In the circles in which I travel, there is near-universal consensus that here in America our monetary philosopher-princes have made three serious mistakes. This consensus is almost always qualified by fervent declarations that we have been very well served by our Federal Reserve chairs and others since at least Paul Volcker's accession to the chair at the end of the table in the Eccles' Building's conference room, and that each of us who has not sat in that chair knows that he or she would have made worse mistakes, but nevertheless there is a consensus that mistakes were made when:
the Federal Reserve and the Treasury decided to nationalize AIG rather than to support AIG's counterparties last fall, allowing financiers to pretend that their strategies were fundamentally sound rather than things that would have shut down their firms had the Feds not paid AIG's bills.
the Federal Reserve and the Treasury decided to let Lehman Brothers go into an uncontrolled bankruptcy last fall in order to try to teach financiers that having an ill-capitalized counterparty was not riskless and that people should not expect the government to come to their rescue always.
the long-ago decision was made to eschew principles-based regulation and allow the shadow banking sector to grow unregulated with respect to its leverage and its compensation schemes in the belief that government regulation of finance should be minimal and that the government's guarantee of the commercial banking system was enough to keep us out of messes like the one we are currently in.
As I said, there is near-universal consensus in the circles in which I travel that these were mistakes and serious mistakes--and it is as certain as it is that the sun will rise in the east tomorrow morning that monetary policymakers will not make these mistakes again.
There is, however, active debate over whether there was a fourth mistake: whether Alan Greenspan's decision in 2001-2004 to push and keep nominal interest rates on Treasury securities very very low in order to try to keep the economy near full employment was a fourth mistake. Should Alan Greenspan have kept interest rates higher and triggered a much bigger recession with much higher unemployment back then in order to head off the growth of a housing bubble? If we push interest rates up, Alan Greenspan thought, millions of extra Americans will be unemployed and without incomes to no benefit--they will not enjoy the prolonged "staycations" they will be taking, and the rest of us won't have the stuff they could make. If we allow interest rates to fall, Alan Greenspan thought, these extra workers will be employed building houses and making things to sell to all the people whose incomes come from the construction sector and making things to sell to the people whose incomes come from making things to sell to people whose incomes come to the construction sector. Full employment is better than high unemployment if both can be accomplished without inflation, Alan Greenspan thought. If a bubble does develop, and if the bubble does not deflate but crashes, and if the crash threatens to cause a depression--well, Greenspan thought, then will be the time to deal with that, and the Federal Reserve is a very powerful institution with policy tools that can short-circuit that chain leading to catastrophe at any point.
With hindsight Alan Greenspan was wrong. Catastrophe does stare us in the face. His policies have crapped out. But not every good policy is certain to have a good outcome. The question is: was the bet that Alan Greenspan made a favorable one? Whenever in the future we find ourselves in a situation like 2003 should we try to keep the economy near full employment even at some risk of a developing bubble?
I am genuinely not sure which side I come down on in this debate. Central bankers have long recognized that it is imprudent to lower interest rates in pursuit of full employment if the consequence is an inflationary spiral in wages, resource prices, or consumer prices. On Tuesdays and Thursdays I think that going forward central bankers must now also recognize that it is imprudent to lower interest rates in pursuit of full employment when doing so risks an asset price bubble. On Mondays, Wednesdays, and Fridays I think that even with the extra information about the structure of the economy we have learned in the past two years that Greenspan's decisions in 2001-2004 were prudent and committed us to a favorable and acceptable bet. And I am writing this on a Friday.
I do, however, know that the way the issue is usually posed is wrong. People claim that the Greenspan Federal Reserve "aggressively pushed the interest rate below its natural level." But what is the natural level of the interest rate? Swedish economist Knut Wicksell defined the natural rate of interest in the 1920s: it is the interest rate at which, economy wide, desired investment is equal to desired savings and hence in which there is neither upward pressure for consumer price, resource price, and wage inflation to accelerate as aggregate demand outruns supply nor downward pressure on those three inflation rates as demand falls short of supply. On Wicksell's definition--which is the best, in fact, to my knowledge the only definition--the market interest rate was if anything above the natural interest rate in the early 2000s: not accelerating inflation but rather deflation threatened. The natural interest rate was very low because, as Ben Bernanke explained at the time, the world had a global savings glut (or, rather, a global investment deficiency).
You can argue--and on Tuesdays and Thursdays I will believe you--that Alan Greenspan's policies in the early 2000s were wrong. But you cannot argue that he aggressively pushed the interest rate below its natural level. The low interest rate was at its natural level. Rather, Greenspan's mistake--if it was a mistake--was his failure to overrule the market and aggressively push the interest rate up above its natural rate, thus deepening and prolonging the recession that started in 2001.
It's Friday, and I don't think Greenspan's failure to push the interest rate up above its natural rate to generate high unemployment and head off the growth of a mortgage-finance bubble was a mistake. There were mistakes--other places where the chain that has generated the catastrophe that faces us should have been interrupted. But today at least I don't think Greenspan's unwillingness to overrule the market's choice of the natural interest rate was one of them.