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Authorized for public release by the FOMC Secretariat on 04/15/2016
	

October 12, 2010

Historically-Determined Inflation in the Context of

Price Level and Inflation Targeting Regimes

Ken Beauchemin and Mark Schweitzer
I.

Introduction

This memo is provided to the Committee to help gauge the inflation environment that is
likely to surround state-contingent price level objective policy, such as the one outlined by
President Charles Evans in his September 14, 2010 memo. It also compares that environment
with one generated by an inflation targeting regime. We make no attempt to analyze the impact
of the policy on economic outcomes and welfare. Instead, we characterize the range of probable
inflation rates that would prevail over the medium run under the current stance of monetary
policy and suggest that these projections might provide reasonable “lower bound” estimates for a
future targeting regime if that policy regime does not significantly alter the existing inflation
outlook. We use a standard reduce-form Bayesian vector autoregression to produce the range
and likelihoods of inflation outcomes.
Our main conclusions are as follows:
•	 A price level target based on 2% inflation results in an inflation rate between 2.8% and

3.5% when the target is attained, and a rate one year later between 2.5% and 4.8%. 1

•	 An inflation target of 2% annually results in an inflation rate of between 2.1% and 2.5%
when the target is reached, and between 1.8% and 4.0% one year later.
•	 Potential advocates of targets for either a price level or an inflation rate should be aware of
the size and range of possible inflation rates that are likely to accompany these policies.

II.

The BVAR Projection

To produce our forecast, we use a medium-scale (15-variable) Bayesian vector
autoregressive (BVAR) model. Our principle variable of interest is the core personal
consumption expenditures (PCE) price index, but naturally the model produces forecasts for all
other variables in the model that help predict inflation. We choose a model in the BVAR class
for three principle reasons. First, BVARs allow one not only to predict the most likely forecast
path for the variables, but also easily enable one to construct a complete probabilistic statement
of the uncertainty surrounding that forecast. Second, models of this type have recently been
shown to outperform a number of popular alternatives in terms of forecast accuracy. 2 Finally,

1

All inflation rates in this memo are expressed as four-quarter percent changes.

2

See Banbura, Giannone, and Reichlin (2010) and Koop (2010).

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October 12, 2010

the results of these models are easily reproduced. The specific features of our model are
described in the Explanatory Notes at the conclusion of this memo.
The likely forecast path of a variable and the likelihoods of the alternatives are described
by a predictive density. It is as natural instrument to evaluate the likelihood of alternative
outcomes for targeting regimes whether expressed in price levels or inflation rates, provided that
inflation and inflation expectations dynamics are not appreciably altered by the change in policy
regime. Of course, we recognize that the principle advantage of explicit target policies is
precisely to alter inflation expectations by exploiting some capacity for a central bank to commit
itself to a future course of state-contingent actions. It is likely that today’s inflation dynamics
already reflect some degree of acceptance of inflation targeting given the Committee’s
communications over the last few years, but a price level target would be largely unanticipated.
In this regard, the comparisons can be understood as a “worst-case” scenario in which the policy
fails in its principle advantage, and historical inflationary forces dominate.
The BVAR forecast runs from the third quarter of 2010 through the fourth quarter of
2020. 3 Figure 1 shows the forecast for core PCE inflation along with the fan chart implied by the
predictive density at each date; the fan chart is rendered with 10th percentile increments so that
core PCE inflation falls within the entire shaded region with 90% probability. After falling for
the first two quarters of the forecast period, core PCE inflation (year-on-year basis) gradually
returns to historical trend values. Figure 2 superimposes the BVAR forecast on the Tealbook’s
September forecast along with the 70% probability bands from each. In contrast to the BVAR
forecast, core PCE inflation expected by the Tealbook continues to fall though 2012 leaving it
below the Committee’s objectives for the duration of the forecast (which ends in 2014). The
BVAR forecast is more sanguine in that core PCE inflation returns to a mandate consistent 1.7­
2.0% range by mid-2012. Nevertheless, the Tealbook forecast falls comfortably in the BVAR
70% probability bands implying that the two forecasts are not radically divergent. 4
Figure 2 shows the core PCE price levels implied by the BVAR inflation forecast versus
two price level targets. The upper one corresponds to a constant 3% inflation rate beginning in
the fourth quarter of 2007 and the other to a steady 2% inflation beginning at the same time.
Even though the BVAR expected inflation rate forecast looks acceptable from a policy
perspective, it implies an expected path for the price level that remains below the 2% target level
for the next ten years. This reflects the large amount of inflation persistence evident in the
historical data. In terms of possible outcomes, roughly 50% of price paths breach the 2% target
level in the next ten years with the other half falling short, and roughly one-third of outcomes

3

Observations for third-quarter high-frequency financial variables were imposed directly on the forecast.

4

The wider probability bands of the BVAR forecast implies more forecast uncertainty when compared to the
Tealbook. This is due to a fundamental difference in methods. In addition to stochastic variation in the economic
environment that cannot be captured by the model, Bayesian techniques allow for uncertainty in the parameters of
the model itself.

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attain the 3% target level. In what follows, we confine the discussion to the 2% path, since the
3% path appears too strenuous a target in the context of the BVAR forecast.

III. Price Level/Inflation Comparisons
To evaluate a state contingent, price level targeting regime, it is useful to get an idea of the
inflation rates that can be expected when the predetermined price level path or inflation target is
breached. Ideally, a forecasting model that clearly articulates the structure of the economy
including the formation of inflation expectation and the policy regime would be applied to
answer these questions; however the perfect-foresight general-equilibrium models available to us
result in unrealistically quick movements in inflation. In the strictest sense, using the BVAR
estimates shown here assumes that a new policy regime would not alter the predictive densities.
Nevertheless, the BVAR forecasts can be informative, especially because the policy is designed
to guide inflation expectations, and hence actual inflation, higher. Since the model does not
capture these forces, our inflation forecast, at least in the near-to-medium term, is likely to be
biased downward.
Figure 4a shows the predictive density of year-on-year core PCE inflation in the fourth
quarter of 2012 conditional on the 2% price level target having been attained on or before that
date. In these circumstances, the median forecast is 3.0%, and inflation falls between 2.8% to
3.5% with 70% probability. This compares to the unconditional point forecast of 1.9%. Since
evidence suggests that inflation displays considerable persistence, it is worthwhile to ask what
becomes of inflation on these same paths, but one year later. Figure 4b indicates that the median
inflation rate rises to 3.6% with the 70% probability band between 2.4% and 4.8%. We ran the
same exercise using later dates for price level target attainment; the pattern is quite consistent
although the point estimates are all higher. 5
We also considered, for comparison purposes, BVAR estimates for inflation rates when an
inflation target (not a price level target) of 2% is breached. Figure 5a shows the predictive
density of core PCE inflation for all paths that attain a 2% rate by the end of 2012; the median
inflation rate is 2.2% and is framed by a narrow probability band one-half of a percentage point
wide. Although the federal funds rate remains exceptionally low on the median path, Figure 5b
shows that the median inflation rate one year out rises to just 2.8%—roughly one percentage
point lower than those produced with a price-level target.

IV. Conclusion
We have proposed a simple method to gauge the inflation implications of a state-contingent
price level and inflation targets using a standard reduce-form Bayesian vector auto regression.
5

We excluded this figures from the memo for brevity, but they are available on request.

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Although it cannot capture the novel inflation dynamics resulting from a switch in the monetary
policy regime, we think that it provides a useful lower bound on expected near- and mediumterm inflation rates. Our results indicate that a price level target defined by the constant 2%
inflation path is likely to produce a substantial overshooting of 2% inflation, with the median
forecast reaching at rate of 3% at the crossing and 3.6% one year later. Overshooting also occurs
in this environment when a 2% inflation rate target is met, but the levels of inflation are notably
lower. Of course, overshooting is a necessary consequence of the state-contingent price level
targeting policy. We hope that our results provide a fruitful first step at gauging the amount of
overshooting that can be expected and the level of uncertainty that must be tolerated.

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Explanatory Notes
A Medium Scale BVAR Model
We produced the point forecast and predictive densities using a fifteen variable, reducedform Bayesian vector autoregression (BVAR) estimated at the quarterly frequency. The model
includes three of the four variables that are submitted to the Federal Open Market Committee
four times a year: real GDP, the unemployment rate, and the core personal consumption
expenditures (PCE) price index. Labor productivity, labor compensation (which together imply
unit labor costs), and the federal funds rate are included to help capture the essence of a newKeynesian inflationary process. The model also includes yields on 10-year U.S. Treasuries and
AAA rated corporate debt to provide information on term and credit spreads. The S&P 500
equity price index and the S&P500 dividend yield round out the list of financial variables. The
remaining variables are personal consumption expenditures, government purchases, the producer
price index for industrial materials, and a trade-weighted nominal exchange rate.
Each variable enters the system in log-level form and there are four lags of each variable in
each of the 15 equations (in addition to a constant). Bayesian shrinkage is used to reduce
degradation of forecast performance due to overfitting. We use a normal inverted Wishart prior
that retains the basic properties of the traditional Minnesota prior: coefficients on the first own
lags are shrunk toward one and all others to zero and recent lags are more important than distant
ones so that the prior coefficient variances are smaller for distant lags. We also use the “inexact
differencing” prior that shrinks the sum of the own lag coefficients toward one. 6 We set the
hyperparameters that control the overall tightness of each set of priors to optimize forecast
performance during the 2009Q3–2010Q2 period. The model is estimated using data from the
1960Q1–2010Q2 period. Finally, the predictive densities are computed with 2000 draws from
the posterior distribution of parameters and 2000 histories of innovations for a total of 40,000
separate projections.

REFERENCES
Banbura, Marta, Domenico Giannone, and Lucrezia Reichlin (2010). “Large Bayesian
Vector Auto Regressions,” Journal of Applied Econometrics, 25, 71-92.

6

The prior distributions are set forth in Sims and Zha (1998) and explained in the context of a complete forecasting
exercise in Robertson and Tallman (1999). We follow Banbura, Giannone, and Reichlin (2010) in our
implementation of the priors.

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Koop, Gary (2010). “Forecasting with Medium and Large Bayesian VARs,” University of
Strathclyde working paper.
Robertson, John C. and Ellis W. Tallman (1999). “Vector Autoregressions: Forecasting and
Reality,” Federal Reserve Bank of Atlanta Economic Review, (Q1), 4-18.
Sims, Christopher A. and Tao Zha (1998). “Bayesian Methods for Dynamic Multivariate
Models,” International Economic Review, 39, 949-68.

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Figure 1: BVAR Estimated Inflation Fan Chart


Figure 2: Greenbook Forecast Range Similar to BVAR

Percent change (Q4/Q4)
Actual
BVAR projection
BVAR 70% CI
8
GB September
GB 70% CI
2% inflation
6

10

4

2

0

-2

-4
2000

2002

2004

2006

2008

2010

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2012

2014

2016

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Figure 3: Price Level Targets Applied to BVAR Predictions


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Figure 4a: Core Inflation Rates at Breaching:

Cases which Breach a 2% Price Level Target Path by 2012

8.0

Percent distribution

Dark blue region = 70% area

7.0
6.0
5.0
4.0
3.0
2.0
1.0

3.0%
0.0
2.0

2.4

2.8

3.1

3.5

3.9

4.3

4.6

5.0

5.4

Core PCE (%)

Figure 4b: Core Inflation Rates One Year Later:
Cases which Breach a 2% Price Level Target Path by 2012
5.0

Percent distribution

Dark blue region = 70% area

4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5

3.6%

0.0
-0.2

1.1

2.3

3.6

Core PCE (%)

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4.8

6.1

7.3

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Figure 5a: Core Inflation Rates at Breaching:

Cases which Breach a 2% Annual Inflation Target by 2012


4.5

Percent distribution

Dark blue region = 70% area

4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5

2.2%
0.0
2.0

2.2

2.4

2.6

2.8

2.9

3.1

Core PCE (%)

Figure 5b: Core Inflation Rates One Year Later:
Cases which Breach a 2% Annual Inflation Target by 2012

3.0

Percent distribution

Dark blue region = 70% area

2.5

2.0

1.5

1.0

0.5

2.8%
0.0
-1.3

-0.4

0.6

1.5

2.5

3.4

Core PCE (%)

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4.3

5.3

6.2