by Calculated Risk on 4/16/2009 08:06:00 PM

From San Francisco Fed President Janet Yellen: A Minsky Meltdown: Lessons for Central Bankers

... with the financial world in turmoil, Minsky’s work has become required reading. It is getting the recognition it richly deserves. The dramatic events of the past year and a half are a classic case of the kind of systemic breakdown that he—and relatively few others—envisioned.

Central to Minsky’s view of how financial meltdowns occur, of course, are “asset price bubbles.” This evening I will revisit the ongoing debate over whether central banks should act to counter such bubbles and discuss “lessons learned.” This issue seems especially compelling now that it’s evident that episodes of exuberance, like the ones that led to our bond and house price bubbles, can be time bombs that cause catastrophic damage to the economy when they explode.

Much of the speech is about Minsky, but here are some excerpts on bubbles and monetary policy:

[T]his evening I want to address another question that has been the subject of much debate for many years: Should central banks attempt to deflate asset price bubbles before they get big enough to cause big problems? Until recently, most central bankers would have said no. They would have argued that policy should focus solely on inflation, employment, and output goals—even in the midst of an apparent asset-price bubble. That was the view that prevailed during the tech stock bubble and I myself have supported this approach in the past. However, now that we face the tangible and tragic consequences of the bursting of the house price bubble, I think it is time to take another look.

Let me briefly review the arguments for and against policies aimed at counteracting bubbles. The conventional wisdom generally followed by the Fed and central banks in most inflation-targeting countries is that monetary policy should respond to an asset price only to the extent that it will affect the future path of output and inflation, which are the proper concerns of monetary policy. ... policy would not respond to the stock market boom itself, but only to the consequences of the boom on the macroeconomy.

However, other observers argue that monetary authorities must consider responding directly to an asset price bubble when one is detected. This is because—as we are witnessing—bursting bubbles can seriously harm economic performance, and monetary policy is hard-pressed to respond effectively after the fact. ...

What are the issues that separate the anti-bubble monetary policy activists from the skeptics? First, some of those who oppose such policy question whether bubbles even exist. ...

Second, even if bubbles do occur, it’s an open question whether policymakers can identify them in time to act effectively. Bubbles are not easy to detect because estimates of the underlying fundamentals are imprecise. ...

Now, even if we accept that we can identify bubbles as they happen, another question arises: Is the threat so serious that a monetary response is imperative? It would make sense for monetary policy makers to intervene only if the fallout were likely to be quite severe and difficult to deal with after the fact. ...

Still, just like infections, some bursting asset price bubbles are more virulent than others. The current recession is a case in point. As house prices have plunged, the turmoil has been transmitted to the economy much more quickly and violently than interest rate policy has been able to offset.

You’ll recognize right away that the assets at risk in the tech stock bubble were equities, while the volatile assets in the current crisis involve debt instruments held widely by global financial institutions. It may be that credit booms, such as the one that spurred house price and bond price increases, hold more dangerous systemic risks than other asset bubbles. By their nature, credit booms are especially prone to generating powerful adverse feedback loops between financial markets and real economic activity. It follows then, that if all asset bubbles are not created equal, policymakers could decide to intervene only in those cases that seem especially dangerous.

That brings up a fourth point: even if a dangerous asset price bubble is detected and action to rein it in is warranted, conventional monetary policy may not be the best approach. It’s true that moderate increases in the policy interest rate might constrain the bubble and reduce the risk of severe macroeconomic dislocation. In the current episode, higher short-term interest rates probably would have restrained the demand for housing by raising mortgage interest rates, and this might have slowed the pace of house price increases. In addition, as Hyun Song Shin and his coauthors have noted in important work related to Minsky’s, tighter monetary policy may be associated with reduced leverage and slower credit growth, especially in securitized markets. Thus, monetary policy that leans against bubble expansion may also enhance financial stability by slowing credit booms and lowering overall leverage.

Nonetheless, these linkages remain controversial and bubbles may not be predictably susceptible to interest rate policy actions. And there’s a question of collateral damage. Even if higher interest rates take some air out of a bubble, such a strategy may have an unacceptably depressing effect on the economy as a whole. There is also the harm that can result from “type 2 errors,” when policymakers respond to asset price developments that, with the benefit of hindsight, turn out not to have been bubbles at all. For both of these reasons, central bankers may be better off avoiding monetary strategies and instead relying on more targeted and lower-cost alternative approaches to manage bubbles, such as financial regulatory and supervisory tools. I will turn to that topic in just a minute.

In summary, when it comes to using monetary policy to deflate asset bubbles, we must acknowledge the difficulty of identifying bubbles, and uncertainties in the relationship between monetary policy and financial stability. At the same time though, policymakers often must act on the basis of incomplete knowledge. What has become patently obvious is that not dealing with certain kinds of bubbles before they get big can have grave consequences. This lends more weight to arguments in favor of attempting to mitigate bubbles, especially when a credit boom is the driving factor. I would not advocate making it a regular practice to use monetary policy to lean against asset price bubbles. However recent experience has made me more open to action. I can now imagine circumstances that would justify leaning against a bubble with tighter monetary policy. Clearly further research may help clarify these issues.

Another important tool for financial stability

Regardless of one’s views on using monetary policy to reduce bubbles, it seems plain that supervisory and regulatory policies could help prevent the kinds of problems we now face. Indeed, this was one of Minsky’s major prescriptions for mitigating financial instability. I am heartened that there is now widespread agreement among policymakers and in Congress on the need to overhaul our supervisory and regulatory system, and broad agreement on the basic elements of reform.
emphasis added

This is an interesting topic. I agree with Yellen's emphasis on regulation and oversight. I think it was easy to identify the surge in credit (especially home borrowing) and that lending standards had become very lax. That should have set off the alarm bells for regulators.