New Thinking and Old Books Revisited by Krugman
I learn from Francesco Saraceno that some people are attacking me for, as they see it, defending an economic orthodoxy that has failed. It’s kind of an odd place to find myself, given how critical I’ve been of the way the economics profession has dealt with the crisis. But it’s not entirely unfair: I am quite skeptical of people whose response to the sorry state of affairs is to declare that what we need is a whole new field.
Why my skepticism? I’m all for new ideas that add to our understanding. But ideas like that aren’t easy to come by! Mark Thoma’s classic crack — “I’ve learned that new economic thinking means reading old books” — has a serious point to it. We’ve had a couple of centuries of economic thought at this point, and quite a few smart people doing the thinking. It’s possible to come up with truly new concepts and approaches, but it takes a lot more than good intentions and casual observation to get there.
So, for example, what do I say when I read something like this from someone who apparently considers himself a bold rebel against orthodoxy?
“Rational thinking is an important aspect of human nature, but we have imagination, we have ambition, we have irrational fear, we are swayed by other people, we get indoctrinated and we get influenced by advertising,” he says. “Even if we are actually rational, leaving it to the market may produce collectively irrational outcomes. So when a bubble develops it is rational for individuals to keep inflating the bubble, thinking that they can pull out at the last minute and make a lot of money. But collectively speaking . . . ”
My answer, to put it in technical terms, is “Well, duh.” Maybe grad students at some departments, who are several generations into the law of diminishing disciples, really don’t know that rational behavior is at best a useful fiction, that markets aren’t perfect, etc, etc. But does this come as news to Robert Shiller? To Ben Bernanke? To Janet Yellen? To Larry Summers? Would it have come as news to Irving Fisher or Walter Bagehot?
The question is what you do with this insight.
There is definitely a faction within economics that considers it taboo to introduce anything into its analysis that isn’t grounded in rational behavior and market equilibrium. But what I do, and what everyone I’ve just named plus many others does, is a more modest, more eclectic form of analysis. You use maximization and equilibrium where it seems reasonably consistent with reality, because of its clarifying power, but you introduce ad hoc deviations where experience seems to demand them — downward rigidity of wages, balance-sheet constraints, bubbles (which are hard to predict, but you can say a lot about their consequences).
You may say that what we need is reconstruction from the ground up — an economics with no vestige of equilibrium analysis. Well, show me some results. As it happens, the hybrid, eclectic approach I’ve just described has done pretty well in this crisis, so you had better show me some really superior results before it gets thrown out the window.
Oh, and if you think you’ve found a fundamental logical flaw in one of our workhorse economic models, the odds are very strong that you’ve just made a mistake.
Does this mean that nothing should change in the way we teach economics? By no means — it’s quite clear that the teaching of macroeconomics has gone seriously astray. As Saraceno says, the simple models that have proved so useful since 2008 are by and large taught only at the undergrad level — they’re treated as too simple, too ad hoc, whatever, to make it into the grad courses even at places that aren’t very ideological.
Furthermore, to temper your modeling with a sense of realism you need to know something about reality — and not just the statistical properties of U.S. time series since 1947. Economic history — global economic history — should be a core part of the curriculum. Nobody should be making pronouncements on macro without knowing a fair bit about the collapse of the gold standard in the 1930s, what actually happened in the stagflation of the 1970s, the Asian financial crisis of the 90s, and, looking forward, the euro crisis.
I’d put my oar in for history of thought, too. Watching highly trained economists reinvent old economic fallacies suggests to me that there would be real payoff to requiring that students have some idea how the current leading doctrines got to where they are.
But must we reconstruct all of economics? No. Most of what we need, at least for now, is in those old books.