Dangling epsilons

Whenever I look at an estimation equation like this:
from this paper, I wonder what’s in that dangling epsilon term. In this equation we have Y’s on the left hand side. And I think to myself, “what kinds of things produce Y’s (or changes in Y’s)”. Now, Y is GDP and from my intro macro class I remember things like K’s and L’s produce Y’s. So given there’s no L’s and K’s in the equation, they must be in the dangling epsilon.

Changes in labor and capital are in the error term, but this is only a problem if changes in these factors of production are correlated with the other variables on the right hand side that aren’t in the error term.


It seems to me changes in labor and capital are correlated with changes in government expenditures (and military expenditures in particular… after all, the military is the worlds biggest employer). So while this paper claims to show the effect of military expenditures on output, it really shows that military expenditures create jobs and attract capital (they have an IV but as far as I can tell it doesn’t address this issue).

But can we salvage the overall message of the paper? Isn’t creating jobs and attracting capital exactly what we’re trying to do with fiscal stimulus? Yes, but not if it means that labor and capital is coming from other States. GDP is increasing in the States that have more military expenditures but is necessarily decreasing in the States that are losing workers and capital. Because these two effects cancel each other out, the “true” fiscal multiplier is less than the 1.5 estimated by this paper.

Increase inflation AND combat structural issues

Inflation is below target. Increasing output and decreasing or stagnant inflation is an indication that inflation expectations are becoming unanchored. That’s bad. Inflation should not spend too long, too far from its implicit target of 2%.

Structural unemployment is high right now. Instead of just dumbly extending UI benefits and scratching our heads on why unemployment among the young is increasing after three subsequent increases in the real minimum wage, we should do something about it.

Politically — I’m only guessing because I’m no expert — dealing with structural unemployment would be cheaper. The Fed, more than anyone else, knows how to increase inflation and they have figured out the cheapest way to do it. You might think, however, there are personnel issues at the Fed, i.e. too many hawks, that make “doing the right thing” impossible. And so, you might think, political pressure would have an effect on policy in the short run. I’m not sure why you think that. The FOMC meets only ever so often and they never take radically new action one way or the other. Policy stickiness is one of the most reliable facts about Fed policy. According to Goodfriend and King, even Volcker’s radical disinflation started over a year after he became chairman (and it took another 1/2 year to start to see employment effects). BTW, we’re not changing the chairman for a long while and even supposing Bernanke was suddenly reborn a Sumnerian, how do you think employers would react if the Fed announced bold action one way or the other? Ditto for massive institutional changes at the Fed.

In any case, with the Bernanke Put getting close to its strike price, the monetary policy car is going in the right direction. Given the current institutional framework, political pressure is not going to speed the car up.

But we can do more about structural unemployment. All it would take is for some enterprising think-tank researcher to buddy up with a promising young politician ((I’m thinking there may be an “only Nixon can go to China” effect here, but I’m sure a charming Democrat could pull it off too)) and to come up with a bold plan to deal with it. Radical changes to the UI system. Radical policies to deal with labor immobility. Radical interventions in the housing market. If engineered and sold to help reduce unemployment and as a package deal, these policies would be supported by both sides.

PS – We shouldn’t look to Europe for examples for good labor market institutions… the EU’s unemployment rate is higher than the US’s right now.

Setting expectations

Evans and Honkapohja’s work on learning in macro is important. Watch this to get a sense for what they’re doing:

But learning dynamics are not well understood empirically. Prof. Evans describes the dynamics under adaptive learning. Under rational expectations the economy would just pop to the good equilibrium. Under other learnings schemes the dynamics would be different. How do we know which dynamics describe the actual economy? We’d need to have empirical tests of the different learning regimes. We don’t have these tests.

In the same vein, Prof. Evans is just speculating about where the economy is right now in the phase diagram. He suggest we’re close to to the deflationary zone where things go to hell if the Fed raises interest rates. In fact, there’s no a priori way to know where we’re at in the diagram — we don’t have good measures of expectations.

(ht Thoma. BTW, Thoma says that Evan’s model shows increasing interest rates “increases rather than decreases the chance of a deflationary spiral”. They do no such thing. The little arrows on the phase diagram aren’t invariant to policy, see the paper figure 1. Suppose you’re close to the deflationary zone. Where you were before the policy may be in the deflationary zone after the policy, but your location after the policy is determined, in part, by the policy and it doesn’t have to be in the deflationary zone. Anyway, this probability could be computed as simulated comparative static, but Evan’s didn’t do this in his paper.)

Quit picking on Japan!

Here’s the per capita GDP for the G8 countries (relative to the USA):
You can take two lessons from this chart.
1) Japan hasn’t had bad monetary policy relative to, say, the continental European countries
2) Monetary policy just doesn’t matter in the long-run

Also, the more you stare at these real GDP per capita charts, the more you think the 1980s in Japan was an outlier (aka bubble).

What is structural unemployment?

There seems to be a disconnect between how economists (and Fed economists in particular) use this term and how bloggers (and left bloggers in particular) use it.

Some definitions:
“The unemployment resulting from wage rigidity and job rationing is sometimes called structural unemployment.” — Mankiw’s intermediate text

“Frictional unemployment [w.a. where the only other kind of unemployment they mention is cyclical unemployment] is the unemployment that exists when the economy is at full employment.” — Dornbusch, Fischer and Startz

“The part of unemployment associated with the institutional features of an economy, including hiring and firing costs and the structure of the unemployment compensation system.” — Jones’ intermediate text

There may be confusion about this term because there seems to be such a multitude of definitions (wikipedia’s definition talks about skill mismatch). I like Jones’ definition the best, but the point I want to make is that the lefty bloggers are reading more into these definitions than necessary.

There’s no reason to think the relationships between “wage rigidity”, “full employment”, “institutions” or “skill mismatch” and unemployment are constant over the business cycle. You can make good arguments that the mechanisms producing these relationships are responsive to overall conditions in the economy (I won’t). And… and!… estimates of structural unemployment suggest that it is time-varying: higher during recessions and lower during booms (anyone have a good cite for an estimate of time-varying NAIRU?).

When the Fed folks say structural unemployment is high right now (e.g. Altig or Kocherlakota), they’re not saying its permanently high. They’re not trying to pull an inception making us feel like permanent high unemployment is ok. They’re observing momentarily high structural unemployment that fits in a pattern consistent with historic experience.

Isn’t or Shouldn’t?

Sumner argues that if Krugman’s claim is true that the Fed is too conservative, that they will do whatever to curb inflation, then fiscal policy won’t work either. Fiscal policy moves the AD curve right, but the Fed will just move it back left.

Sumners argument only works if policy is not limited by the zero lower bound. Suppose the Fed’s conservative policy requires it to set interest rates at -2%. It can only set them to 0%. When fiscal policy moves the AD curve right, the Fed resets the target rate to -1%, say. Actual rates stay at 0%, the Fed can’t move the AD curve left and so fiscal policy is effective. Sumner says either “the Fed isn’t constrained to just set interest rates (e.g. currency interventions)” or “the Fed shouldn’t be constrained to just set interest rates”.

Its the “isn’t” and “shouldn’t” that is the core of the disagreement. Is there evidence for a political economy constraint on the Fed that prevents it from doing the right thing? As Tyler Cowen put it, assuming AD is too low, why isn’t the Fed following Sumner’s advice? If they’re not following Sumner’s advice then fiscal policy can be effective, right?

“My beef with Scott Sumner” OR “Dude, you’ve already won the debate!”

Pleasantries: brilliant blog. Anyone remotely interested in monetary policy, a.k.a. “the only remotely possible technocratic method to manage an economy”, should read it.

Ok. Prof. Sumner is absolutely right that the Fed made a mistake in fall of 2008. This is illustrated by the sharp decline in inflation expectations as illustrated in this graph (stolen from here):

But Sumner often slips from this valid critique into a claim that the Fed continues to make a mistake (e.g. here: “Throughout much of 2009 I kept challenging liberals to push harder for monetary stimulus.”). This is not a valid argument. For example, the Fed made a mistake in the late 1920’s trying to prick what they thought was a stock bubble. Their actions helped precipitate the Great Depression. Flippantly: this doesn’t mean policy is still too tight today. More relevantly: its not the reason why policy was too tight in 1930, 1931, 1932 and early 1933. The mistakes they made in those years where independent of the original mistake.

The sharp up-tick in inflation expectations through 2009, as seen in the graph above, suggests the Fed is no longer making a mistake; policy is no longer too tight.

What to do about high unemployment (illustrated below)?
First, unemployment has — hopefully! — topped out. This is more evidence that policy is, if not appropriately loose, at least loosening. Second, we don’t know the mechanisms linking macro policies to employment. The Fed doesn’t (and can’t!) determine the unemployment rate in any given month even if completely ignored inflation. Its hubris to suggest that it can. Third, even if money policy’s effects on inflation expectations is immediate, in a world of very slow moving wages, there’s long lags between policy changes and employment changes. The current policy could be producing improvements in the unemployment rate maybe today, maybe in three months, maybe in nine months… we don’t know.

All this said, I support Sumner’s goal of moving the Fed towards history dependent policy (aka “level targeting”). This policy, if even implementable, would make mistakes like the one the Fed made in fall 2008 less severe. I’m just not sure why Prof. Sumner insists on arguing policy is still too tight today, nearly 16 months later, when he doesn’t need to in order to make a case for this policy change.

Great Moderation, RIP?

Yuriy Gorodnichenko does some of the funnest research in macroeconomics. I’ve seen him talk about the Finnish Great Depression (subtitle: “From Russia with Love”) and his test of some theories of informational rigidity. His work is very empirically oriented, but takes theories seriously.

Today on voxeu he explores the question of whether the most recent recession implies the end of the Great Moderation. His answer: no.