The trend is unmistakable: Clean cars are coming, as this week's cover story makes clear. But they're coming because the states, with California in the vanguard, and the federal government are mandating them. The intent is good--who can argue with the goal of cleaner air? The problem is that without the checks and balances provided by the market, there's no guarantee a legislated solution is the optimum one. Even well-conceived laws produce unforeseen consequences. Sometimes, they can move us farther from our goal.

This may well be true of the push to develop cars that run on some hydrocarbon fuel other than gasoline, or on electricity, or even hydrogen. Retooling to produce one or more of these alternatives will require huge outlays by an industry whose major players are struggling with some of the biggest losses ever recorded by any U. S. business. Will the industry expend these sums only to find that our politicians have bet Detroit's money on the wrong horseless carriage? Will electric cars still seem the way to go if the demand they create for electricity forces utilities to put up new coal-fired or nuclear power plants? How worthwhile will natural-gas cars seem if they turn out to exacerbate global warming? Indeed, what if CO subscript 2, one of the main causes of global warming, proves to be an even greater threat to life on this planet than are the smog-producing pollutants that alternative cars are designed to minimize? It may not require scrapping a decade's worth of work, but it will surely mean billions of dollars of additional expense.

Solving this conundrum isn't easy. Clearly, the auto companies should be encouraged to explore alternative fuels. But any program that does so must remain flexible enough to permit quick lane changes if it becomes clear that improving fuel efficiency is even more critical than building cleaner cars. The present program, a briar patch of state and federal laws, scarcely addresses the CO problem at all. As lawmakers debate new rules that would dramatically tighten fuel-economy standards, they need to ask themselves whether carmakers have the resources to attend to both concerns at once. The system must have enough leeway to let carmakers cope with the most pressing issue.

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