Mark Thoma reports Janet Yellen's views on the housing bubble:
Economist's View: Yellen: There is a Bubble But Don't Pop It With Monetary Policy: [W]hile I'm certainly not predicting anything about future house price movements, I think it's obvious that the housing sector represents a risk to the U.S. outlook.
This brings me to the debate about how monetary policy should react to unusually high prices of houses--4or other assets, for that matter. ... As a starting point, the issue is not whether policy should react at all; I believe there is quite general agreement that policy should be calibrated to the wealth effects of house prices on output and inflation. The debate lies in determining when, if ever, policy should be focused on deflating the asset price bubble itself. In my view, the ... decision to deflate an asset price bubble rests on positive answers to three questions. First, if the bubble were to collapse on its own, would the effect on the economy be exceedingly large? Second, is it unlikely that the Fed could mitigate the consequences? Third, is monetary policy the best tool to use to deflate a house-price bubble?
My answers to these questions in the shortest possible form are, "no," "no," and "no." ... In answer to the first question on the size of the effect, it could be large enough to feel like a good-sized bump in the road, but the economy would likely to be able to absorb the shock... In answer to the second question on timing, the spending slowdown that would ensue is likely to kick in gradually... That would give the Fed time to cushion the impact with an easier policy. In answer to the third question on whether monetary policy is the best tool to deflate a house-price bubble, ... For one thing, no one can predict exactly how much tightening would be needed, or by exactly how much the bubble should be reduced. Beyond that, a tighter policy to deflate a housing bubble could impose substantial costs on other sectors of the economy that would lead to equally unwelcome imbalances. Finally, it's possible that other strategies, such as tighter supervision or changes in financial regulation, would not only be more tailored to the problem, but also less costly to the economy. Taking all of these points into consideration, it seems that the arguments against trying to deflate a bubble outweigh those in favor of it. ... But let me stress that the debate surrounding these issues is still very much alive.