance for the ailing Big Three automakers clash because

Detroit's product lines are skewed toward larger vehicles. One look at the "compromise" worked out between the
White House and House of Representatives makes clear which of these two goals would take precedence.

An owner of an old SUV that gets 18 mpg would get $3,500 toward a new SUV that gets a whopping 20 mpg.
Meanwhile, an environmentally conscious driver with an old car that gets better than 18 mpg could buy one of the
most fuel-efficient cars on the market, the 46 mpg Toyota Prius, and wouldn't get a dime.

It's not hard to see why the plan is structured the way it is. Of the 10 most fuel-efficient cars in America for city driving,
only the Ford Escape hybrid (and equivalents) is made by one of the Big Three.

The program is not the worst economic stimulus idea to come out of Washington. But it doesn't have the same
long-term impact as building roads and transit systems, which has wider benefits while providing jobs immediately.

Cash-for-clunkers would do nothing to address the automakers' basic cost and overcapacity problems, except slightly
delay the day of reckoning. The idea most closely resembles those end-of-month dealer blowouts designed to boost
short-term sales at the expense of future ones. With large numbers of people driving new cars, they would be out of the
market for some time. For these and other reasons, the best we can hope for this plan is that it, too, is junked.

How it would work

Under the "cash for clunkers" plan, the government would send vouchers of $3,500 to $4,500 to dealers on your behalf if you:

Trade in a car that has been registered and in use for at least a year and has a federal combined city/highway fuel economy
of 18 or fewer miles per USgallon.

Buy a new car, $45,000 or less, that gets at least 22 mpg. A car that gets at least 4 mpg better than the trade-in qualifies
for $3,500; at least 10 mpg better qualifies for $4,500.