This post first appeared on Bloomberg.com on August 22, 2013. Thanks to Evan for giving me permission to reprint it here. 

trong consensus on policy still eludes most branches of economics. How can poor countries best achieve rapid sustainable growth, for instance? That’s probably the most important question in all of economics. Development economists have “very little clue,” according to Lane Kenworthy, a leading scholar in the field and professor at the University of Arizona. But there’s an interesting exception. Without attracting much notice, one branch of the discipline has made a lot of progress in devising polices that command consensus: environmental economics.

Of course, recommendations aren’t necessarily followed by policy makers. The U.S. is still far away from taxing on carbon emissions, for instance, as just about every environmental economist would favor. But the field has some practical successes to boast of. At the top of the list is a program that rations the right to fish, known as “catch share.” It has proven shockingly successful in halting overfishing and ecological collapse – the point at which stocks can no longer replenish themselves.

A study of 11,135 fisheries showed that introducing catch share roughly halved the chance of collapse. The system caught on in the 1980s and 1990s after decades of other well-intentioned efforts failed. Economist H. Scott Gordon is usually credited with laying out the problem and the solution in 1954.

Modern environmental economists accuse their predecessors of forgetting about incentives. Catch-share schemes issue permits to individuals and groups to fish some portion of the grounds or keep some fraction of the total catch. If fishermen exceed their share, they can buy extra rights from others, pay a hefty fine or even lose their fishing rights, depending on theparticular arrangement. The system works because it aligns the interests of individual fishermen with the sustainability of the entire fishery. Everybody rises and falls with the fate of the total catch, eliminating destructive rivalries among fishermen.

Environmental economists have lately turned their attention to Atlantic bluefin tuna and whales. The National Marine Fisheries Service has just proposed new regulations that would for the first time establish a catch-share program for the endangered and lucrative bluefin. And a group of economists is pushing for a new international agreement on whaling.

In both cases the problem is overfishing. The bluefin tuna population has dropped by a third in the Atlantic Ocean and by an incredible 96 percent in the Pacific. And whaling, which is supposedly subject to strict international rules that ban commercial fishing and regulate scientific work, is making a sad comeback. The total worldwide annual catch has risen more than fivefold over the last 20 years.

Ben Minteer, Leah Gerber, Christopher Costello and Steven Gaines have called for a new and properly regulated market in whales. Set a sustainable worldwide quota, they say, and allow fishermen, scientists and conservationists alike to bid for catch rights. Then watch the system that saved other fish species set whaling right.

The idea outrages many environmentalists. Putting a price on whales, they argue, moves even further away from conservationist principles than the current ban, however ineffective. They’re wrong. “The arguments that whales should not be hunted, whatever their merits, have not been winning where it counts – that is, as measured by the size of the whale population,” says economist Timothy Taylor, editor of the Journal of Economic Perspectives.

I’d go further. Whale auctions would attract green donations to reduce catches below the quota. Environmental groups might find that the system was a blessing in disguise. If Japan were forced to buy permits to support its “scientific research,” the biggest loophole in the current ban on commercial whaling would be closed. Japan will resist the idea – but if it were persuaded to comply, environmental economics could score one of its greatest triumphs.