IS economics an enemy of ecology? Many environmentalists seem to think so. They portray economists as insensitive number crunchers with Republican leanings, people stricken by a ghoulish preference for money over ecological integrity. The perceived focus of economics - money, business and mathematics - is distasteful to people motivated by environmental concerns.

But greens' conventional wisdom is wrong. Economic analysis can be environmentalism's best tool. By considering how economics can further environmental objectives, we may be able to alleviate greens' allergy to economics.

Since most resources are scarce, we lose opportunities if we fail to minimize waste. Tumbleweeds in Arizona, spotted knapweed in Montana and bureaucrats in the Department of Agriculture are so overabundant that they are "bads" - not goods. Items we value should be treated as though they are scarce.

When environmental policies waste talent, time or material, the price of environmental protection is higher than necessary. The economist's "first law of demand," a social analog to the law of gravity, states that as the price of a good rises, demand falls. Making environmental quality needlessly expensive subverts environmental goals because the expense lowers people's demand for environmental protection. Americans' growing opposition to needlessly expensive Superfund sites is just one example.

To make the most of limited environmental dollars and to achieve real improvements in pollution control, watershed protection and other important goals, we should first address those problems where the payoffs are greatest per dollar invested. This requires risk-benefit analysis, a method of comparing values (lives, endangered species) that can be saved by investing resources on different problems. Not all activities generate equal benefits. Since we can't do everything, risk-benefit analysis helps us choose among our options.

Greens have shown a curious reluctance to accept risk analysis. Some groups have included it in the "unholy trinity" of principles they oppose in environmental legislation.

But, in terms of achieving green values, environmentalists are misguided when they reject risk analysis. Eliminating some very expensive regulations would save lives or improve health if we thereby free up resources enabling people to achieve less-onerous environmental objectives. Eliminating extremely costly regulations also increases incomes, saving roughly one life for every $7.5 million added to our economy. Richer really is safer and cleaner.

Risk analysis is one way to get more for our environmental efforts. Another is minimizing government micromanagement. When government agencies try to specify how people are to reach environmental objectives, waste and ineffective policies are the predictable result.

Consider the case of the Amoco Corporation's Yorktown, Va., oil refinery. Amoco and the EPA conducted a two-year joint study into how chemical emissions from the Yorktown plant were addressed by existing regulations. They found that EPA regulations required pollution controls that ignored major sources of pollution and were roughly $30 million more expensive than the more-effective approaches uncovered by the study. Amoco's costs were nearly four times greater than needed to achieve regulatory goals, $41 million versus $11 million. Nevertheless, existing regulations disallow the more-efficient strategies.

The Yorktown case illustrates problems endemic to national environmental regulations. Sweeping, undifferentiated regulations are necessarily inflexible, excessively costly, and do little to control pollution. They make few allowances for local situations. Like the Forest Service, BLM and other large centralized bureaucracies, the EPA's regulations are at odds with the ecology of particular places.

Thoughtful risk analysis and the end of regulatory micromanagement can yield better and less-expensive environmental protection.

Some environmental organizations, such as Defenders of Wildlife and the Environmental Defense Fund, are pursuing principled, innovative and constructive policies. However, the leaders of other organizations, including Greenpeace and the Natural Resources Defense Council, see a niche in crisis entrepreneurship. They use shoddy science and biased media coverage to exaggerate (as with chlorine) or fabricate (as with Alar) environmental dangers. These efforts pressure government officials to adopt wasteful policies.

By exaggerating environmental dangers, and posturing as the great green hope with full-page ads in The New York Times, crisis entrepreneurs seduce members and donations. Their budgets, professional status and political influence may increase in the short run. But environmental protection is lost and ethical standards are eroded. Ultimately, the credibility of the environmental movement is reduced.

Economics does not offer a cure-all. Environmental quality implies real changes and real costs. But economics helps us better use our scarce efforts to craft effective policies. It exposes those seeking to use the public's interest in environmental protection for private ends. This is why some fear the use of environmental economics.