You know the story: Xi and his San tribe are “living well off the land.” They are happy because of their belief that the gods have provided plenty of everything, and no one among them has any wants. One day, a Coca-Cola bottle is thrown out of an airplane and falls to Earth unbroken. But the bottle eventually causes unhappiness within the tribe, leading the elders to believe it’s an “evil thing” which the gods were “absent-minded” to send them. Xi then travels to the edge of the world and throws the bottle off the cliff. He then returns to his tribe and receives a warm welcome from his family.
I wonder if Paul Krugman expects to receive a warm welcome from the economics family after throwing the prediction bottle over the cliff.
Hardly anyone predicted the 2008 crisis, but that in itself is arguably excusable in a complicated world. More damning was the widespread conviction among economists that such a crisis couldn’t happen. Underlying this complacency was the dominance of an idealized vision of capitalism, in which individuals are always rational and markets always function perfectly.
I actually agree with Krugman on this point. Economic prediction is, in fact, impossible and the really crazy feature of mainstream economic models is the fact that endogenous crises simply can’t occur. Exogenous factors, sure, but nothing internal to the models can lead to a crash. Their idealized vision of capitalism, absent an external event (such as a credit crunch or an increase in the price of oil), simply leads to a full-employment, price-stable equilibrium.
But, wait, doesn’t the entire edifice fall when—on its own terms—the ability to correct predict is dispensed with? The whole rationale of giving up realistic assumptions about the economic system has been the ability to accurately and correctly predict the movements of the economy. That’s the mantle of predictive science that has been used, since at least the mid-1950s, to expunge all other economic theories and approaches from the discipline.
Mainstream economists can’t have it both ways: to celebrate their models for their predictive ability and then to dispense with prediction when, as in 2007-08 (just as in 1929), their models clearly failed. We need something better.
As for their track record since the crisis broke out, well, they haven’t fared much better—at least to judge by where we stand right now. Krugman, for his part, wants to stick with the hydraulic mechanisms of the textbook economic models, which “did a pretty good job of predicting how things would play out in the aftermath,” and declare that “too many influential” economists must be crazy.