It’s good to see that Paul Krugman is channeling Marty Weitzman on the urgency of preventing catastrophic climate change. Here is what the Weitzman analysis means for economists.
Weitzman argues forcefully that in the face of extreme risk and great uncertainty, the quest for “optimal” policies is futile. The point is simply to insure against the worst, and that will mean very aggressive programs to stabilize greenhouse gases at a tolerable level. (Bill McKibben wants us to memorize 350 ppm.) It turns out that stopping runaway climate change is at heart an ecological problem, not an economic one.
Meanwhile, a whole industry of economists, financed by clueless foundations, are barking up the wrong tree. They assemble and run dubious CGE models estimating marginal costs and benefits, as if anyone in a position to make decisions really cared. In fact, not only is there no reason to believe this line of research has anything to offer, there is no evidence that the advice of economists, even heavy hitters like Nordhaus, have or will have any effect on the main policy parameters, like carbon targets and timetables.
So what should we do with all the economists freed from the quest for the true dollar value of a ton of carbon? Put them to work anticipating the impact of an impending carbon cap and coming up with measures to adapt as painlessly as possible. What regions and industries will be most affected? What policies can smooth their transitions? How much of the capital stock will be written off before amortization and with what affect on employment and the financial system? What are the most cost-effective ways to increase the elasticity of demand for carbon-intensive goods? That is, how can we foster substitutes, fast?
Why are hundreds of economists laboring night and day to answer questions no one with any sense asks any more, while the critical issues of economic adaptation are almost completely ignored? Why are we about to walk blindly into a carbon-constrained world?