How do you know when your research has changed things? And when do you say: “I’ve made enough change — I’ve hit my goal”?
When you’ve changed your field? Or is your ambition a bit larger?
It’s rare, says Tim Harford, to read an economics paper that makes one think: “this changes everything.” But he writes in the Financial Times that he read one over a decade ago: the late environmental economist Martin Weitzman’s review of the Stern Review on the Economics of Climate Change.
In that review, Weitzman argued that the “fat tail” (the small but real set of possibilities) of runaway catastrophic climate change “should rightly loom large in rational calculations,” as Harford puts it. “The extreme scenarios matter. What we don’t know about climate change is more important, and more dangerous, than what we do.”
That’s a big idea. Others had had it before him, but Weitzman (who had a gift for framing) was able to frame it properly — which is to say, in a way that made others sit up and take notice. Weitzman’s frame: we need to act against climate change not, as Lord Stern had argued, out of some cost-benefit calculation to benefit the future (because nobody pays now to benefit future generations they’ll never meet); we need to act as insurance against the risk of existential catastrophe.
The idea of insurance against existential catastrophe for our species and planet got through; it moralized action against climate change in a way nothing else had — certainly not the science itself, not even Al Gore. Weitzman’s idea made the Paris Accords possible. It made papers on front-loading carbon taxes at the highest levels possible…possible. You might even argue it made Greta Thunberg possible.
No surprise, really; because Weitzman believed in working exclusively on big ideas. Some of his other ones: the rationale for profit sharing with employees; biodiversity conservation tradeoffs; taxes versus permitting to reduce pollution. “If you don’t think an idea might be worthy of the Nobel Prize, you shouldn’t be working on it,” Harford quotes him telling one colleague. (A potentially punishing standard. Weitzman killed himself in August, reportedly despondent that he hadn’t won a Nobel Prize, and concerned that, at age 77, he was slipping in acuity, and no longer able to contribute to driving economics forward.)
By 2007, Weitzman’s “insurance-based case for significant worry about climate change” was already “the most current economists’ word,” according to a Tyler Cowen blog post from 2007. 2007.
But Weitzman didn’t stop there. He clearly understood he was in the ideas business, which also meant that when you had ideas, you had to promote them. After 2007, Weitzman wrote a book about the worrisome fat tails with Gernot Wagner, “Climate Shock.” He gave innumerable talks. He and Wagner co-wrote an influential New York Times op-ed on the case for making our uncertainty about climate change a key factor in our decision-making about mitigation and adaptation. He did lots of media interviews. He was a spokesperson for his own ideas. He understood the modern attention economy.
Tim Harford, whose writing I adore, had his mind changed by Martin Weitzman’s paper. Indeed, a paper can still (once in a while) change everything — for your colleagues. But it’s the ideas out of your papers and expertise, and the long campaigns you build to promote them, and the networks you activate and create during those campaigns, that change everything for the rest of us.