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Scott Sumner On Why Monetarism Might Be The Best Macro Perspective
See
Tyler Cowen and the Four Blind Men.
"Tyler Cowen has an excellent new video
out that looks at four schools of thought in business cycle theory,
with application to the Great Recession. I agree with most of the
specifics in the video, but differ in how to interpret the bigger
picture. I'll try to explain why.
Tyler starts with the metaphor of 4 blind men trying to understand
the nature of an elephant, each touching a different part of the beast.
The implication is that each of these four perspectives offers
something useful, and we should not confine our view to just one
perspective. The wise man takes an eclectic view of things.
I see the video as mixing up very different types of disagreement. Consider his description of the 4 views:
1. Keynesian: Focus on shortfall in aggregate demand, look at C+I+G factors.
2. Monetarist: Also look at AD, but see unstable monetary policy as the root cause.
3. Real Business Cycle: Slowing productivity growth before the 2008
recession helps explain the instability of AD. Taxes and subsidies
slowed the recovery.
4. Austrian: Government programs encouraged home lending, led to malinvestment. Fed policy was too stimulative before the recession.
To some extent, I agree with all four views. And yet I think
monetarism is true and Keynesianism, RBC and Austrianism are false. So
here's how I look at things:
1. One split is between nominal and real theories of the business
cycle. I believe the AS/AD model is true. This model suggests that
both nominal (AD) and real (AS) factors play a role in the cycle. I
believe AD shocks are the biggest factor in the US, and AS shocks are
the biggest factor in Venezuela. But each play a role in both
countries.
2. What do RBC proponents believe? Some RBC models do incorporate
sticky prices. But I recall Bennett McCallum arguing that if real
business cycle theory was not a denial of the importance of nominal
shocks, then it's hard to see how it's a distinctive theory at all.
After all, even in textbook Keynesian AS/AD models you see AS shocks
playing a role.
Furthermore, prominent RBC theorists often tend to scoff at claims
that high unemployment is caused by a lack of AD, and point to factors
such as government programs and regulations that create a disincentive
to work.
Tyler suggests that slowing productivity growth in some way have
contributed to a slowdown in AD during the Great Recession. I think
that's true, although I see the mechanism in a way that may differ from
his view. I believe slowing productivity growth lowered the equilibrium
interest rate. The Fed tried to keep up by lowering actual rates, but
did not do so rapidly enough, and money became tighter. So I don't see
that as evidence in support of hard-core RBC theory, in which AD shocks
are not very important because wages and prices are pretty flexible.
Again, not all RBC proponents take that extreme view, but it's the only
thing really distinctive about the theory. Otherwise it's two blind men
both touching the trunk of the elephant, and assigning different names
to the same appendage.
So this is why I believe that while slowing productivity
growth played a modest role in throwing monetary policy off course, and
government programs like 99 week extended unemployment benefits
slightly raised the natural rate of unemployment during the recovery,
the RBC model is fundamentally wrong. It's simply not a useful model.
It adds nothing useful to AS/AD analysis. We already knew that both
real and nominal shocks matter---the RBC proponents differ in
incorrectly exaggerating how much they matter.
3. Let's put aside the nominal/real argument, and think about
different nominal theories. The Keynesians are right that a lack of AD
led to the Great Recession. But that doesn't make the Keynesian theory
true. The real question is: What caused AD to fall sharply. The
Keynesian model suggests that the problem is the inherent instability of
capitalism, especially the propensity to invest. That may be a useful
theory under the gold standard, where the money supply can be thought of
as stable. But it's not a useful theory under a fiat money system with
monetary offset. The Fed is supposed to offset shocks to velocity, and
in the vast majority of cases it does so.
After the Soviet Union collapsed there was an increasing demand for
US currency notes. If the Fed had failed to accommodate that demand
then money would have become tighter, triggering a depression. No one
would have blamed Russian hoarding of US dollars, nor should they have
done so. The Fed would be expected to meet that extra demand for
liquidity. Similarly, they should have met the extra demand for
liquidity after the housing bubble burst, but instead they did just the
opposite during mid-2007 to mid-2008.
The Keynesian model is wrong under a fiat money system, because the
cause of recessions is unstable monetary policy, not the inherent
instability of capitalism. And that's true even though the Keynesians
are right about declining AD being the proximate cause of the recession,
and even about some of the factors that caused monetary policy to be
thrown off course, such as a decline in housing investment after the
"bubble" burst.
I think Tyler is wrong in claiming that each view offers something
valuable. Either their views overlap (the importance of AD shocks), or
their views directly contradict and can't both be right (i.e. the cause
of falling AD was the inherent instability of capitalism, vs. the view
that the cause was bad monetary policy.)
4. The one area where I slightly disagree with Tyler is his claim
that the Austrians de-emphasize AD, and prefer to let the market sort
things out on its own. Maybe that's correct, but I have trouble seeing
how. If Austrians believe that excessively expansionary Fed policy led
to an unsustainable boom with lots of bad investment, then they clearly
believe it's not enough to let the market sort things out, you need a
stable monetary regime. (Which may or may not involve the Fed.) That's
actually similar to the monetarist view.
And of course many monetarists agree with the Austrians that
government credit policies aimed at promoting housing were very
misguided. I believe that Austrianism is wrong as a business cycle
theory because the issues they point to (while correct) don't seem
powerful enough to cause a sizable recession.
To summarize, I don't like the way the video contrasts one wise man
with four blind men (not surprisingly, as I am one of the blind men.) I
believe it's possible to believe strongly in one view (monetarism in my
case) while being completely aware of the other perspectives, and even
agreeing that these factors play a role in the economy.
My reasons for rejecting these alternative views differ from one case
to another. In the case of Austrianism and RBC theory, I believe the
factors cited are simply too weak to explain the Great Recession. They
are grabbing the elephant's tail, not its body. In the case of
Keynesianism, I see the theory as being non-useful, because while it
correctly notes the importance of AD deficiency, it doesn't correctly
diagnose the reason for that deficiency--unstable monetary policy.
BTW, there is no such thing as passive and active monetary policies.
Policies that are passive in one dimension (say interest rates) are
active in another (say money supply.) So I'm not saying the Fed should
have rescued the economy, I'm saying they should have refrained from destabilizing the economy."
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