Plosser, Charles

"Bubble, Bubble, Toil and Trouble: A Dangerous Brew for Monetary Policy"

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Sound policymaking requires us to understand the limits of what we know. I doubt we could find enough agreement among policymakers or economists about the interpretation of asset-price movements to allow for stable, rule-based policymaking. In the absence of such a clearly stated rule, we risk uncertainty about central bank policy itself as well as its effect on the economy... Humility in policymaking requires that we respect the limits of our knowledge and not overreach, particularly when it involves over-riding market signals with policy actions.

Another challenge in addressing asset-price bubbles in practice is that contrary to many economic models, in reality there are many assets, not just one. And these assets have different characteristics. For example, equities are very different from homes. Misalignments or bubble-like behavior may appear in one asset class and not in others. But monetary policy is a blunt instrument. How would monetary policy go about pricking a bubble in technology stocks in 1998 and 1999 without wreaking havoc on investments underlying other asset classes?

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Indeed, I believe that we are discussing the question of asset prices and monetary policy today, at least in part, because Fed policy during mid-2000s “went off track.” John Taylor has argued forcefully that the Fed kept interest rates too low for too long from 2003 to 2005. As an erstwhile member of the Shadow Open Market Committee, I stood in this very room in 2003 and 2004, expressing concerns that the fears of deflation were excessive and that policy was probably too accommodative. The error may not have been that policymakers failed to pay attention to the fast upward rise in asset prices, but that they deviated from a systematic approach to setting nominal interests.