A New Yorker profile of Paul Krugman focuses on the evolution of his politics.  There are a few passages that describe Professor Krugman's evolution from history major to trade theorist.  First, economics is about capturing the essential elements of a problem in as parsimonious a way as possible without being tautological or trivial.
Economics, he found, examined the same infinitely complicated social reality that history did but, instead of elucidating its complexity, looked for patterns and rules that made the complexity seem simple. Why did some societies have serfs or slaves and others not? You could talk about culture and national character and climate and changing mores and heroes and revolts and the history of agriculture and the Romans and the Christians and the Middle Ages and all the rest of it; or, like Krugman’s economics teacher Evsey Domar, you could argue that if peasants are barely surviving there’s no point in enslaving them, because they have nothing to give you, but if good new land becomes available it makes sense to enslave them, because you can skim off the difference between their output and what it takes to keep them alive. Suddenly, a simple story made sense of a huge and baffling swath of reality, and Krugman found that enormously satisfying.
The evolution of voluntary exchange and emergent cooperation involves a more subtle version of the same phenomenon, leaving for future research whether skimming output is accomplished by force or by exchange. But it's about the essential elements.
Translating unmappable facts into economic discourse, it turned out, was what Krugman was better at than anyone else: he could take an intriguing notion that had come up in real-world discussions, pare away the details (knowing just what to take out and what was essential), and refine what was left into a clean, clever, “cute” (as he liked to put it), and simple model. “It’s poetry,” Kenneth Rogoff, an economist at Harvard, says. “I mean, you go back to his first book and there was this beautiful chart about what the Volcker contraction did to output that swept aside so much—he just drew this little graph which really cleared the air. I’ve heard economists use the word ‘poet’ in describing him for decades.”

Krugman’s theories of trade and economic geography are still taught everywhere. “I think there’s a pretty good case to be made that the stuff that I stressed in the models is a less important story than the things that I left out because I couldn’t model them, like spillovers of information and social networks,” he says. But failure to represent reality accurately is rarely a fatal flaw in an economics model—what’s valued is the model’s usefulness as an analytic tool.
The capturing of essential elements proceeds in steps. Look at the graphs and figures in The American Economic Review in the 1940s and compare what's been added in the past seventy years. The introduction of information spillovers and social networks is keeping the current crop of economists busy.  The task for the senior faculty is to protect the thinking time of the younger economists in order that the progress continues.
But it’s been a long time—years now—since he did any serious research. Could he, still? “I’d like to get back to it,” he says. “I’m craving the chance to do some deep thinking, and I haven’t been doing a lot of that. I guess doing the really creative academic work does require a state of mind that’s hard to maintain throughout your whole life. Even Paul Samuelson—the bulk of the stuff you read from him is before he was fifty. There was an intensity of focus that I had when I was twenty-six that I won’t be able to recapture at fifty-six. You develop your habits of mind, and to a point that’s a good thing, because you learn ways to work, but it does mean that you’re less likely to come up with something really innovative. Even if I weren’t doing all this other stuff, I don’t think I’d be producing a lot of breakthrough papers. There’s crude stuff: if I do have some brilliant academic insight, what are they going to do, give me a Nobel Prize? . . . When I was younger, when I figured something out there was this sense of the heavens parting and the choirs singing that I don’t get now. And that’s life.”

For someone else, this loss might be a devastation, but even though for thirty years thinking deeply about economics was all Krugman really cared about, he has let it pass out of his life without regret. “I think he’s happy,” his friend Craig Murphy says. “A much happier person now than when we first met him. He feels like he’s done good things, and they’re greater than what he expected when he was young. If there is sadness in him at all, I think it is a tiny core of profound sadness of the kind that the Buddha understood—that we probably can’t use human rationality to make the world all better, and it would be really nice if we were able to.”
That's also a point the freshwater economists get, often phrased (with thanks to Professor McCloskey), "If you're so smart, why aren't you rich?"

No comments: