Over at Grist, Lisa Heinzerling, a Georgetown law professor, has written an essay arguing against the embrace of cost-benefit analysis by environmentalists. She suggests that environmentalists enjoy nature in a very concrete and reverential manner that cannot be captured by economic analysis.:

These values are foreign to the cost-benefit mindset. Cost-benefit analysts insist — through use of an arcane technique called discounting — on treating the future as less important than the present. Sometimes, in fact, they effectively dismiss the future altogether. Cost-benefit analysts dismiss the altruist, explaining either that she does not exist or that she cannot know what is best for other people (even if that means saving them from dying). Cost-benefit analysts also speak in nothing but abstractions: Human lives are not human lives, but “statistical lives” — a handy construct that allows economists to pretend that life itself is not at stake in debates over environmental policy. And shivers of joy and glimpses of the infinite do not appear in cost-benefit tables.

Cost-benefit analysis also produces results that are kin to neither reason nor compassion. Scientists around the world now urge us to act quickly to prevent catastrophic effects from climate change. Many economists soberly advise us to do nothing, or very little, because their calculations demonstrate that the future is worth very little, that people prefer warm weather to cold, and that humans in poor countries are not worth as much as humans in rich ones. These calculations are not the work of the radical fringe in economics; they come from highly regarded cost-benefit practitioners. But they are unreasonable and uncompassionate all the same.

I obviously think that this is a fairly substantial misinterpretation of the use of cost-benefit analysis. Heinzerling makes a number of key errors. First, economists aren’t pulling their discount rates out of nowhere, they’re making an effort to capture actual human valuations of the future. Analysts place less value on outcomes well down the road, because you and I do, too. That’s what interest rates are all about.

It’s also important to note that there are disagreements within the economic community about what an appropriate discount rate should be. It’s a bit dishonest to argue that the median economic position is that nothing should be done; certainly some in the field believe this, but in many cases their rate choices are influenced by ideology more so than data. If we remove the cost-benefit abstraction, their positions would not substantially change. The analysis isn’t the evil in such cases, the belief system is.

And at times, Heinzerling seems to acknowledge this, suggesting that cost-benefit analysis might have been all right in her book if only the users had gotten their numbers right–that is, come up with discount rates more favorable to her position. She also acts as if it’s improper to consider these analyses alongside other pieces of information, as if once the dollar abstraction has been made, all other information has been erased. That’s not the case at all, and in fact many economists have looked at different economic models of climate change, observed the findings, and speculated that other things are worth taking into consideration.

But the big–enormous, really–problem with this line of thought is that there is no good alternative. Economists, by and large, haven’t adopted this mindset because they’re emotionless and cruel. They’ve adopted these techniques because it’s almost impossible to grapple with the problems and solutions involved without abstracting to some degree. It’s all well and good to observe that the globe is warming, and the spiritual power of nature compels us to act to halt this process, but then what? What changes should be made, who will those changes help and hurt, and what costs should we be prepared to accept in this battle?

I suppose that she would answer that more should be done, and that present humans should be prepared to suffer more for the sake of the future. Ok, fine. Why? Are costs not to be considered at all? Are all potential trade-offs to be ignored? A person in her position, observing the environmental destruction of the industrial age, might have argued that we were vastly underestimating the costs of such destruction. On the other hand, the wealth generated from that industrialization has materially improved billions of lives.

I think it’s important to acknowledge the weaknesses and limitations in any of the models used to establish costs and benefits, and to fill in gaps with qualitative information when possible. But to toss out the analysis completely is bound to do more harm than good. Doing so would, in all likelihood, lead to worse decision making. It would also deprive environmentalists of a common language with policy makers and skeptics. Answering hard numbers with discussions of nature’s transcendent power is unlikely to be helpful when the rubber meets the road.

If environmentalists don’t want to be marginalized, and if they don’t want the weight of undo human suffering on their hands and consciences, then they’d do well to embrace cost-benefit analysis. Because these issues are so important, we can’t afford to toss aside the best analytical tools we have, imperfect as they may be.