Alan Greenspan defends monetary policy during his reign as Chair of the Fed. He says the Fed's low interest rates did not play a major role in creating the subprime crisis, instead, factors such as the fall of the Berlin Wall were much more important:
The Roots of the Mortgage Crisis, by Alan Greenspan, Commentary, WSJ [Free Link]: On Aug. 9, 2007, and the days immediately following, financial markets in much of the world seized up. ... Over the past five years, risk had become increasingly underpriced as market euphoria, fostered by an unprecedented global growth rate, gained cumulative traction.
The crisis was thus an accident waiting to happen. If it had not been triggered by the mispricing of securitized subprime mortgages, it would have been produced by eruptions in some other market. As I have noted elsewhere, history has not dealt kindly with protracted periods of low risk premiums.
The root of the current crisis, as I see it, lies back in the aftermath of the Cold War, when the economic ruin of the Soviet Bloc was exposed with the fall of the Berlin Wall. Following these world-shaking events, market capitalism quietly, but rapidly, displaced much of the discredited central planning that was so prevalent in the Third World.
A large segment of the erstwhile Third World, especially China, replicated the successful economic export-oriented model of the so-called Asian Tigers ... to unleash explosive economic growth. ...
The surge in competitive, low-priced exports from developing countries ... flattened labor compensation in developed countries, and reduced the rate of inflation expectations..., including those inflation expectations embedded in global long-term interest rates.
In addition, there has been a pronounced fall in global real interest rates since the early 1990s, which, of necessity, indicated that global saving intentions chronically had exceeded intentions to invest. ... Asset prices accordingly moved dramatically higher. Not only did global share prices recover from the dot-com crash, they moved ever upward. ...
After more than a half-century observing numerous price bubbles evolve and deflate, I have reluctantly concluded that bubbles cannot be safely defused by monetary policy or other policy initiatives before the speculative fever breaks on its own. There was clearly little the world's central banks could do to temper this most recent surge in human euphoria...
I do not doubt that a low U.S. federal-funds rate in response to the dot-com crash, and especially the 1% rate set in mid-2003 to counter potential deflation, ... may have contributed to the rise in U.S. home prices. In my judgment, however, the impact on demand for homes financed with ARMs was not major.
Demand in those days was driven by the expectation of rising prices -- the dynamic that fuels most asset-price bubbles. If low adjustable-rate financing had not been available, most of the demand would have been financed with fixed rate, long-term mortgages. ...
I and my colleagues at the Fed believed that the potential threat of corrosive deflation in 2003 was real, even though deflation was not thought to be the most likely projection. We will never know whether the temporary 1% federal-funds rate fended off a deflationary crisis, potentially much more daunting than the current one. But I did fret that maintaining rates too low for too long was problematic. The failure of either the growth of the monetary base, or of M2, to exceed 5% while the fed-funds rate was 1% assuaged my concern that we had added inflationary tinder to the economy.
In mid-2004, as the economy firmed, the Federal Reserve started to reverse the easy monetary policy. I had expected ... a consequent increase in long-term interest rates, which might have helped to dampen the then mounting U.S. housing price surge. It did not happen. We had presumed long-term rates, including mortgage rates, would rise, as had been the case at the beginnings of five previous monetary policy tightening episodes, dating back to 1980. But after an initial surge in the spring of 2004, long-term rates fell back and, despite progressive Federal Reserve tightening through 2005, long-term rates barely moved.
In retrospect, global economic forces, which have been building for decades, appear to have gained effective control of the pricing of longer debt maturities. Simple correlations between short- and long-term interest rates in the U.S. remain significant, but have been declining for over a half-century... More generally, global forces, combined with lower international trade barriers, have diminished the scope of national governments to affect the paths of their economies.
Although central banks appear to have lost control of longer term interest rates, they continue to be dominant in the markets for assets with shorter maturities, where money and near monies are created. Thus central banks retain their ability to contain pressures on the prices of goods and services, that is, on the conventional measures of inflation.
The current credit crisis will come to an end when the overhang of inventories of newly built homes is largely liquidated, and home price deflation comes to an end. ... Very large losses will, no doubt, be taken as a consequence of the crisis. But after a period of protracted adjustment, the U.S. economy, and the world economy more generally, will be able to get back to business.
I don't think Bernanke would fully agree that the Fed has lost control of long-term rates:
Globalization and Monetary Policy, by Ben Bernanke: ...The empirical literature supports the view that U.S. monetary policy retains its ability to influence longer-term rates and other asset prices. Indeed, research on U.S. bond yields across the whole spectrum of maturities finds that all yields respond significantly to unanticipated changes in the Fed’s short-term interest-rate target and that the size and pattern of these responses has not changed much over time (Kuttner, 2001; Andersen and others, 2005; and Faust and others, 2006). Empirical studies also find that U.S. monetary policy actions retain a powerful effect on domestic stock prices. ...
I draw two conclusions... First, the globalization of financial markets has not materially reduced the ability of the Federal Reserve to influence financial conditions in the United States. But, second, globalization has added a dimension of complexity to the analysis of financial conditions and their determinants, which monetary policy makers must take into account.
The Fed did what it needed to do in 2003 to keep the economy moving forward, but that doesn't mean the policy could not have been improved. In any case, the policy, however necessary, had subsequent consequences that Greenspan seems unwilling to take responsibility for. In addition, the role that his laissez faire attitude may have had in blocking regulatory interventions that might have prevented or attenuated the crisis is conveniently omitted from the story Greenspan tells. Was the crisis his fault? I wouldn't go that far. Could he have done more to prevent it or reduce its severity? Here I think the answer is yes.
Update: The WSJ's Economics blog summarizes reaction to Greenspan's column.