Monday, June 20, 2011

Krugman on Keynes and his message

In a paper prepared for the Cambridge conference commemorating the 75th anniversary of the publication of The General Theory of Employment, Interest and Money, Krugman argues that “What matters is what we make of Keynes, not what he ‘really’ meant.”

I’d divide Keynes readers into two types: Chapter 12ers and Book 1ers. Chapter 12 is, of course, the wonderful, brilliant chapter on long-term expectations, with its acute observations on investor psychology, its analogies to beauty contests, and more. Its essential message is that investment decisions must be made in the face of radical uncertainty to which there is no rational answer, and that the conventions men use to pretend that they know what they are doing are subject to occasional drastic revisions, giving rise to economic instability. What Chapter 12ers insist is that this is the real message of Keynes, that all those who have invoked the great man’s name on behalf of quasi-equilibrium models that push this insight into the background, from John Hicks to Paul Samuelson to Mike Woodford, have violated his true legacy.

Part 1ers, by contrast, see Keynesian economics as being essentially about the refutation of Say’s Law, about the possibility of a general shortfall in demand. And they generally find it easiest to think about demand failures in terms of quasi-equilibrium models in which some things, including wages and the state of long-term expectations in Keynes’s sense, are held fixed, while others adjust toward a conditional equilibrium of sorts. They draw inspiration from Keynes’s exposition of the principle of effective demand in Chapter 3, which is, indeed, stated as a quasi-equilibrium concept: “The value of D at the point of the aggregate demand function, where it is intersected by the aggregate supply function, will be called the effective demand”.

For what it’s worth, I’m basically a Part 1er, with a lot of Chapters 13 and 14 in there too, of which more shortly. Chapter 12 is a wonderful read, and a very useful check on the common tendency of economists to assume that markets are sensible and rational. But what I’m always looking for in economics is intuition pumps – ways to think about an economic situation that let you get beyond wordplay and prejudice, that seem to grant some deeper insight.

Krugman takes on some of the critics of Keynes and how they distort his message.

Here’s Robert Barro (2009): “John Maynard Keynes thought that the problem lay with wages and prices that were stuck at excessive levels. But this problem could be readily fixed by expansionary monetary policy, enough of which will mean that wages and prices do not have to fall.‖And if that’s all that it was about, the General Theory would have been no big deal.

But of course, it wasn’t just about that. Keynes’s critique of the classical economists was that they had failed to grasp how everything changes when you allow for the fact that output may be demand-constrained. They mistook accounting identities for causal relationships, believing in particular that because spending must equal income, supply creates its own demand and desired savings are automatically invested. And they had a theory of interest that thought solely in terms of the supply and demand for funds, failing to realize that savings in particular depend on the level of income, and that once you take this into account you need something else – liquidity preference – to complete the story.

Here’s Chicago’s John Cochrane (2009): “First, if money is not going to be printed, it has to come from somewhere. If the government borrows a dollar from you, that is a dollar that you do not spend, or that you do not lend to a company to spend on new investment. Every dollar of increased government spending must correspond to one less dollar of private spending. Jobs created by stimulus spending are offset by jobs lost from the decline in private spending. We can build roads instead of factories, but fiscal stimulus can’t help us to build more of both. This is just accounting, and does not need a complex argument about “crowding out.””

That’s precisely the position Keynes attributed to classical economists – “the notion that if people do not spend their money in one way they will spend it in another”. And as Keynes said, this misguided notion derives its plausibility from its superficial resemblance to the accounting identity which says that total spending must equal total income.

Here’s Niall Ferguson (in Soros et al 2009): “Now we’re in the therapy phase. And what therapy are we using? Well, it’s very interesting because we’re using two quite contradictory courses of therapy. One is the prescription of Dr. Friedman—Milton Friedman, that is —which is being administered by the Federal Reserve: massive injections of liquidity to avert the kind of banking crisis that caused the Great Depression of the early 1930s. I’m fine with that. That’s the right thing to do. But there is another course of therapy that is simultaneously being administered, which is the therapy prescribed by Dr. Keynes—John Maynard Keynes—and that therapy involves the running of massive fiscal deficits in excess of 12 percent of gross domestic product this year, and the issuance therefore of vast quantities of freshly minted bonds.

“There is a clear contradiction between these two policies, and we’re trying to have it both ways. You can’t be a monetarist and a Keynesian simultaneously—at least I can’t see how you can, because if the aim of the monetarist policy is to keep interest rates down, to keep liquidity high, the effect of the Keynesian policy must be to drive interest rates up.”

“After all, $1.75 trillion is an awful lot of freshly minted treasuries to land on the bond market at a time of recession, and I still don’t quite know who is going to buy them. It’s certainly not going to be the Chinese. That worked fine in the good times, but what I call “Chimerica”, the marriage between China and America, is coming to an end. Maybe it’s going to end in a messy divorce.”

What’s wrong with this line of reasoning? It’s exactly the logical hole Keynes pointed out, namely that the schedules showing the supply and demand for funds can only be drawn on the assumption of a given level of income.

As Hicks told us – and as Keynes himself says in Chapter 14 – what the supply and demand for funds really give us is a schedule telling us what the level of income will be given the rate of interest. That is, it gives us the IS curve …, which tells us where the central bank must set the interest rate so as to achieve a given level of output and employment. […] it’s possible that the interest rate required to achieve full employment is negative, in which case monetary policy is up against the zero lower bound, that is, we’re in a liquidity trap. That’s where America and Britain were in the 1930s – and we’re back there again.

Which brings me back to the argument that government borrowing under current conditions will drive up interest rates and impede recovery. What anyone who understood Keynes should realize is that as long as output is depressed, there is no reason increased government borrowing need drive rates up; it’s just making use of some of those excess potential savings – and it therefore helps the economy recover. To be sure, sufficiently large government borrowing could use up all the excess savings, and push rates up – but to do that the government borrowing would have to be large enough to restore full employment!