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For release on delivery
10:30 a.m. EST
January 3, 2010

Monetary Policy and the Housing Bubble
by
Ben S. Bernanke
Chairman
Board of Governors of the Federal Reserve System
at the
Annual Meeting of the American Economic Association
Atlanta, Georgia

January 3, 2010

The financial crisis that began in August 2007 has been the most severe of the
post-World War II era and, very possibly--once one takes into account the global scope
of the crisis, its broad effects on a range of markets and institutions, and the number of
systemically critical financial institutions that failed or came close to failure--the worst in
modern history. Although forceful responses by policymakers around the world avoided
an utter collapse of the global financial system in the fall of 2008, the crisis was
nevertheless sufficiently intense to spark a deep global recession from which we are only
now beginning to recover.
Even as we continue working to stabilize our financial system and reinvigorate
our economy, it is essential that we learn the lessons of the crisis so that we can prevent it
from happening again. Because the crisis was so complex, its lessons are many, and they
are not always straightforward. Surely, both the private sector and financial regulators
must improve their ability to monitor and control risk-taking. The crisis revealed not
only weaknesses in regulators’ oversight of financial institutions, but also, more
fundamentally, important gaps in the architecture of financial regulation around the
world. For our part, the Federal Reserve has been working hard to identify problems and
to improve and strengthen our supervisory policies and practices, and we have advocated
substantial legislative and regulatory reforms to address problems exposed by the crisis.
As with regulatory policy, we must discern the lessons of the crisis for monetary
policy. However, the nature of those lessons is controversial. Some observers have
assigned monetary policy a central role in the crisis. Specifically, they claim that
excessively easy monetary policy by the Federal Reserve in the first half of the decade
helped cause a bubble in house prices in the United States, a bubble whose inevitable

-2collapse proved a major source of the financial and economic stresses of the past two
years. Proponents of this view typically argue for a substantially greater role for
monetary policy in preventing and controlling bubbles in the prices of housing and other
assets. In contrast, others have taken the position that policy was appropriate for the
macroeconomic conditions that prevailed, and that it was neither a principal cause of the
housing bubble nor the right tool for controlling the increase in house prices. Obviously,
in light of the economic damage inflicted by the collapses of two asset price bubbles over
the past decade, a great deal more than historical accuracy rides on the resolution of this
debate.
The goal of my remarks today is to shed some light on these questions. I will first
review U.S. monetary policy in the aftermath of the 2001 recession and assess whether
the policy was appropriate, given the state of the economy at that time and the
information that was available to policymakers. I will then discuss some evidence on the
sources of the U.S. housing bubble, including the role of monetary policy. Finally, I will
draw some lessons for future monetary and regulatory policies.1
U.S. Monetary Policy, 2002-2006
I will begin with a brief review of U.S. monetary policy during the past decade,
focusing on the period from 2002 to 2006. As you know, the U.S. economy suffered a
moderate recession between March and November 2001, largely traceable to the ending
of the dot-com boom and the resulting sharp decline in stock prices. Geopolitical
uncertainties associated with the terrorist attacks of September 11, 2001, and the invasion

1

My remarks will rely heavily on material drawn from Dokko and others (2009). However, neither those
authors nor my other colleagues in the Federal Reserve System are responsible for the interpretations and
conclusions I draw in these remarks.

-3of Iraq in March 2003, as well as a series of corporate scandals in 2002, further clouded
the economic situation in the early part of the decade.
Slide 1 shows the path, from the year 2000 to the present, of one key indicator of
monetary policy, the target for the overnight federal funds rate set by the Federal Open
Market Committee (FOMC). The Federal Reserve manages the federal funds rate, the
interest rate at which banks lend to each other, to influence broader financial conditions
and thus the course of the economy. As you can see, the target federal funds rate was
lowered quickly in response to the 2001 recession, from 6.5 percent in late 2000 to
1.75 percent in December 2001 and to 1 percent in June 2003. After reaching the thenrecord low of 1 percent, the target rate remained at that level for a year. In June 2004, the
FOMC began to raise the target rate, reaching 5.25 percent in June 2006 before pausing.
(More recently, as you know, and as the rightward portion of the slide indicates, rates
have been cut sharply once again.) The low policy rates during the 2002-06 period were
accompanied at various times by “forward guidance” on policy from the Committee. For
example, beginning in August 2003, the FOMC noted in four post-meeting statements
that policy was likely to remain accommodative for a “considerable period.”2
The aggressive monetary policy response in 2002 and 2003 was motivated by two
principal factors. First, although the recession technically ended in late 2001, the
recovery remained quite weak and “jobless” into the latter part of 2003. Real gross
domestic product (GDP), which normally grows above trend in the early stages of an
economic expansion, rose at an average pace just above 2 percent in 2002 and the first
2

In January 2004, the Committee expressed an intention to be “patient” regarding the removal of monetary
policy accommodation. In May 2004, a month before the Committee began to increase its target for the
federal funds rate, it said that accommodation was likely to be removed at a pace that would be
“measured.” For discussions of the potential benefits of such communication, particularly in the face of
possible deflationary risks, see Eggertsson and Woodford (2003) and Woodford (2007).

-4half of 2003, a rate insufficient to halt continued increases in the unemployment rate,
which peaked above 6 percent in the first half of 2003.3 Second, the FOMC’s policy
response also reflected concerns about a possible unwelcome decline in inflation. Taking
note of the painful experience of Japan, policymakers worried that the United States
might sink into deflation and that, as one consequence, the FOMC’s target interest rate
might hit its zero lower bound, limiting the scope for further monetary accommodation.
FOMC decisions during this period were informed by a strong consensus among
researchers that, when faced with the risk of hitting the zero lower bound, policymakers
should lower rates preemptively, thereby reducing the probability of ultimately being
constrained by the lower bound on the policy interest rate.4
Evaluating the Tightness or Ease of Monetary Policy
Although macroeconomic conditions certainly warranted accommodative policies
in 2002 and subsequent years, the question remains whether policy was nevertheless
easier than necessary. Since we cannot know how the economy would have evolved
under alternative monetary policies, any answer to this question must be conjectural.
One approach used by many who have addressed this question is to compare
Federal Reserve policies during this period to the recommendations derived from simple
policy rules, such as the so-called Taylor rule, developed by John Taylor of Stanford
University (Taylor, 1993). This approach is subject to a number of limitations, which are

3

Many saw the relatively weak recovery as reflecting a “capital overhang” left over from the rapid pace of
investment in information technology during the boom. According to this view, the capital overhang both
inhibited new capital investment and, by leading to ongoing productivity improvements, also limited the
need for employers to add workers to meet the relatively moderate increases in final demand that were
forthcoming. As noted in the text, geopolitical uncertainties as well as corporate scandals added to the
uncertainties faced by employers.
4
For discussion of the Japanese experience and appropriate policies near the zero bound, see Fuhrer and
Madigan (1997), Reifschneider and Williams (2000), and Ahearne and others (2002).

-5important to keep in mind.5 Notably, simple policy rules like the Taylor rule are only
rules of thumb, and reasonable people can disagree about important details of the
construction of such rules. Moreover, simple rules necessarily leave out many factors
that may be relevant to the making of effective policy in a given episode--such as the risk
of the policy rate hitting the zero lower bound, for example--which is why we do not
make monetary policy on the basis of such rules alone. For these reasons, even strong
proponents of simple policy rules generally advise that they be used only as guidelines,
not as substitutes for more complete policy analyses; and that, to ensure robustness, the
recommendations of a number of alternative simple rules should be considered (Taylor,
1999a). That said, as much of the debate about monetary policy after the 2001 recession
has made use of such rules, I will discuss them here as well.
The well-known Taylor rule relates the prescribed setting of the overnight federal
funds rate--the interest rate targeted by the FOMC in its making of monetary policy--to
two factors: (1) the deviation, in percentage points, of the current inflation rate from
policymakers’ longer-term inflation objective; and (2) the so-called output gap, defined
as the percentage difference between current output (usually defined as real GDP) and the
“normal” or “potential” level of output. In symbols, the standard form of the Taylor rule
is given by the equation shown in Slide 2. In this equation,
the policy interest rate in a given period t;
rate π from its target

in period t; and

actual real output y from potential output

5

is the prescribed value of

is the deviation of the actual inflation
, the “output gap,” is the deviation of
in period t. The parameters a and b are

Kohn (2007) discusses some of these limitations and anticipates some of the points made in my remarks
today.

-6positive numbers that describe how strongly the policy rate should respond to deviations
of inflation from its target and of output from its potential.
As we would expect, the Taylor rule tells policymakers that interest rates should
be higher when inflation is above target, (
potential,

0 , or when output is above its

0. Taylor (1993) estimated the long-run real value of the federal

funds rate to be about 2 percent. The equation for the Taylor rule accordingly shows that
when inflation and output are equal to their targets, the federal funds rate--which is
expressed here in nominal terms--should equal 2 plus the rate of inflation. Equivalently,
when inflation and output equal their targets, the real value of the federal funds rate
should equal 2 percent.
To make the Taylor rule equation shown in Slide 2 operational, one needs to
specify numerical values for the coefficients a and b, choose appropriate indicators of
inflation and output, and specify a target rate for inflation and a measure of potential
output. In his 1993 paper introducing his eponymous rule, Taylor suggested setting both
a and b equal to 0.5. So, for example, according to the original Taylor rule, if output
rises 1 percent relative to its potential, then, all else equal, the Federal Reserve should
raise its policy rate by 0.5 percent, or 50 basis points. Following Taylor’s suggestions for
parameter values, in Slide 3 we show by the dashed red line the values of the federal
funds rate implied by the Taylor rule for the period from 2000 to the present, with
inflation measured by the consumer price index (CPI), the Fed’s assumed inflation target
set to 2 percent, output measured by real GDP, and the output gap as estimated
retrospectively by the Federal Reserve’s primary forecasting model, the FRB/US model.

-7The Taylor rule prescription is juxtaposed with the actual path of the policy rate taken
from Slide 1, again shown in blue.
The comparison displayed in Slide 3 provides the most commonly cited evidence
that monetary policy was too easy during the period from 2002 to 2006, as the actual
federal funds rate is below the values implied by the Taylor rule--by about 200 basis
points on average over this five-year period (Taylor, 2007).
Of course, the validity of that conclusion depends on whether the specific
assumptions and measurements used to construct the Taylor rule’s policy prescription are
appropriate. Room for disagreement exists. For example, some empirical and simulation
evidence suggests that the responsiveness of policy to the output gap, given by the
parameter b in the Taylor rule equation, should be higher than the value of 0.5 originally
chosen by Taylor.6 Higher values of b lead the Taylor rule to recommend somewhat
lower policy rates during recessions and their aftermaths.
The prescriptions of the Taylor rule may also depend sensitively on how inflation
and the output gap are measured. The difficulties in measuring the output gap,
particularly in real time, are well known. The choice of inflation measure may also be
consequential. In his original 1993 paper, Taylor chose to measure inflation using the
GDP deflator. As noted, the Taylor rule policy prescription shown in Slide 3 is based on
the familiar CPI measure of inflation. For its part, during the past decade, the FOMC has
typically focused on inflation as measured by the price index for personal consumption
expenditures (PCE), because that measure is less dominated than is the CPI by the
imputed rent of owner-occupied housing, and for other technical reasons. As it happens,

6

Taylor (1999b) contains a set of studies comparing economic performance in a range of economic models
under alternative rules and parameter settings.

-8the choice of inflation measure matters for the interpretation of this episode, as alternative
measures gave policymakers somewhat different signals. Notably, core PCE inflation for
2003 was initially reported, in the first quarter of 2004, as having slowed to about
1 percent, and it appeared to be on a steep downward trajectory.7 These data heightened
concerns about deflation on the FOMC. In contrast, the CPI data released at the same
time showed core inflation for 2003 of about 2 percent. In this case, data revisions
ultimately raised estimates of PCE inflation for that period, implying that deflation was
less of a risk than was thought at the time. But that such revisions would occur could not
be known in advance, and policy decisions, of course, must be made based on the
information available at the time.
For my purposes today, however, the most significant concern regarding the use
of the standard Taylor rule as a policy benchmark is its implication that monetary policy
should depend on currently observed values of inflation and output. In particular, the
Taylor rule recommendation shown in Slide 3 relates the prescribed policy interest rate to
the inflation rate and output gap that correspond to the same quarter in which the policy
decision was made.8 However, because monetary policy works with a lag, effective
monetary policy must take into account the forecast values of the goal variables, rather
than the current values. Indeed, in that spirit, the FOMC issues regular economic
projections, and these projections have been shown to have an important influence on
policy decisions (Orphanides and Wieland, 2008).

7

Inflation measures are on a four-quarter basis. Core inflation excludes the prices of food and energy.
Because it excludes the most volatile components of the price index, core inflation was often used by the
FOMC as an indicator of the underlying trend of inflation.
8
More precisely, because inflation is measured on a four-quarter basis, the current inflation rate
corresponds to the rate of price increase over the current quarter and the prior three quarters.

-9The distinction between current and forecast values does not always matter much,
as (for example) high levels of inflation or output today may signal high levels of those
variables in the future. However, over the past decade, the distinction between current
and forecast inflation has been an important one. On several occasions during this
period, surges in energy prices led to increases in overall inflation. According to the
standard Taylor rule, whose policy prescription depends on the current value of inflation,
these episodes should have led to a significant tightening of monetary policy. However,
both the FOMC and private forecasters expected these increases in energy prices to
subside--correctly, as it turned out--and therefore did not much adjust their medium-term
forecasts for inflation. Consequently, policy was not tightened as much as would have
been called for by the standard Taylor rule. Put another way, the standard Taylor rule
makes no distinction between increases in inflation expected to be temporary and those
expected to be longer lasting. In practice, however, policymakers have responded less to
increases in inflation that they expect to be temporary, a reasonable strategy given that
monetary policy affects inflation only with a significant lag.
Slide 4 shows the quantitative implications of this point. The actual paths of the
policy rate, in blue, and the policy prescription implied by the standard Taylor rule, the
dashed red line, are the same as in Slide 3. Also shown, as a dotted green line, is the
monetary policy path prescribed by an alternative version of the Taylor rule that replaces
the current rate of inflation on the right-hand side with a forecast of inflation over the
current and subsequent three quarters. Forecasts are those that were actually made in real
time, that is, at the time at which the corresponding policy rate was chosen. For the
period through 2004, these forecasts are the staff forecasts (the so-called Greenbook

- 10 forecasts) that were prepared for each policy meeting. Because Greenbook forecasts for
the period after 2004 are not yet publicly available, from 2005 on the forecasts are
constructed from the publicly released, contemporaneous projections of FOMC
participants, using methods developed by Athanasios Orphanides and Volker Wieland
(2008).9 In addition, consistent with the practices of the FOMC, inflation is measured by
the PCE price index as was available in real time, instead of by the CPI.10
As Slide 4 shows, the alternative Taylor rule prescribes a path for policy that is
much closer to that followed throughout the decade, including recent years. In other
words, when one takes into account that policymakers should and do respond differently
to temporary and longer-lasting changes in inflation, monetary policy following the 2001
recession appears to have been reasonably appropriate, at least in relation to a simple
policy rule.
Which version of the Taylor rule--the standard version, that uses current values of
inflation, or the alternative version, that employs inflation forecasts--is the more reliable
guide? I have explained my preference for using inflation forecasts rather than actual
inflation in the policy rule: Monetary policy works with a lag, and therefore policy
decisions must be forward looking. One might still prefer the simplicity of the standard
Taylor rule that uses current inflation values. However, note from Slide 4 that a

9

FOMC projections between 2005 and 2007 are obtained from Monetary Policy Report to the Congress,
published in February and July (available at www.federalreserve.gov/monetarypolicy/mpr_default.htm);
projections for core inflation are converted to projections for headline inflation based on staff calculations
that in turn rely on energy futures prices. Starting in 2008, FOMC inflation forecasts, for both core and
headline inflation, become available four times each year in the Summary of Economic Projections (see, for
example, Board of Governors of the Federal Reserve System (2009), “Minutes of Federal Open Market
Committee, January 9, 21, and 29-30, 2008,” press release, February 20,
www.federalreserve.gov/newsevents/press/monetary/20080220a.htm).
10
In the same spirit, we also replace the output gap as measured retrospectively by the FRB/US model with
the output gap from that model as measured in real time. This change has no significant effect on the
policy prescriptions over most of the period.

- 11 proponent of the standard rule would have recommended that the FOMC raise the policy
rate to a range of 7 to 8 percent through the first three quarters of 2008, just after the
recession peak and just before the intensification of the financial crisis in September and
October--a policy decision that probably would not have garnered much support among
monetary specialists. In contrast, Slide 4 shows that the version of the Taylor rule based
on forecast inflation (in green dots) explains both the course of monetary policy earlier in
the past decade as well as the decision not to respond aggressively to what did in fact turn
out to be a temporary surge in inflation in 2008. This comparison suggests that the
Taylor rule using forecast inflation is a more useful benchmark, both as a description of
recent FOMC behavior and as a guide to appropriate policy.
Although monetary policy from 2002 to 2006 appears to have been reasonably
consistent with the Federal Reserve’s mandated goals of maximum sustainable
employment and price stability, we have not yet addressed the possibility that
accommodative policies--though perhaps appropriate for achieving medium-term
inflation and output goals--inadvertently contributed to the housing bubble. I turn now to
that question.
Monetary Policy and the Housing Bubble
To set the stage for the discussion, Slide 5 shows the annual increase in nominal
house prices from 1978 to the present.11 After some years of slow growth, U.S. house

11

These data are based on repeat sales of specific homes, which helps to correct for changes in the
composition of home sales, and include information on homes financed outside of the governmentsponsored enterprises, Fannie Mae and Freddie Mac.
An important, and perhaps underappreciated, issue is that measurement of house prices has
improved considerably since the early part of the past decade. The LoanPerformance index on which Slide
5 is based corrects for changes in the composition of sales through the use of repeat sales, as noted in the
text. During the first half of the past decade, however, the only publicly available house price indexes
making that important correction were based on data taken from mortgages purchased by the governmentsponsored enterprises, Fannie Mae and Freddie Mac. However, because they were based on homes

- 12 prices began to rise more rapidly in the late 1990s. Prices grew at a 7 to 8 percent annual
rate in 1998 and 1999, and in the 9 to 11 percent range from 2000 to 2003. Thus, the
beginning of the run-up in housing prices predates the period of highly accommodative
monetary policy. Shiller (2007) dates the beginning of the boom in 1998. On the other
hand, the most rapid price gains were in 2004 and 2005, when the annual rate of house
price appreciation was between 15 and 17 percent. Thus, the timing of the housing
bubble does not rule out some contribution from monetary policy.
To try to assess the importance of that possible contribution, in the remainder of
my remarks I will consider briefly two related questions. First, the cumulative increase in
housing prices shown in Slide 5 is quite large. Can accommodative monetary policies
during this period reasonably account for the magnitude of the increase in house prices
that we observed? If not, what does account for it? Second, house prices rose
significantly during this period in many industrialized countries, not just in the United
States. If monetary policy was an important source of house price appreciation in the
United States, it seems reasonable to expect that, in an international comparison,
countries with easier monetary policies should have been more likely to have significant
rises in house prices as well. Is that the case?
With respect to the magnitude of house-price increases: Economists who have
investigated the issue have generally found that, based on historical relationships, only a
small portion of the increase in house prices earlier this decade can be attributed to the

purchased using so-called conforming mortgages, these indexes missed price movements in many houses
financed with jumbo, alt-A, and subprime mortgages. See Dokko and others (2009).

- 13 stance of U.S. monetary policy.12 This conclusion has been reached using both
econometric models and purely statistical analyses that make no use of economic theory.
To demonstrate this finding in a simple way, I will use a statistical model
developed by Federal Reserve Board researchers that summarizes the historical
relationships among key macroeconomic indicators, house prices, and monetary policy
(Dokko and others, 2009). The statistical technique employed in this model, known as
vector autoregression, is familiar to econometricians who seek to analyze the joint
evolution of a collection of data series over time. The model incorporates seven
variables, including measures of economic growth, inflation, unemployment, residential
investment, house prices, and the federal funds rate, and it is estimated using data from
1977 to 2002.13 For our purposes, the value of such a model is that it can be used to
predict the behavior of any of the variables being studied, assuming that historical
relationships hold and that the other variables in the system take on their actual historical
values.
Slide 6 illustrates the application of this procedure to the federal funds rate and
housing prices over the period from 2003 to 2008. In the left panel of the figure, the solid
line shows the actual history of the federal funds rate. The shaded area in the figure is
constructed using the results of the statistical model; it shows the range of possible
outcomes that would be considered “normal” for the federal funds rate, assuming that the
other six variables included in the model took their actual values during the years 2003
through 2008. Values of the federal funds rate that fall in the shaded area are relatively

12

See, for example, Del Negro and Otrok (2007), Jarocinski and Smets (2008), Edge, Kiley, and Laforte
(2009), and Iacoviello and Neri (forthcoming).
13
See Dokko and others (2009) for details. The authors stop the sample in 2002 to exclude the period in
question.

- 14 “close to” (technically, within 2 standard deviations of) the corresponding forecast
values. In line with our earlier discussion, the left panel of the figure suggests that,
although monetary policy during the period following the 2001 recession was
accommodative, it was not inconsistent with the historical experience, given the
macroeconomic environment of the time.
The right panel of the figure shows the forecast behavior of house prices during
the recent period, taking as given macroeconomic conditions and the actual path of the
federal funds rate. As you can see, the rise in house prices falls well outside the
predictions of the model. Thus, when historical relationships are taken into account, it is
difficult to ascribe the house price bubble either to monetary policy or to the broader
macroeconomic environment.
A possible objection to this conclusion is that, because of changes in methods of
housing finance, the responsiveness of house prices to monetary policy may have been
different in the past decade than it was in the 1980s and 1990s. For example, during
2003 and 2004, about one-third of mortgage applications were for adjustable-rate
mortgage (ARM) products. Low policy rates feed through to monthly mortgage
payments more directly when the mortgage interest rate is adjustable and tied to shortterm rates. This linkage could rationalize a stronger effect of monetary policy on house
prices in the more recent period (Iacoviello and Neri, forthcoming).
Some evidence on this question is provided in Slide 7, which shows illustrative
initial monthly mortgage payments for a median-priced house for different types of
mortgages.14 The interest rates used in calculating these payments are actual averages for
prime borrowers for the period from 2003 to 2006, as provided by Freddie Mac. A
14

Calculations are for a house price of $225,000 and a 20 percent down payment.

- 15 comparison of the initial monthly payment for a fixed-rate 30-year mortgage and an
ARM shows that the ARM payment is about 16 percent lower, a consequential but not
dramatic difference. The ARM payment is not substantially lower than the fixed-rate
payment because it includes amortization of principal and a spread over the index interest
rate.15 Moreover, less accommodative monetary policy would not have had a substantial
effect on ARM payments. Using the Board’s principal macroeconometric model, staff
simulated the effects on the economy and on mortgage rates of a monetary policy that
followed the original 1993 Taylor rule, taking into account the feedback effects from
tighter policy to the economy.16 Under this scenario, they found that the initial ARM rate
would have been about 0.71 percentage point higher than in the baseline and that the
initial monthly payment for an ARM borrower would have increased by only about $75.
This result does not suggest that moderately tighter monetary policy would have
dissuaded many potential ARM borrowers.
Slide 7 also shows initial monthly payments for some alternative types of
variable-rate mortgages, including interest-only ARMs, long-amortization ARMs,
negative amortization ARMs (in which the initial payment does not even cover interest
costs), and pay-option ARMs (which give the borrower considerable flexibility regarding
the size of monthly payments in the early stages of the contract). These more exotic
mortgages show much more significant reductions in the initial monthly payment than

15

The figures in Slide 7, which are for prime borrowers, also take no account of the fact that subprime
borrowers using ARM products typically faced both higher interest rates and additional fees.
16
The simulation covered the period from 2003 through 2005. The year 2006 was excluded because actual
policy and that prescribed by the 1993 Taylor rule were not significantly different in that year. When the
1993 Taylor rule is assumed to govern monetary policy, the simulated federal funds rate averages 2.6
percent from 2003 to 2005, 70 basis points higher than in the baseline. The increase in the federal funds
rate is less than the difference shown in Slide 4 because of feedback effects working through the economy;
a less accommodative policy rule reduces output and inflation, which in turn limits the increase in rates
implied by the policy rule.

- 16 could be obtained through a standard ARM. Clearly, for lenders and borrowers focused
on minimizing the initial payment, the choice of mortgage type was far more important
than the level of short-term interest rates.
The availability of these alternative mortgage products proved to be quite
important and, as many have recognized, is likely a key explanation of the housing
bubble. Slide 8 shows the percentage of variable-rate mortgages originated with various
exotic features, beginning in 2000. As you can see, the use of these nonstandard features
increased rapidly from early in the decade through 2005 or 2006. Because such features
are presumably not appropriate for many borrowers, Slide 8 is evidence of a protracted
deterioration in mortgage underwriting standards, which was further exacerbated by
practices such as the use of no-documentation loans. The picture that emerges is
consistent with many accounts of the period: At some point, both lenders and borrowers
became convinced that house prices would only go up. Borrowers chose, and were
extended, mortgages that they could not be expected to service in the longer term. They
were provided these loans on the expectation that accumulating home equity would soon
allow refinancing into more sustainable mortgages. For a time, rising house prices
became a self-fulfilling prophecy, but ultimately, further appreciation could not be
sustained and house prices collapsed. This description suggests that regulatory and
supervisory policies, rather than monetary policies, would have been more effective
means of addressing the run-up in house prices. I will return to this point in my
conclusion.
Let me turn now to the international evidence on the link between monetary
policy and house price appreciation. Some cross-country evidence on this link is shown

- 17 in Slide 9. The figure is drawn from a recent study of 20 industrial countries by the
International Monetary Fund (IMF) (Fatás and others, 2009) and replicated by Board
staff. The vertical axis of the figure shows the change in real (inflation-adjusted) house
prices in each country from the fourth quarter of 2001 until the third quarter of 2006, a
period that spans the sharpest period of price appreciation in most countries. Countries
represented by diamonds that are further “north” in Slide 9 had relatively greater house
price appreciation over this period. You can see from the figure that house price
appreciation in the United States, though of course large in absolute terms, was actually
less than that in the majority of countries in the sample.
The horizontal axis of the figure, following the IMF study, shows the degree of
monetary policy ease or tightness in each country, measured by the average deviation of
policy in each country from the prescriptions of a standard version of the Taylor rule over
the corresponding period. Countries shown further to the left in the figure had more
accommodative monetary policies over the period, relative to the predictions of the
Taylor rule. The United States is shown as having a relatively accommodative policy, as
you can see; however, that conclusion is driven in part by the use of current rather than
forecast inflation in the Taylor rule, the point I discussed earlier. Interestingly,
essentially all of these countries had monetary policies easier than that prescribed by the
Taylor rule, as shown by the fact that every country is situated on or to the left of the
vertical axis in the figure.17
17

Note that the figure ascribes different degrees of monetary ease to different countries within the euro
area; although these countries share the common monetary policy of the European Central Bank,
differences across countries in inflation and output gaps imply that the degree of policy accommodation
relative to economic conditions in each country can differ. In particular, holding constant the interest rate
set by the European Central Bank, the Taylor rule will tend to impute easier monetary policies to countries
with strong economies. Of course, all else equal, a strong economy, even if its strength is unrelated to
monetary policy, should experience more robust house prices. Consequently, the relationship shown in

- 18 As Slide 9 shows, the relationship between the stance of monetary policy and
house price appreciation across countries is quite weak. For example, 11 of the 20
countries in the sample had both tighter monetary policies, relative to the standard
Taylor-rule prescriptions, and greater house price appreciation than the United States.
The overall relationship between house prices and monetary policy, shown by the solid
line, has the expected slope (tighter policy is associated with somewhat slower house
price appreciation). However, the relationship is statistically insignificant and
economically weak; moreover, monetary policy differences explain only about 5 percent
of the variability in house price appreciation across countries.
What does explain the variability in house price appreciation across countries? In
previous remarks I have pointed out that capital inflows from emerging markets to
industrial countries can help to explain asset price appreciation and low long-term real
interest rates in the countries receiving the funds--the so-called global savings glut
hypothesis (Bernanke, 2005, 2007). Today is not the appropriate time to revisit that
hypothesis in any detail, but I would like to take a moment to show that accounting for
capital inflows is likely to prove fruitful for explaining cross-country differences. Slide
10, which is analogous to Slide 9, shows the relationship between capital inflows and
house price appreciation for the same set of countries as in the previous slide. Also as in
the previous slide, house price appreciation is shown on the vertical axis of the figure.
The horizontal axis shows the increase in the current account (equivalently, the increase
in capital inflows) for each country, measured as a percentage of GDP. The downward

Slide 9 could potentially overstate the causal relationship between monetary policy and house price
appreciation. For the group of euro-zone countries included in Slide 9, the slope of the relationship
between house prices and monetary policy accommodation is economically more consequential but not
statistically significant (t = -1.55, R2 = 0.23).

- 19 slope of the relationship is as expected--countries in which current accounts worsened
and capital inflows rose (shown in the left half of the figure) had greater house price
appreciation over this period.18 However, in contrast to the previous slide, the
relationship is highly significant, both statistically and economically, and about
31 percent of the variability in house price appreciation across countries is explained.19
This simple relationship requires more interpretation before any strong conclusions about
causality can be drawn; in particular, we need to understand better why some countries
drew stronger capital inflows than others. I will only note here that, as more
accommodative monetary policies generally reduce capital inflows, this relationship
appears to be inconsistent with the existence of a strong link between monetary policy
and house price appreciation.
Conclusions and Policy Implications
My objective today has been to review the evidence on the link between monetary
policy in the early part of the past decade and the rapid rise in house prices that occurred
at roughly the same time. The direct linkages, at least, are weak. Because monetary
policy works with a lag, policymakers’ response to changes in inflation and other
economic variables should depend on whether those changes are expected to be
temporary or longer-lasting. When that point is taken into account, policy during that
period--though certainly accommodative--does not appear to have been inappropriate,
given the state of the economy and policymakers’ medium-term objectives. House prices
began to rise in the late 1990s, and although the most rapid price increases occurred when
short-term interest rates were at their lowest levels, the magnitude of house price gains

18
19

Ahearne and others (2005) obtain similar results.
The slope coefficient of -3.93 is statistically significant at the 1 percent level (t = -2.84, p = 0.0109).

- 20 seems too large to be readily explainable by the stance of monetary policy alone.
Moreover, cross-country evidence shows no significant relationship between monetary
policies and the pace of house price increases.
What policy implications should we draw? I noted earlier that the most important
source of lower initial monthly payments, which allowed more people to enter the
housing market and bid for properties, was not the general level of short-term interest
rates, but the increasing use of more exotic types of mortgages and the associated decline
of underwriting standards. That conclusion suggests that the best response to the housing
bubble would have been regulatory, not monetary. Stronger regulation and supervision
aimed at problems with underwriting practices and lenders’ risk management would have
been a more effective and surgical approach to constraining the housing bubble than a
general increase in interest rates. Moreover, regulators, supervisors, and the private
sector could have more effectively addressed building risk concentrations and inadequate
risk-management practices without necessarily having had to make a judgment about the
sustainability of house price increases.
The Federal Reserve and other agencies did make efforts to address poor
mortgage underwriting practices. In 2005, we worked with other banking regulators to
develop guidance for banks on nontraditional mortgages, notably interest-only and
option-ARM products. In March 2007, we issued interagency guidance on subprime
lending, which was finalized in June. After a series of hearings that began in June 2006,
we used authority granted us under the Truth in Lending Act to issue rules that apply to
all high-cost mortgage lenders, not just banks. However, these efforts came too late or

- 21 were insufficient to stop the decline in underwriting standards and effectively constrain
the housing bubble.
The lesson I take from this experience is not that financial regulation and
supervision are ineffective for controlling emerging risks, but that their execution must be
better and smarter. The Federal Reserve is working not only to improve our ability to
identify and correct problems in financial institutions, but also to move from an
institution-by-institution supervisory approach to one that is attentive to the stability of
the financial system as a whole. Toward that end, we are supplementing reviews of
individual firms with comparative evaluations across firms and with analyses of the
interactions among firms and markets. We have further strengthened our commitment to
consumer protection. And we have strongly advocated financial regulatory reforms, such
as the creation of a systemic risk council, that will reorient the country’s overall
regulatory structure toward a more systemic approach. The crisis has shown us that
indicators such as leverage and liquidity must be evaluated from a systemwide
perspective as well as at the level of individual firms.
Is there any role for monetary policy in addressing bubbles? Economists have
pointed out the practical problems with using monetary policy to pop asset price bubbles,
and many of these were illustrated by the recent episode. Although the house price
bubble appears obvious in retrospect--all bubbles appear obvious in retrospect--in its
earlier stages, economists differed considerably about whether the increase in house
prices was sustainable; or, if it was a bubble, whether the bubble was national or confined
to a few local markets. Monetary policy is also a blunt tool, and interest rate increases in
2003 or 2004 sufficient to constrain the bubble could have seriously weakened the

- 22 economy at just the time when the recovery from the previous recession was becoming
established.
That said, having experienced the damage that asset price bubbles can cause, we
must be especially vigilant in ensuring that the recent experiences are not repeated. All
efforts should be made to strengthen our regulatory system to prevent a recurrence of the
crisis, and to cushion the effects if another crisis occurs. However, if adequate reforms
are not made, or if they are made but prove insufficient to prevent dangerous buildups of
financial risks, we must remain open to using monetary policy as a supplementary tool
for addressing those risks--proceeding cautiously and always keeping in mind the
inherent difficulties of that approach. Clearly, we still have much to learn about how best
to make monetary policy and to meet threats to financial stability in this new era.
Maintaining flexibility and an open mind will be essential for successful policymaking as
we feel our way forward.

- 23 References
Ahearne, Alan, Joseph Gagnon, Jane Haltmaier, Steven Kamin, and others (2002).
“Preventing Deflation: Lessons from Japan’s Experience in the 1990s,”
International Finance Discussion Papers 72. Washington: Board of Governors of
the Federal Reserve System, June.
Ahearne, Alan, John Ammer, Brian Doyle, Linda Kole, and Robert Martin (2005).
“House Prices and Monetary Policy: A Cross-Country Study,” International
Finance Discussion Papers 841. Washington: Board of Governors of the Federal
Reserve System, September.
Bernanke, Ben S. (2005). “The Global Savings Glut and the U.S. Current Account
Deficit,” speech delivered at the Sandridge Lecture, Virginia Association of
Economics, Richmond, Va., March 10,
www.federalreserve.gov/boarddocs/speeches/2005/200503102/default.htm.
Bernanke, Ben S. (2007). “Global Imbalances: Recent Developments and Prospects,” at
the Bundesbank Lecture, Berlin, Germany, September 11,
www.federalreserve.gov/newsevents/speech/bernanke20070911a.htm.
Del Negro, Marco, and Christopher Otrok (2007). “99 Luftballons: Monetary Policy and
the House Price Boom across U.S. States,” Journal of Monetary Economics,
vol. 4, pp. 1962-85.
Dokko, Jane, Brian Doyle, Michael T. Kiley, Jinill Kim, Shane Sherlund, Jae Sim, and
Skander Van den Heuvel (2009). “Monetary Policy and the Housing Bubble,”
Finance and Economics Discussion Series 2009-49. Washington: Board of
Governors of the Federal System, December,
www.federalreserve.gov/pubs/feds/2009/200949/200949abs.html.
Edge, Rochelle M., Michael T. Kiley, and Jean-Philippe Laforte (2008). “The Sources of
Fluctuations in Residential Investment: A View from a Policy-Oriented DSGE
Model of the U.S. Economy,” paper presented at the 2009 American Economic
Association annual meeting, held January 3-5,
www.aeaweb.org/assa/2009/retrieve.php?pdfid=372.
Eggertsson, Gauti, and Michael Woodford (2003). “The Zero Interest-Rate Bound and
Optimal Monetary Policy,” Brookings Papers on Economic Activity, vol. 1,
pp. 139-211.
Fatás, Antonio, Prakash Kannan, Pau Rabanal, and Alasdair Scott (2009). “Lessons for
Monetary Policy from Asset Price Fluctuations,” in World Economic Outlook
(Fall), chapter 3. Washington: International Monetary Fund,
www.imf.org/external/pubs/ft/weo/2009/02/pdf/c3.pdf.

- 24 Fuhrer, Jeffrey C. and Brian F. Madigan, 1997. “Monetary Policy When Interest Rates
Are Bounded at Zero,” The Review of Economics and Statistics, vol. 79
(November), pp 573-85.
Iacoviello, Matteo, and Stefano Neri (forthcoming). “Housing Market Spillovers:
Evidence from an Estimated DSGE Model,” American Economic Journals:
Macroeconomics.
Jarociński, Marek, and Frank R. Smets (2008). “House Prices and the Stance of Monetary
Policy,” Federal Reserve Bank of St. Louis, Review, vol. 90 (July/August),
pp. 339-65,
www.research.stlouisfed.org/publications/review/08/07/Jarocinski.pdf.
Kohn, Donald L. (2007). “John Taylor Rules,” speech delivered at “Conference on John
Taylor’s Contributions to Monetary Theory and Policy,” Federal Reserve Bank of
Dallas, Dallas, Tex., October 12,
www.federalreserve.gov/newsevents/speech/kohn20071012a.htm.
Orphanides, Athanasios, and Volcker Wieland (2008). “Economic Projections and Rules
of Thumb for Monetary Policy,” Federal Reserve Bank of St. Louis, Review,
vol. 90 (July/August), pp. 307-24.
Reifschneider, David, and John C. Williams (2000). “Three Lessons for Monetary Policy
in a Low Inflation Era,” Federal Reserve Bank of Boston Conference Series,
pp. 936-78. Boston: Federal Reserve Bank of Boston.
Shiller, Robert J. (2007). “Understanding Recent Trends in House Prices and
Homeownership,” in Proceedings of the symposium “Housing, Housing Finance,
and Monetary Policy.” Kansas City: Federal Reserve Bank of Kansas City,
pp. 89-123, www.kansascityfed.org/publicat/sympos/2007/PDF/Shiller_0415.pdf.
Taylor, John B. (1993). “Discretion versus Policy Rules in Practice,” Carnegie-Rochester
Conference Series on Public Policy, vol. 39 (December), pp. 195-214.
Taylor, John B. (1999a). “An Historical Analysis of Monetary Policy Rules,” in John B.
Taylor, ed., Monetary Policy Rules. Chicago: University of Chicago Press.
Taylor, John B., ed. (1999b). Monetary Policy Rules. Chicago: University of Chicago
Press.
Taylor, John B. (2007). “Housing and Monetary Policy,” NBER Working Paper Series
13682. Cambridge, Mass.: National Bureau of Economic Research, December,
www.nber.org/papers/w13682.pdf.
.
Woodford, Michael (2007). “The Case for Forecast Targeting as a Monetary Policy
Strategy,” Journal of Economic Perspectives, vol. 21 (4), pp. 3-24.

Monetary Policy and the
Housing Bubble
Ben SS. Bernanke
Chairman, Board of Governors
of the Federal Reserve System

The Target Federal Funds Rate
9
8
7
6
5
4
3
2
1

2009Q1

2008Q1

2007Q1

2006Q1

2005Q1

2004Q1

2003Q1

2002Q1

2001Q1

2000Q1

0

T
Target
tR
Rate
t

Source: Federal Reserve Board.

1

Evaluating the Tightness or Ease
off Monetary Policy
li
General form of the Taylor
y rule:

it  2   t  a( t   )  b( yt  y )
*

*
t

where
• it is the prescribed value of the policy interest rate in a
given
i
period
i d t;
t
•  t   * is the deviation of the actual inflation rate t
from its target
g  * in p
period t;;
• yt  yt* , the “output gap,” is the deviation of actual real
output yt from potential output yt* in period t; and
• a and b are positive numbers.
2

The Target Federal Funds Rate and the
Taylor (1993) Rule Prescriptions
9

8

7

6

5

4

3

2

1

Target Rate

Taylor Rule (output gap and headline CPI inflation as currently measured)

Source: Federal Reserve Board, Bureau of Labor Statistics, Bureau of Economic Analysis, and Federal Reserve staff calculations.

2009
9Q1

2008
8Q1

2007
7Q1

2006
6Q1

2005
5Q1

2004
4Q1

2003
3Q1

2002
2Q1

2001
1Q1

2000
0Q1

0

3

The Target Rate and the Taylor Rule Prescriptions
Using Real‐Time Inflation Forecasts

9
8
7
6
5
4
3
2
1

2009Q1

2008Q1

2007Q1

2006Q1

2005Q1

2004Q1

2003Q1

2002Q1

2001Q1

2000Q1

0

Target Rate
Taylor Rule (output gap and headline CPI inflation as currently measured)
Taylor Rule (output gap and forecast of PCE inflation as measured in real time)
Source: Federal Reserve Board, Bureau of Labor Statistics, Bureau of Economic Analysis, and Federal Reserve staff calculations.

4

Rate of Increase in House Prices
1978:Q1‐2009:Q3

Fo
our-quarter c
change (perc
cent)

20

10

0

-10

-20
20

-30
1980

1985

Note: Shaded areas refer to NBER recessions.
Source: FirstAmerican LoanPerformance.

1990

1995

2000

2005

5

Conditional Forecasts for the
Federal
d l Funds
d Rate and
d House Prices
i
8

Federal Funds Rate

Real House Prices

60

50

6

40
L o g p o in ts

Pe rce n t

4

2

30

20
0

10

-2

0
00

01

02

03

04

05

06

07

08

00

01

02

03

04

05

06

07

08

Note: Shaded areas denote values within 2 standard deviations of the conditional forecast of each variable.
Source: Federal Reserve Board, Bureau of Economic Analysis, FirstAmerican LoanPerformance, and Federal
Reserve staff calculations.

6

Alternative Mortgage Instruments and
A
Associated
i d Initial
I i i l Monthly
M hl Payments
P
Mortgage Product

Initial
Monthly
Payment

Fixed‐rate mortgage (FRM)

$1,079.19

100.0

Adjustable‐rate mortgage (ARM)

903.50

83.7

Interest‐only/ARM

663.00

61.4

40‐year amortization (ARM)

799.98

74.1

Negative amortization ARM

150.00

13.9

<150.00

<13.9

Pay‐option ARM

Payment as a
Percentage of
FRM Payment

Note: Interest rates used in these calculations were 6.00 percent for FRMs and 4.42 percent for standard
ARMs. For purposes off the
h calculations,
l l i
we assume a house
h
price
i off $225,000
$22 000 and
d a 20 percent down
d
payment, and that the borrower qualifies for a prime product.
Source: Interest rates for these calculations are from Freddie Mac and are for the period from 2003
through 2006.

7

Nontraditional Mortgage Features
(P
(Percent
t off ARM originations)
i i ti )
Interest Only
l
Subprime

2000
2001
2002
2003
2004
2005
2006

0
0
2
5
18
21
16

Extended
Negative
Pay‐
Amortization
i i
Amortization
i i Option
i

Alt‐A Subprime

3
8
37
48
51
48
51

0
0
0
0
0
13
33

Alt‐A

Alt‐A

Alt‐A

0
0
0
0
0
0
2

‐‐‐
‐‐‐
‐‐‐
19
40
46
55

‐‐‐
‐‐‐
‐‐‐
11
25
38
38

Source: Calculations based on data from First American LoanPerformance.

8

Change in real house pricess
(200
01Q4 ‐200
06Q3)

Monetary Policy and House Prices
i th
in
the Ad
Advanced
d EEconomies
i

‐4.5

80
New Zealand

Spain
IIreland
l d
R² = 0.05
T‐statistic =‐0.97

Greece

France
60
Denmark
United Kingdom
Belgium
Sweden
C
Canada
d
40
Australia Finland
Italy
Norway
United States
20
Netherlands
Switzerland

‐4

‐3.5

‐3

‐2.5

‐2

Austria
‐1.5
‐1

0
‐0.5
0
Germany
‐20
Japan

0.5

‐40
40

Average Taylor rule residuals (2002Q1‐2006Q3)
Source: International Monetary Fund.

9

Current Accounts and House Prices
in the Advanced Economies
80

Chaange in real house pricces (2001Q
Q4 ‐2006Q3
3)

Spain

New Zealand

Ireland

France
60
United Kingdom Belgium

Denmark
Sweden

Australia

Finland

Italy

Canada

40

Norway

United States

Greece

20

R² = 0.31
T
T‐statistic
i i = ‐2.84
2 84

Netherlands
Switzerland

0

‐6

‐4

‐2

0
‐20

2

Austria 4

6
Germany

8

Japan

‐40

Change in Current Account as Percent of GDP (2001Q4‐2006Q3)
Source: International Monetary Fund, Haver Analytics, and Federal Reserve staff calculations.

10