DeLong on the State of Macroeconomics

This is a funny but serious posting by Brad DeLong on the crisis in economic theory: the inability of macroeconomics to account for the periodic crises in the economy, the business cycles gone seriously bad.

If you ask a modern economic historian—like, say, me—if I know why the world is currently in the grips of a financial crisis and a deep downturn, I will say that I do know and I will give you this answer:

This is the latest episode in a long history of similar episodes of bubble—crash—crisis—recession, episodes that date back at least to the canal bubble of the early 1820s, the 1825-6 failure of Pole, Thornton, and company, and the subsequent first industrial recession in Britain. We have seen this process at work in many other historical episodes as well—1870, 1890, 1929, and 2000, for example. For some reason asset prices get way out of whack and rise to unsustainable levels. Sometimes the culprit is lousy internal controls in financial firms that overreward subordinates for taking risk; sometimes it is government guarantees; sometimes it is the selection of the market as a long run of good fortune leaves the financial market dominated by cockeyed unrealistic overoptimists.

Then the crash comes. And when the crash comes the risk tolerance of the market collapses: everybody knows that there are immense unrealized losses in financial assets and nobody is sure that they know where they are. The crash is followed by a flight to safety. The flight to safety is followed by a steep fall in the velocity of money as investors everywhere hoard cash. And the fall in monetary velocity brings on a recession.

I will not say that this is the pattern of all recessions: it isn’t. But I will say that this is the pattern of this recessions—that we have been here before.

If you ask the same question of a modern macroeconomist—like, say, the extremely sharp Narayana Kocherlakota of the University of Minnesota—you will find that he says that he does not know:

Why do we have business cycles? Why do asset prices move around so much?... [M]acroeconomics has little to offer by way of answer to these questions...

He will say that there are models that attribute economic downturns to various causes:

[M]ost models in macroeconomics rely on some form of large quarterly movements in the technological frontier. Some have collective shocks to the marginal utility of leisure. Other models have large quarterly shocks to the depreciation rate in the capital stock (in order to generate high asset price volatilities)...

That is, downturns are either the result of a great forgetting of technological and organizational knowledge, a great vacation as workers develop a sudden extra taste for leisure, or a great rusting as the speed with which oxygen in the air corrodes speeds up and so reduces the value of large things made out of metal.

...

This situation is personally and professionally dismaying. I do not say that the macroeconomic model-building of the past generation has been pointless. I don’t think that it has been pointless. But I do think that the assembled modern macroeconomists need to be rounded up, on pain of loss of tenure, and sent to a year-long boot camp with the assembled monetary historians of the world as their drill sergeants. They need to listen to and learn from Dick Sylla about Alexander Hamilton’s bank rescue of 1825 and Charlie Calomiris about the Overend, Gurney crisis and Michael Bordo about the first bankruptcy of Baring brothers and Barry Eichengreen and Christy Romer and Ben Bernanke about the Great Depression.

If modern macreconomics does not reconnect—if they do not realize just what their theories are crystallized out of, and what the point of the enterprise is—then they will indeed wither and die.

I want to see Brad decked out with the fancy uniform with all the gold braid shouting until he is red in the face trying to shape up all those macroeconomists. I would pay good money for a ring side seat!