Thursday, December 20, 2012

The Confused and the Confusing

I don't know why, but I find Paul Krugman's behavior interesting. Here's his reply to my previous post. This is typically the way he does it. For some reason Noah Smith is always the conduit.

The first thing to note is this:
For newbies: saltwater is the kind of macro practiced at MIT, some of Harvard, Princeton, etc., macro that still finds Keynesian ideas useful and argues that monetary and fiscal policy can be effective; freshwater is Chicago, Minnesota, etc. insisting that business cycles are optimal responses to real shocks.
This is not actually a message for newbies. Krugman seems to be hoping that these "newbies" are Rip Van Winkles who have been asleep for 30 years rather than 20. Or maybe he thinks that repeating this enough will make it true. From my previous post:
What are "freshwater" and "saltwater" macro? No idea. In Paul Krugman's own department at Princeton, Richard Rogerson, who was a student of Ed Prescott's, resides with Nobu Kiyotaki, who was a student (or at least a coauthor) of Olivier Blanchard's. There are other macroeconomists there with PhDs from Chicago, Minnesota, and MIT. What school of thought drives that place? Beats me.
If Krugman can't figure out what is going on in his own department, do you think you can trust him to take the pulse of the profession?

A second thing:
So yes, the equations in one of Mike Woodford’s papers look a lot like the equations coming out of Chicago or Minneapolis. And a few years ago it was possible to delude oneself into believing that this represented a true convergence of thought.
There's much more to it than equations. Here's an example. In fall 2008, I went to this conference at the Federal Reserve Bank of Minneapolis. What was it about? Monetary Policy and Financial Frictions. That's in the middle of the crisis, and it was certainly topical. I didn't see anyone there obsessing about TFP shocks. People came from across the country - Princeton, Chicago, MIT, Northwestern, Stanford, Columbia, etc.

One paper I saw was Mike Woodford's work with Curdia. Woodford/Curdia start with a basic NK framework and add a financial friction, in part by introducing some heterogeneity to generate borrowing and lending. When I first saw the program, I was wondering why Andy Atkeson was discussing the paper. I wouldn't have thought that Andy knows much about NK models. Wrong. Actually, what Mike was doing uses some ideas from the market segmentation literature that Andy has done work in. There was basically a set of shared ideas, techniques, and tricks for getting the job done. Cross-fertilization! Market segmentation is about studying the distributional effects of monetary policy - a nonneutrality of money. Mike works in models where the nonneutrality generally comes from price stickiness. Andy was a Sargent student at Stanford. His first job was at Chicago, and he is now at UCLA. Mike at one time also worked at Chicago, and he was at Princeton, then Columbia.

Here's something I could have said:
I’m not saying that the NK approach is necessarily right; but it’s a serious intellectual effort, undertaken by people who thought they were part of an open professional dialogue.
So Krugman and I have something we can agree on.

Krugman seems to want us to be at each others' throats. Only he can tell us why.

Monday, December 17, 2012

Rottenness

I thought I would offer some light entertainment today. This Paul Krugman post struck me as perhaps more deranged than usuual on the topic of macroeconomists.

Here are the two closing paragraphs, to give you the idea:
In fact, the freshwater side wasn’t listening at all, as evidenced by the way 80-year-old fallacies cropped up as soon as an actual policy response to crisis was on the table; and as for changing views in response to facts, well, we all know how that has gone.

The state of macro is, in fact, rotten, and will remain so until the cult that has taken over half the field is somehow dislodged.
Like most of the macroeconomists I know and talk to, I try to keep up with my field, and with what is going on in the rest of economics. That's a hard thing to do of course. It burns all the time that is left after teaching students, trying to do one's own research, and doing whatever else we need to do to get on with life.

It doesn't surprise me that Paul Krugman isn't up on what is going on in macroeconomic research. Why should we expect him to go to macro conferences, spend time in seminars, and talk to his colleagues at Princeton? He has plenty on his plate, what with delivering two NYT columns per week, blogging, talking to pundits, and giving speeches. But if he's not up on the field, what purpose does it serve to make up outlandish stuff for people to read? Maybe this just motivates the Krugman base. I have no idea.

Some of the following ideas you can find in other forms if you search my archive, but these things bear repeating once in a while.

This is actually a relatively tranquil time in the field of macroeconomics. Most of us now speak the same language, and communication is good. I don't see the kind of animosity in the profession that existed, for example, between James Tobin and Milton Friedman in the 1960s, or between the Minnesota school and everyone else in the 1970s and early 1980s. People disagree about issues and science, of course, and they spend their time in seminar rooms and at conferences getting pretty heated about economics. But I think the level of mutual respect is actually relatively high. There seem to be more serious disputes, for example, between structural and astructural labor economists than among macroeconomists.

Back in the day, there was a revolution in macro, beginning with the Phelps volume, and Lucas's "Expectations and the Neutrality of Money." At the time, this revolution was widely-misperceived as a fundamentally conservative movement. It was actually a nerd revolution. The people who led it were an inarticulate and socially awkward bunch who were not let into (or were kicked out of) the Ivy League. They had to persevere outside of the mainstream, in underdog places like Carnegie-Mellon, Rochester, and the University of Minnesota, not to mention the Federal Reserve Bank of Minneapolis.

What these people had on their side were mathematics, econometrics, and most of all the power of economic theory. There was nothing weird about what these nerds were doing - they were simply applying received theory to problems in macroeconomics. Why could that be thought of as offensive?

Since the 1970s, it is hard to identify a field called macroeconomics. People who call themselves macroeconomists have adopted ideas from game theory, mechanism design, general equilibrium theory, finance, information economics, etc. to study problems of interest to policymakers and the public at large. Sometimes it's hard to tell a macroeconomist from a labor economist, from someone working on industrial organization problems. What are "freshwater" and "saltwater" macro? No idea. In Paul Krugman's own department at Princeton, Richard Rogerson, who was a student of Ed Prescott's, resides with Nobu Kiyotaki, who was a student (or at least a coauthor) of Olivier Blanchard's. There are other macroeconomists there with PhDs from Chicago, Minnesota, and MIT. What school of thought drives that place? Beats me.

The truth is that we have all moved on from the macro world of the 1970s. Methods that seemed revolutionary in 1972 are the methods everyone in the profession uses now. The nerds who had trouble getting their papers published in 1972 went on to run journals and professional organizations, and to win Nobel prizes. This isn't some "cult that has taken over half the field," it's the whole ball of wax. Rotten? No way!

Economic science does an excellent job of displacing bad ideas with good ones. It's happening every day. For every person who places obstacles in the way of good science to protect his or her turf, there are five more who are willing to publish innovative papers in good journals, and to promote revolutionary ideas that might be destructive for the powers-that-be. The state of macro is sound - not that we have solved all the problems in the world, or don't need a good revolution.

A Cartoon for the Pigou Club

Asness on Buffett

Warren may be a great investor, but he really doesn't cut it as a policy wonk.

Thursday, December 13, 2012

Interpreting the Fed

My friend and sometime coauthor Larry Ball sends me his quick analysis of the Federal Reserve's recent announcement:

I think the FOMC announcement is big news: for the first time, the Fed clearly says it will be more dovish in the future than the pre-crisis Taylor Rule (TR) dicates.

In my estimation, the pre-crisis TR is something like the following for the real interest rate r:

r = 2.0 - (1.5)(u-u*) + (0.5)(pi-2.0).

Let’s say u* is still 5.0. Then if u=6.5 and pi=2.5, the TR says r = 0, which implies the nominal interest rate is i = 2.5. Yet the Fed says that i will still be zero!

Some argue that u* has risen above 5.0. That would raise the i implied by the TR, strengthening the conclusion that the Fed’s new rule is more dovish than the TR.

Some argue that r* [the constant term in the TR] has fallen from 2.0 to 1.0. I doubt it, but even with that change, the TR still implies i = 1.5. My conclusion about dovishness is robust.

This deviation from the TR has not happened since the TR was discovered. In particular, the Fed was NOT more dovish than the TR in 2003. I believe the numbers for 2003 are roughly u=6.0, u*=5.0, and pi=1.0. For the TR shown above, the 2003 numbers imply r =0 and i=1.0, which is about the same as the actual i.

It is not clear whether the Fed’s announcement of future dovishness will have significant effects today. The efficacy of announcements about future monetary policy is unproven.