Where Does Macroeconomics Go From Here?: SEPTEMBER 03, 2009: Paul Krugman has questions:
How Did Economists Get it So Wrong?: Between 1985 and 2007 a false peace settled over the field of macroeconomics. There hadn’t been any real convergence of views between the saltwater and freshwater factions. But these were the years of the Great Moderation — an extended period during which inflation was subdued and recessions were relatively mild. Saltwater economists believed that the Federal Reserve had everything under control. Fresh water economists didn’t think the Fed’s actions were actually beneficial, but they were willing to let matters lie.
But the crisis ended the phony peace. Suddenly the narrow, technocratic policies both sides were willing to accept were no longer sufficient — and the need for a broader policy response brought the old conflicts out into the open, fiercer than ever. Why weren’t those narrow, technocratic policies sufficient? The answer, in a word, is zero.
During a normal recession, the Fed responds by buying Treasury bills — short-term government debt — from banks. This drives interest rates on government debt down; investors seeking a higher rate of return move into other assets, driving other interest rates down as well; and normally these lower interest rates eventually lead to an economic bounceback. The Fed dealt with the recession that began in 1990 by driving short-term interest rates from 9 percent down to 3 percent. It dealt with the recession that began in 2001 by driving rates from 6.5 percent to 1 percent. And it tried to deal with the current recession by driving rates down from 5.25 percent to zero. But zero, it turned out, isn’t low enough to end this recession. And the Fed can’t push rates below zero, since at near-zero rates investors simply hoard cash rather than lending it out. So by late 2008, with interest rates basically at what macroeconomists call the “zero lower bound” even as the recession continued to deepen, conventional monetary policy had lost all traction....
This is the second time America has been up against the zero lower bound, the previous occasion being the Great Depression. And it was precisely the observation that there’s a lower bound to interest rates that led Keynes to advocate higher government spending: when monetary policy is ineffective and the private sector can’t be persuaded to spend more, the public sector must take its place in supporting the economy. Fiscal stimulus is the Keynesian answer to the kind of depression-type economic situation we’re currently in.
Such Keynesian thinking underlies the Obama administration’s economic policies — and the freshwater economists are furious. For 25 or so years they tolerated the Fed’s efforts to manage the economy, but a full-blown Keynesian resurgence was something entirely different. Back in 1980, Lucas, of the University of Chicago, wrote that Keynesian economics was so ludicrous that “at research seminars, people don’t take Keynesian theorizing seriously anymore; the audience starts to whisper and giggle to one another.” Admitting that Keynes was largely right, after all, would be too humiliating a comedown. And so Chicago’s Cochrane, outraged at the idea that government spending could mitigate the latest recession, declared: “It’s not part of what anybody has taught graduate students since the 1960s. They [Keynesian ideas] are fairy tales that have been proved false. It is very comforting in times of stress to go back to the fairy tales we heard as children, but it doesn’t make them less false.” (It’s a mark of how deep the division between saltwater and freshwater runs that Cochrane doesn’t believe that “anybody” teaches ideas that are, in fact, taught in places like Princeton, M.I.T. and Harvard.)
Meanwhile, saltwater economists... were shocked to realize that freshwater economists hadn’t been listening.... Freshwater economists [like Lucas, Prescott, Fama, Cochrane, Mulligan, Zingales, Boldrin, etc.] who inveighed against the stimulus didn’t sound like scholars who had weighed Keynesian arguments and found them wanting. Rather, they sounded like people who... were resurrecting pre-1930 fallacies in the belief that they were saying something new and profound. And it wasn’t just Keynes whose ideas seemed to have been forgotten. As Brad DeLong of the University of California, Berkeley, has pointed out in his laments about the Chicago school’s “intellectual collapse,” the school’s current stance amounts to a wholesale rejection of Milton Friedman’s ideas as well. Friedman believed that Fed policy rather than changes in government spending should be used to stabilize the economy, but he never asserted that an increase in government spending cannot, under any circumstances, increase employment. In fact, rereading Friedman’s 1970 summary of his ideas, “A Theoretical Framework for Monetary Analysis,” what’s striking is how Keynesian it seems.
And Friedman certainly never bought into the idea that mass unemployment represents a voluntary reduction in work effort or the idea that recessions are actually good for the economy. Yet the current generation of freshwater economists has been making both arguments.... Chicago’s Casey Mulligan.... Cochrane declares that high unemployment is actually good: “We should have a recession. People who spend their lives pounding nails in Nevada need something else to do.” Personally, I think this is crazy. Why should it take mass unemployment across the whole nation to get carpenters to move out of Nevada? Can anyone seriously claim that we’ve lost 6.7 million jobs because fewer Americans want to work? But it was inevitable that freshwater economists would find themselves trapped in this cul-de-sac: if you start from the assumption that people are perfectly rational and markets are perfectly efficient, you have to conclude that unemployment is voluntary and recessions are desirable.
Yet if the crisis has pushed freshwater economists into absurdity, it has also created a lot of soul-searching among saltwater economists. Their framework, unlike that of the Chicago School, both allows for the possibility of involuntary unemployment and considers it a bad thing. But the New Keynesian models that have come to dominate teaching and research assume that people are perfectly rational and financial markets are perfectly efficient. To get anything like the current slump into their models, New Keynesians are forced to introduce some kind of fudge factor that for reasons unspecified temporarily depresses private spending. (I’ve done exactly that in some of my own work.) And if the analysis of where we are now rests on this fudge factor, how much confidence can we have in the models’ predictions about where we are going?
The state of macro, in short, is not good. So where does the profession go from here?...
I remember October of 1987. We--that is me, Andrei Shleifer, Larry Summers, and Robert Waldmann--had what we regarded as a very nice paper about the instability of irrational agents' beliefs as itself a powerful barrier to arbitrage. We then watched the stock market crash by 25% in one day. And we thought that we had won the argument: that the efficient market hypothesis couldn't come back from a 25% market collapse on a day when absolutely nothing fundamental happened.
But then we were told that something fundamental had happened: there had been a sudden shock to the required expected rate of return on equities and the market had reacted efficiently to that shock. However, when I tried to process this, I could not understand it other than as an assertion that the market had gone down for no reason and would eventually recover--but that this was not a problem because it was consistent with the efficient market hypothesis...