THE Bush administration affectionately calls it "cash for clunkers."
As government initiatives go, it is no show-stopper - or economy jump-starter.
But some new federal rules to lure high-polluting old cars off the roads represent a nearly perfect model of how the Bush White House would like government to operate.
The idea is to use market incentives to make it cheaper and easier for polluting businesses to meet clean-air standards.
A business that faces expensive investments to clean up its emissions could instead buy up old cars that put out a similar amount of the same pollutants and scrap them.
The business would be credited with the reduction in pollution, so that it could avoid or perhaps delay more expensive steps.
The appeal of this approach is that, at least in theory, it cleans the air as much as existing regulations, it does it in a cheaper and more efficient way that is less onerous to business, it may often accomplish it sooner, and it costs government no extra money.
The Bush administration has already endorsed using market mechanisms to fight acid rain. Under the 1990 Clean Air Act, utility plants in the same air basin can trade credits for reducing sulfure dioxide emissions.
In smoggy Los Angeles, local officials are making far bolder moves into tapping market efficiencies to cut pollutants affordably.
But the cash-for-clunkers notion takes the market approach into new territory - trading between stationary sources (oil refineries, bakeries) and mobile sources (cars).
"It's critical that we do this," says Joe Goffman, senior attorney at the Environmental Defense Fund, because in cities like Los Angeles, stationary pollution sources have already made the cheap, easy cleanups. Now the ones needed are more difficult.
The program will apply to older cars, which emit the most pollution.
Cars older than 1980 models spew out 86 percent of the volatile organic compounds and 86 percent of the carbon monoxide, yet they represent only 38 percent of the cars on the road, according to the Environmental Protection Agency.
Fully half the hydrocarbons cars emit come from the tailpipes of 6 percent of the cars. The cleanest half of the nation's vehicle fleet emit a mere 3 percent of the hydrocarbons.
New cars produce a bare remnant of the noxious fumes of older models.
From before the first emissions controls were introduced in 1971, to 1983, when emissions standards reached modern levels, the average new car had eliminated 96 percent of the hydrocarbons and carbon monoxide from its exhaust and 67 percent of the nitrogen oxides.
Roughly 4 million cars older than 1971 are still on the road.
The EPA is drafting a formula book calculating how much of which pollutants come from each model and year of car, and how many years of driving life a given car is likely to have.
The formula will also account for the new, or newer, car the old-car driver is likely to buy to replace his clunker. Those emissions are substracted out of the equation.
The program also requires evidence such as continuous licensing and insurance for the car in the local area so that the clean-air goals are not cheated.
Environmentalists remain skeptical that this attractive concept will be carried out faithfully. "It's a program that just begs to be gamed," says Daniel Weiss of the Sierra Club's Washington office. A retired clunker might be local, for instance, but the owner could replace it with an equally dirty one from outside the area.
The EPA will have the guidelines for this program drafted within a month. Local officials will then have the option of carrying it out.