Scott Sumner’s three most recent posts (here, here, and here)have been really great, and I’ld like to comment on all of them. I will start with a comment on his post discussing whether the free market economy is stable; perhaps I will get around to the other two next week. Scott uses a 2009 paper by Robert Hetzel as the starting point for his discussion. Hetzel distinguishes between those who view the stabilizing properties of price adjustment as being overwhelmed by real instabilities reflecting fluctuations in consumer and entrepreneurial sentiment – waves of optimism and pessimism – and those who regard the economy as either perpetually in equilibrium (RBC theorists) or just usually in equilibrium (Monetarists) unless destabilized by monetary shocks. Scott classifies himself, along with Hetzel and Milton Friedman, in the latter category.
Scott then brings Paul Krugman into the mix:
Friedman, Hetzel, and I all share the view that the private economy is basically stable, unless disturbed by monetary shocks. Paul Krugman has criticized this view, and indeed accused Friedman of intellectual dishonesty, for claiming that the Fed caused the Great Depression. In Krugman’s view, the account in Friedman and Schwartz’s Monetary History suggests that the Depression was caused by an unstable private economy, which the Fed failed to rescue because of insufficiently interventionist monetary policies. He thinks Friedman was subtly distorting the message to make his broader libertarian ideology seem more appealing.
This is a tricky topic for me to handle, because my own view of what happened in the Great Depression is in one sense similar to Friedman’s – monetary policy, not some spontaneous collapse of the private economy, was what precipitated and prolonged the Great Depression – but Friedman had a partial, simplistic and distorted view of how and why monetary policy failed. And although I believe Friedman was correct to argue that the Great Depression did not prove that the free market economy is inherently unstable and requires comprehensive government intervention to keep it from collapsing, I think that his account of the Great Depression was to some extent informed by his belief that his own simple k-percent rule for monetary growth was a golden bullet that would ensure economic stability and high employment.
I’d like to first ask a basic question: Is this a distinction without a meaningful difference? There are actually two issues here. First, does the Fed always have the ability to stabilize the economy, or does the zero bound sometimes render their policies impotent? In that case the two views clearly do differ. But the more interesting philosophical question occurs when not at the zero bound, which has been the case for all but one postwar recession. In that case, does it make more sense to say the Fed caused a recession, or failed to prevent it?
Here’s an analogy. Someone might claim that LeBron James is a very weak and frail life form, whose legs will cramp up during basketball games without frequent consumption of fluids. Another might suggest that James is a healthy and powerful athlete, who needs to drink plenty of fluids to perform at his best during basketball games. In a sense, both are describing the same underlying reality, albeit with very different framing techniques. Nonetheless, I think the second description is better. It is a more informative description of LeBron James’s physical condition, relative to average people.
By analogy, I believe the private economy in the US is far more likely to be stable with decent monetary policy than is the economy of Venezuela (which can fall into depression even with sufficiently expansionary monetary policy, or indeed overly expansionary policies.)
I like Scott’s LeBron James analogy, but I have two problems with it. First, although LeBron James is a great player, he’s not perfect. Sometimes, even he messes up. When he messes up, it may not be his fault, in the sense that, with better information or better foresight – say, a little more rest in the second quarter – he might have sunk the game-winning three-pointer at the buzzer. Second, it’s one thing to say that a monetary shock caused the Great Depression, but maybe we just don’t know how to avoid monetary shocks. LeBron can miss shots, so can the Fed. Milton Friedman certainly didn’t know how to avoid monetary shocks, because his pet k-percent rule, as F. A. Hayek shrewdly observed, was a simply a monetary shock waiting to happen. And John Taylor certainly doesn’t know how to avoid monetary shocks, because his pet rule would have caused the Fed to raise interest rates in 2011 with possibly devastating consequences. I agree that a nominal GDP level target would have resulted in a monetary policy superior to the policy the Fed has been conducting since 2008, but do I really know that? I am not sure that I do. The false promise held out by Friedman was that it is easy to get monetary policy right all the time. It certainly wasn’t the case for Friedman’s pet rule, and I don’t think that there is any monetary rule out there that we can be sure will keep us safe and secure and fully employed.
But going beyond the LeBron analogy, I would make a further point. We just have no theoretical basis for saying that the free-market economy is stable. We can prove that, under some assumptions – and it is, to say the least, debatable whether the assumptions could properly be described as reasonable – a model economy corresponding to the basic neoclassical paradigm can be solved for an equilibrium solution. The existence of an equilibrium solution means basically that the neoclassical model is logically coherent, not that it tells us much about how any actual economy works. The pieces of the puzzle could all be put together in a way so that everything fits, but that doesn’t mean that in practice there is any mechanism whereby that equilibrium is ever reached or even approximated.
The argument for the stability of the free market that we learn in our first course in economics, which shows us how price adjusts to balance supply and demand, is an argument that, when every market but one – well, actually two, but we don’t have to quibble about it – is already in equilibrium, price adjustment in the remaining market – if it is small relative to the rest of the economy – will bring that market into equilibrium as well. That’s what I mean when I refer to the macrofoundations of microeconomics. But when many markets are out of equilibrium, even the markets that seem to be equilibrium (with amounts supplied and demanded equal) are not necessarily in equilibrium, because the price adjustments in other markets will disturb the seeming equilibrium of the markets in which supply and demand are momentarily equal. So there is not necessarily any algorithm, either in theory or in practice, by which price adjustments in individual markets would ever lead the economy into a state of general equilibrium. If we believe that the free market economy is stable, our belief is therefore not derived from any theoretical proof of the stability of the free market economy, but simply on an intuition, and some sort of historical assessment that free markets tend to work well most of the time. I would just add that, in his seminal 1937 paper, “Economics and Knowledge,” F. A. Hayek actually made just that observation, though it is not an observation that he, or most of his followers – with the notable and telling exceptions of G. L. S. Shackle and Ludwig Lachmann – made a big fuss about.
Axel Leijonhufvud, who is certainly an admirer of Hayek, addresses the question of the stability of the free-market economy in terms of what he calls a corridor. If you think of an economy moving along a time path, and if you think of the time path that would be followed by the economy if it were operating at a full-employment equilibrium, Leijonjhufvud’s corridor hypothesis is that the actual time path of the economy tends to revert to the equilibrium time path as long as deviations from the equilibrium are kept within certain limits, those limits defining the corridor. However, if the economy, for whatever reasons (exogenous shocks or some other mishaps) leaves the corridor, the spontaneous equilibrating tendencies causing the actual time path to revert back to the equilibrium time path may break down, and there may be no further tendency for the economy to revert back to its equilibrium time path. And as I pointed out recently in my post on Earl Thompson’s “Reformulation of Macroeconomic Theory,” he was able to construct a purely neoclassical model with two potential equilibria, one of which was unstable so that a shock form the lower equilibrium would lead either to a reversion to the higher-level equilibrium or to downward spiral with no endogenous stopping point.
Having said all that, I still agree with Scott’s bottom line: if the economy is operating below full employment, and inflation and interest rates are low, there is very likely a problem with monetary policy.