Are economists too fond of their mathematical models? (Photo: Collections École Polytechnique / Jérémy Barande via Wikimedia Commons)

The economist Dani Rodrik, a professor at Harvard, recently spent a couple of years at Princeton’s Institute for Advanced Study. In his new book, “Economics Rules: Why Economics Works, When it Fails, and How to Tell the Difference,” he recalls just what a “mind-stretching experience” that sojourn was. He found that many of the visitors to the Institute’s School of Social Sciences, prominent academics from other disciplines, harboured a deep “suspicion toward economists.” Those visitors seemed to believe, he writes, that “economists either stated the obvious or greatly overreached by applying simple frameworks to complex social phenomena.” It felt, Rodrik says, as if economists were being cast as the “idiots savants of social science: good with math and statistics, but not much use otherwise.”

Part of the problem, Rodrik thinks, is “misinformation” about what it is economists do, exactly. “Economics Rules” is in part, therefore, an attempt to set the record straight—and to rebut some fairly widespread criticisms of economics in the process. But it’s also aimed at his colleagues in the economics profession, who he thinks have made a sorry fist of “presenting their science to the world.” When I spoke to him on the phone from the United States this week, I asked about that assumption he’d encountered at Princeton—that economists are “good with math and statistics” and not much else.

DR: Often we take it [mathematics] too far. There’s a certain fetishism that comes along with the use of math. And that shows up in two ways: one is that arguments which are relatively straightforward, that can be put in a directly literary form, we feel we have mathematise them. Sometimes, there’s undue mathematisation or formalisation. We get so enamoured of the math that the mathematical structure of models becomes an object of analysis. And that’s one of the problems with economic theory—that it often becomes applied mathematics, where the point is the mathematical properties of the models. And so it becomes more and more peripheral to what economics should be about, which is to look at social phenomena. But there’s a much better appreciation today of the role and also the limits of math in economics than there was 30 years ago.

JD: Right. You say in the book that…

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