IR Folks from Times Past

IR Folks from Times Past

Sunday, June 19, 2011

Keynesian Economics

From Paul Krugman, "Mr. Keynes and the Moderns," June 18, 2011:

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 quasiequilibrium 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.”

So who’s right about how to read the General Theory? Keynes himself weighed in, in his 1937 QJE article, and in effect declared himself a Chapter12er. But so what? Keynes was a great man, but only a man, and our goal now is not to be faithful to his original intentions, but rather to enlist his help in dealing with the world as best we can. . . .

The struggle to liberate ourselves from Say’s Law, to refute the “Treasury view” and all that, may have seemed like ancient history not long ago, but now that we’re faced with an economic scene reminiscent of the 1930s, it turns out that we’re having to fight those intellectual battles all over again. And the distinction between loanable funds and liquidity preference theories of the rate of interest – or, rather, the ability to see how both can be true at once, and the implications of that insight – seem to have been utterly forgotten by a large fraction of economists and those commenting on economics. . . .

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. . . .

If much of our public debate over fiscal policy has involved reinventing the same fallacies Keynes refuted in 1936, the same can be said of debates over international financial policy. Consider the claim, made by almost everyone, that given its large budget deficits the United States desperately needs continuing inflows of capital from China and other emerging markets. Even very good economists fall into this trap. Just last week Ken Rogoff declared that "loans from emerging economies are keeping the debt-challenged United States economy on life support.

Um, no: inflows of capital from other nations simply add to the already excessive supply of U.S. savings relative to investment demand. These inflows of capital have as their counterpart a trade deficit that makes America worse off, not better off; if the Chinese, in a huff, stopped buying Treasuries they would be doing us a favor. And the fact that top officials and highly regarded economists don’t get this, 75 years after the General Theory, represents a sad case of intellectual regression. . . . .

I constantly encounter the argument that our crisis was brought on by too much debt – which is largely my view as well – followed by the insistence that the solution can’t possibly involve even more debt.

Once you think about this argument, however, you realize that it implicitly assumes that debt is debt – that it doesn’t matter who owes the money. Yet that can’t be right; if it were, we wouldn’t have a problem in the first place. After all, the overall level of debt makes no difference to aggregate net worth – one person’s liability is another person’s asset.

It follows that the level of debt matters only if the distribution of net worth matters, if highly indebted players face different constraints from players with low debt. And this means that all debt isn’t created equal – which is why borrowing by some actors now can help cure problems created by excess borrowing by other actors in the past.

Suppose, in particular, that the government can borrow for a while, using the borrowed money to buy useful things like infrastructure. The true social cost of these things will be very low, because the spending will be putting resources that would otherwise be unemployed to work. And government spending will also make it easier for highly indebted players to pay down their debt; if the spending is sufficiently sustained, it can bring the debtors to the point where they’re no longer so severely balance-sheet constrained, and further deficit spending is no longer required to achieve full employment.

Yes, private debt will in part have been replaced by public debt – but the point is that debt will have been shifted away from severely balance-sheet-constrained players, so that the economy’s problems will have been reduced even if the overall level of debt hasn’t fallen.

The bottom line, then, is that the plausible-sounding argument that debt can’t cure debt is just wrong. On the contrary, it can – and the alternative is a prolonged period of economic weakness that actually makes the debt problem harder to resolve.