speeches · November 12, 2009
Regional President Speech
Charles L. Evans · President
O ce of the President Money Museum
Last Updated: 12 01 09
Should Monetary Policy Prevent Bubbles?
Conference Banque de France - Federal Reserve Bank of Chicago
"Asset Price Bubbles and Monetary Policy"
Paris, France
I would like to thank Deputy Governor Jean Pierre Landau, Benoit Mojon, and the Banque de France for organizing this timely
conference on asset price bubbles and monetary policy And I would like to thank two of our Chicago Fed sta ers—Jonas
Fisher and Gadi Barlevy—who helped Benoit put together such an interesting program It's been a pleasure for me to be in the
audience, and now, I will share my thoughts with you on this important topic
Let me emphasize that the views that I am presenting today are my own and not necessarily those of the Federal Open Market
Committee or my other colleagues in the Federal Reserve System
The nancial crisis we have experienced during the past two years has challenged the conventional view on how monetary
policy should respond to asset price movements Before the crisis, the common view was that a central bank should not react
to asset price movements, except to the extent that they a ect forecasts for in ation and the output gap A central bank would
instead stand ready to respond if and when a collapse in the prices of some assets threatened its ability to meet its policy
mandates Now, in the aftermath of the crisis, there are increasing calls for central banks to be more proactive in responding to
signs that an asset bubble may have emerged This notion is often described as an imperative to "lean against a bubble,"
meaning that the central bank should act to lower asset prices that, by historical standards, seem unusually high
Today, I would like to o er my position on this question I agree that the severity of the recent crisis argues against simply
waiting and mopping up after the fact if and when the prices of some assets do collapse But the type of proactive response by
a central bank that I envision is not well captured by the expression "leaning against a bubble " I prefer to see policy reacting to
apparent exuberance in asset markets and the problematic risk exposure this could create, rather than initiating action out of a
strong conviction that these particular assets are overvalued In addition, the expression "leaning against a bubble" evokes
polices that are aimed at achieving some targeted decline in asset prices In contrast, I view the goal of intervention as insuring
that exuberance in asset markets does not ultimately threaten the nancial system or contribute to nancial distress
Let me elaborate This will help explain why the conventional view of how policy ought to respond to bubbles has changed in
the wake of the nancial crisis The original case for why central banks should not respond to bubbles relies on two arguments
The rst holds that it is virtually impossible to determine whether an asset is trading above its fundamental value, certainly not
1
in real time and often not even after the fact The second argument holds that monetary policy as a tool is too blunt to prick
bubbles e ectively This is because monetary policy cannot be targeted precisely, and will a ect other nancial and
macroeconomic variables beyond just the set of asset prices in question In addition, the typical changes in interest rates that a
2
central bank might contemplate are likely to be too small to produce big changes in asset prices
Does the recent crisis justify revising this view? On the one hand, the crisis has certainly taught us a great deal about asset
price booms and busts We've learned, for example, that we must be attuned to the warning signs that might indicate potential
3
dangers in housing markets But does this mean we should be more con dent in our ability to easily and de nitively sort out
in real time whether a rapid increase in asset prices is associated with overvaluation? I am skeptical Each new episode is likely
it
to involve its own idiosyncratic features—enough to bring a new chorus proclaiming that "this time is di erent" and arguing
that we are not in fact facing a bubble As Carmen Reinhart and Ken Rogo remind us in their recent book, this pattern has
4
been going on for at least eight centuries As for the bluntness of monetary policy tools, I don't think the crisis has
demonstrated that the typical levers of monetary policy are any less blunt than we used to think
Instead, it seems it is the severity of the crisis, and the desire to not let one like it reoccur, that has encouraged people to
contemplate alternative policy responses Certainly, the crisis ought to have sobered us to the thought that asset price collapses
are always su ciently manageable after the fact But if the ultimate desire is to reduce the likelihood of such crises, our policy
response should focus on achieving nancial stability rather than on identifying and purging asset bubbles per se An
appropriate policy response may entail responding to bubbles, but I would argue that this should only be a means to achieving
the broader goal of nancial stability, rather than an end in and of itself Indeed, I am concerned that some policies may not
receive enough attention if we frame the lessons from the recent crisis too narrowly in terms of leaning against a bubble
So what steps should we take to reduce the chances of another nancial crisis? Part of the answer lies in structural
prescriptions The formulation of such frameworks will not be easy, and would greatly bene t from further research on how
nancial markets interact with real economic activity Researchers in both macroeconomics and nance have a good deal of
work to do on this score But I am hopeful that this research can help identify which environments might best reduce the
chance that nancial markets trigger ruinous crises, as well as determine what policy instruments we should add to our toolkit
At this point, I think that regulatory policy provides the most promise For one, it is important to improve resolution
procedures for nancial institutions in the event of insolvency This includes requiring rms to formulate contingency plans
that would be used in the event of their failure Doing so should reduce the chances that the collapse of a particular institution
will threaten the broader nancial system Just as importantly, these plans also would improve discussions between supervisors
and institutions This would facilitate horizontal reviews and in so doing help rst identify and then reduce potential systemic
risk exposures
At the same time, maintaining nancial stability is also likely to involve more-proactive, state-contingent measures, that is,
policies that vary with economic conditions For example, when faced by several indications that asset markets may be
exuberant, we might consider increasing capital requirements This might be either for nancial institutions as a whole or for
speci c institutions that choose to hold assets for which there is concern of a price collapse These requirements should serve
as a cushion if purchases of these assets result in losses They may also end up putting downward pressure on asset prices and,
at some point, even eliminate speculative excesses Here I have in mind theories of bubbles that are due to so-called agency
problems, where those who trade assets are acting as agents on behalf of others and cannot be perfectly monitored These
models, such as the models in the papers presented at the conference by Gadi Barlevy and Xavier Ragot, suggest that forcing
agents to stake more of their own resources could provide a strong disincentive for market participants to purchase overvalued
5
assets, possibly de ating a bubble that has already emerged
That said, it is important to stress that lowering asset prices would not be the direct intent of these policies and, therefore, not
the way we should judge their success We should consider an intervention successful if it helps to safeguard nancial
institutions and the real economy in the event that asset prices collapse, not if it manages to lower asset prices to better re ect
the true worth of the underlying assets In fact, we are unlikely to ever know if we accomplished the latter
One advantage of using nancial stability as our metric is that it does not require a central bank to take a stand on whether the
assets in question are overvalued Rather, the responses would be implemented whenever there are concerns that asset prices
may experience a sharp decline in the future, regardless of whether this decline is driven by fundamentals or by the bursting of
an asset bubble
I should note that some policymakers have recently expressed openness to the notion of leaning against bubbles The proposals
I just outlined are not out of scope with some of their thinking This is because they, too, often give regulatory policy a
6
prominent role Thus, while I might motivate and describe the appropriate policy response somewhat di erently, my
recommendation does not represent a radical departure from what others have argued
In closing, let me return to the broader themes of the conference In the past, economists used to debate whether bubbles were
even possible The research discussed here shows that there are conditions under which bubbles can unequivocally occur, even
among fully rational market participants, and that in some cases it might be desirable to burst them But what these papers do
not show is how central banks can reliably identify bubbles The best they can o er are useful warning signs, such as those in
7
the paper that Carsten Detken will present tomorrow As long as we can't detect bubbles with great con dence, it seems
unwise to adopt ghting them as a policy objective, even if only sparingly Instead, it seems better to commit to what central
banks are already mandated to do: preserve the safety and soundness of the nancial system at all times, including when there
is apparent exuberance in asset markets
I would like to acknowledge the help of the following Chicago Fed sta in preparing these remarks: Dan Sullivan, Spencer
Krane, and Gadi Barlevy
1
For example, in Peter M Garber, 2000, Famous First Bubbles: The Fundamentals of Early Manias, Cambridge, MA: MIT
Press, the author revisits three historical episodes that are commonly described as bubbles Garber concludes that in all three,
price movements can be explained by changes in the expectations of fundamentals by market participants Ellen McGrattan and
Edward Prescott similarly argue that the rise in the stock market prior to the 1929 crash was not a bubble; see Ellen
McGrattan and Edward Prescott, 2003, "Testing for stock market overvaluation undervaluation," in Asset Price Bubbles: The
Implications for Monetary, Regulatory, and International Policies, William C Hunter, George G Kaufman, and Michael
Pomerleano eds , Cambridge, MA: MIT Press, pp 271–276
2
The notion of a policy being too blunt because it can a ect many variables in addition to asset prices is usually attributed to
Bernanke and Gertler; see Ben Bernanke and Mark Gertler, 1999, "Monetary policy and asset price volatility," Economic
Review, Federal Reserve Bank of Kansas City, Fourth Quarter, pp 17–51 The notion of a policy being too blunt because it is
ine ective has been raised by Greenspan; see Alan Greenspan, 2002, "Central bank perspectives on stabilization policy—
Articles from the bank's Economic Policy Symposium, ‘Rethinking Stabilization Policy,’" Economic Review, Federal Reserve
Bank of Kansas City, Fourth Quarter, pp 5–12 See also Frederic S Mishkin, 2008, "How should we respond to asset price
bubbles?," speech at the Wharton Financial Institutions Center and Oliver Wyman Institute's Annual Financial Risk Roundtable,
Philadelphia, May 15
3
In a November 2008 speech, Don Kohn o ers an insightful discussion of how his view of asset bubbles was informed by the
crisis, including whether we can have advance warning that certain markets are subject to bubbles before the prices of these
assets decline; see Donald L Kohn, 2008, "Monetary policy and asset prices revisited," speech at the Cato Institute's 26th
Annual Monetary Policy Conference, Washington, DC, November 19
4
Carmen M Reinhart and Kenneth S Rogo , 2009, This Time Is Di erent: Eight Centuries of Financial Folly, Princeton, NJ:
Princeton University Press Reinhart and Rogo go on to argue that since these episodes are so similar, contrarian claims
should be refutable with evidence from various advance indicators of such crises By contrast, Caballero and Kurlat argue that
crises are nearly impossible to predict; see Ricardo J Caballero and Pablo Kurlat, 2009, "The ‘surprising’ origin and nature of
nancial crises: A macroeconomic policy proposal," paper at the Economic Policy Symposium, Financial Stability and
Macroeconomic Policy, Jackson Hole, WY, August 20–22 This debate underscores the point I wish to make: that making the
case that we are facing a bubble is likely to be di cult, since it will always be possible to argue about the relevance of
indicators that predicted crises in the past
5
Gadi Barlevy, 2009, "A leverage–based model of speculative bubbles," paper at Banque de France and Federal Reserve Bank of
Chicago conference, Asset Price Bubbles and Monetary Policy, Paris, November 13; and Simon Dubecq, Benoit Mojon, and
Xavier Ragot, 2009, "Risk shifting, fuzzy capital requirements and the build up of nancial fragility," paper at Banque de France
and Federal Reserve Bank of Chicago conference, Asset Price Bubbles and Monetary Policy, Paris, November 13 The original
work on bubbles and agency problems was done by Franklin Allen and Gary Gorton, 1993, "Churning bubbles," Review of
Economic Studies, Vol 60, No 4, pp 813–836, and Franklin Allen and Douglas Gale, 2000, "Bubbles and crises," Economic
Journal, Vol 110, No 460, pp 236–255; however, they do not emphasize the role of capital requirements in avoiding bubbles
in these papers
6
See William Dudley 2009, "Lessons learned from the nancial crisis," remarks at the Eighth Annual BIS conference, Basel,
Switzerland; Gary H Stern, 2009, remarks to the Helena business leaders, Helena, MT, July 9; Janet L Yellen 2009, panel
discussion for the Federal Reserve Board Journal of Money, Credit, and Banking, JMCB conference, Financial Markets and
Monetary Policy, Washington, DC, June 5; and Janet L Yellen, 2009, "A Minsky meltdown: Lessons for central bankers," speech
at the 18th annual Hyman P Minsky Conference on the State of the U S and World Economies, Meeting the Challenges of the
Financial Crisis, Levy Economics Institute of Bard College, New York City, April 16
7
Lucia Alessi and Carsten Detken, 2009, Real Time Early Warning Indicators for Boom–Bust Asset Price Cycles, paper at
Banque de France and Federal Reserve Bank of Chicago conference, Asset Price Bubbles and Monetary Policy, Paris, November
14
Note: Opinions expressed in this article are those of Charles L Evans and do not necessarily re ect the views of the
Federal Reserve Bank of Chicago or the Federal Reserve System
Cite this document
APA
Charles L. Evans (2009, November 12). Regional President Speech. Speeches, Federal Reserve. https://whenthefedspeaks.com/doc/regional_speeche_20091113_charles_l_evans
BibTeX
@misc{wtfs_regional_speeche_20091113_charles_l_evans,
author = {Charles L. Evans},
title = {Regional President Speech},
year = {2009},
month = {Nov},
howpublished = {Speeches, Federal Reserve},
url = {https://whenthefedspeaks.com/doc/regional_speeche_20091113_charles_l_evans},
note = {Retrieved via When the Fed Speaks corpus}
}