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O PTIMAL M ONETARY P OLICY FOR
THE M ASSES
James Bullard (FRB of St. Louis)
Riccardo DiCecio (FRB of St. Louis)

University of Birmingham
Birmingham, United Kingdom
Aug. 9, 2018
Any opinions expressed here are our own and do not necessarily reflect those of the FOMC.

I NTRODUCTION

E NVIRONMENT

P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

Introduction

I NEQUALITY

P OLICY

C ONCLUSIONS

I NTRODUCTION

E NVIRONMENT

P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

P OLICY

C ONCLUSIONS

I NEQUALITY AND MONETARY POLICY

Interest in income, financial wealth, and consumption inequality
has increased in the last decade.
Can monetary policy be conducted in a way that benefits all
households even in a world of substantial heterogeneity?
The answer in this paper is “yes.”
Material has been posted online and previously presented at the
Norges Bank, the St. Louis Fed, the Dallas Fed, the Texas
Monetary Conference, and the Barcelona Workshop on Monetary
Policy and Central Banking.

I NTRODUCTION

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C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

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C ONCLUSIONS

S OME RECENT LITERATURE
Kaplan, Moll, and Violante (AER, 2018):
NK macro with heterogeneous households (“HANK”); reasonable
Gini coefficients.
The monetary policy transmission mechanism is substantially
altered relative to standard model.

Bhandari, Evans, Golosov, and Sargent (Working paper, NYU,
2018):
Incomplete markets, nominal friction, heterogeneous households
(“HAIM”); reasonable Gini coefficients.
Optimal monetary-fiscal policy (Ramsey) substantially altered
relative to standard model.
See A. Bhandari, D. Evans, M. Golosov, and T. Sargent, "Inequality,
Business Cycles, and Monetary-Fiscal Policy," Working Paper, New
York University, June 6, 2018, available at
http://www.tomsargent.com/research/begs2.pdf.

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S OME RECENT LITERATURE

Bullard and DiCecio (Working paper, St. Louis Fed, 2018):
Incomplete markets, nominal friction, heterogeneous households
(“HAIM”); reasonable Gini coefficients.
Optimal monetary policy repairs the distortion caused by the
friction for all households.

See also the conference on “Monetary Policy and the Distribution
of Income and Wealth,” held at the St. Louis Fed on Sept. 11–12,
2015. Program available at https://research.stlouisfed.org/
conferences/monetary_policy_conf/program.

I NTRODUCTION

E NVIRONMENT

P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

W EALTH , INCOME , AND

I NEQUALITY

P OLICY

C ONCLUSIONS

CONSUMPTION INEQUALITY

There is a lot of financial wealth, income, and consumption
inequality in this stylized model.
The role of credit markets, if they work correctly, is to reallocate
uneven income across the life-cycle into perfectly equal
consumption shares by cohort, appropriately scaled by life cycle
productivity.
The model equilibrium generates realistic Gini coefficients.

I NTRODUCTION

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C HARACTERIZING THE E QUILIBRIUM

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C ONCLUSIONS

O PTIMAL MONETARY POLICY

The role of monetary policy in this model is to make sure credit
markets are working correctly (i.e., complete).
Practically speaking, this optimal monetary policy looks like
“nominal GDP targeting.”
This result continues to hold even when there is “massive”
heterogeneity—enough heterogeneity to approximate income,
financial wealth, and consumption inequality in the U.S.
Hence, the main result is that NGDP targeting constitutes “optimal
monetary policy for the masses” in this environment.

I NTRODUCTION

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P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

Environment

I NEQUALITY

P OLICY

C ONCLUSIONS

I NTRODUCTION

E NVIRONMENT

P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

P OLICY

C ONCLUSIONS

L IFE - CYCLE MODELS
General-equilibrium life-cycle economy.
Each period, a new cohort of households enters the economy,
makes economic decisions over the next 241 periods, then exits the
economy. The model is therefore “quarterly.”
Households have log preferences defined over consumption and
leisure.
Households are assigned a personal productivity profile when they
enter the model.
The profile is symmetric—it begins low, rises and peaks exactly in
the middle of life, then declines back to the low level. There will be
many of these, as discussed below.
Productivity units determine the value of an hour worked in a
competitive labor market.
There is no population growth in this version.

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C ONCLUSIONS

H OUSEHOLD CREDIT

The overlapping-generations structure creates a large private
credit market essential to good macroeconomic performance.
Relatively young households want to borrow to move
consumption forward in the life cycle, while middle-aged
households wish to save for retirement. So households in the
middle of life lend to the relatively young.
The key variable is therefore privately issued household debt.
Household debt outstanding in the U.S. is on the order of GDP,
around $20 trillion.
As practical motivation, think of privately issued debt =
“mortgage-backed securities.”

I NTRODUCTION

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C HARACTERIZING THE E QUILIBRIUM

N ON - STATE CONTINGENT

I NEQUALITY

P OLICY

C ONCLUSIONS

NOMINAL CONTRACTING

There is a friction in the credit market: Non-state contingent
nominal contracting (NSCNC).
NSCNC: Loans are dispersed and repaid in the unit of account—that
is, in nominal terms—and are not contingent on income realizations.
There are two aspects to this friction:
The non-state contingent aspect means that real resources are
misallocated via this friction.
The nominal aspect means that the monetary authority may be able
to fix the distortion to the equilibrium.

I NTRODUCTION

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C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

P OLICY

C ONCLUSIONS

L INEAR PRODUCTION TECHNOLOGY

Output is produced using a technology that is linear in the labor
input.
In the equilibrium we study, the labor input (hours worked) will
be constant.
The level of technology (aka “aggregate productivity”) grows at
a stochastic rate.
The technology growth rate is bounded so that the ZLB is avoided.

The real wage grows at the same stochastic rate as aggregate
productivity.

I NTRODUCTION

E NVIRONMENT

T IMING

P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

P OLICY

C ONCLUSIONS

PROTOCOL

At the beginning of every date, nature moves first and chooses
the growth rate of aggregate productivity, which therefore
implies a value for the real wage.
The policymaker moves next and chooses a value for the price
level.
Households then decide how much to work, consume, and save.

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C ONCLUSIONS

N OMINAL INTEREST RATE DETERMINATION

Households meet in a competitive market for nominally
denominated, non-state contingent loans.
The non-state contingent nominal interest rate, “the contract
rate,” that clears this market is given by expected nominal GDP
growth.
In the equilibrium we study, this expectation is the same for all
households, even those born at different dates or with different
levels of personal productivity.

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C HARACTERIZING THE E QUILIBRIUM

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C ONCLUSIONS

T HE EQUILIBRIUM MONETARY POLICY CREATES
The monetary policymaker follows a nominal GDP targeting
rule that delivers complete-markets consumption allocations.1
That is, low inflation in response to a high realization of the
aggregate productivity growth rate, and vice versa.

Given this policy rule, households consume equal amounts of
available production, given their productivity, “equity share
contracting,” which is optimal under homothetic preferences.
This means that any two households that share the same
personal productivity profile will consume the same amount at
each date.
The nominal GDP targeting rule perfectly insures the household
against future shocks to income.
Income, consumption, and asset holdings fluctuate from period
to period but in proportion to the value of the real wage.

1 Similar

to Sheedy (BPEA, 2014) and Koenig (IJCB, 2013):

I NTRODUCTION

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C HARACTERIZING THE E QUILIBRIUM

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P OLICY

C ONCLUSIONS

T HE W ICKSELLIAN NATURAL REAL RATE OF INTEREST

The equilibrium we study has the following property:
The real interest rate is exactly equal to the output growth rate at every
date, even in the stochastic economy.

One could think of this as “the Wicksellian natural real rate of
interest.”
This in turn creates a set of easy-to-understand baseline results
for this stylized economy.

I NTRODUCTION

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P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

Life-Cycle Productivity

P OLICY

C ONCLUSIONS

I NTRODUCTION

E NVIRONMENT

P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

P OLICY

C ONCLUSIONS

L IFE - CYCLE PRODUCTIVITY PROFILES

Households entering the economy draw a scaling factor and
receive a life-cycle productivity profile, which is a scaled version
of the baseline profile.
Life-cycle productivity profiles, once assigned, are deterministic.
This process is a stand-in for the human capital development
that takes place before age 20 in actual economies, including
schooling, parenting, and any pre-age 20 job experience.
Huggett, Ventura, and Yaron (AER, 2011) argue that differences
in human capital initial conditions are more important than
differences in shocks for life-cycle earnings.

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C ONCLUSIONS

B ASELINE LIFE - CYCLE PRODUCTIVITY
3.5
3
2.5
2
1.5
0

60

120

180

240

quarters
F IGURE : Baseline endowment profile. The profile is symmetric and peaks in
the middle period of the life cycle.

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T HE MASS

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I NEQUALITY

OF LIFE - CYCLE PRODUCTIVITY

F IGURE : The mass of endowment profiles.

P OLICY

C ONCLUSIONS

I NTRODUCTION

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P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

P OLICY

Characterizing the Equilibrium

C ONCLUSIONS

I NTRODUCTION

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P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

P OLICY

C ONCLUSIONS

L ABOR / LEISURE
1
0.8
0.6
0.4
0.2
0

0

60

120

180

240

quarters
F IGURE : Cross section: Leisure decisions by age (green), labor supply by age
(blue), and fraction of work time in U.S. data, 19% (red). The labor/leisure
choices depend on age only. High-income households work the same hours
as low-income households at each age.

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C ONCLUSIONS

L ABOR INCOME MASS

F IGURE : Cross section: Labor income profiles. Personal productivity peaks at
the middle of the life cycle, and households work more at that time as well,
making income even more concentrated in the peak earning years.

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C ONCLUSIONS

C ONSUMPTION MASS

F IGURE : Cross section: Consumption mass (red) and labor income mass
(blue) along the complete-markets balanced growth path. Under optimal
monetary policy, the private credit market reallocates uneven labor income
into perfectly equal consumption for each productivity profile. The
consumption Gini is 31.8%, similar to values calculated from U.S. data.

I NTRODUCTION

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N ET

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C HARACTERIZING THE E QUILIBRIUM

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P OLICY

C ONCLUSIONS

ASSET HOLDING MASS

F IGURE : Cross section: Net asset holding mass. Borrowing, the negative
values to the left, peaks at stage 60 of the life cycle (age ~35), while positive
assets peak at stage 180 of life (age ~65). The financial wealth Gini is 72.7%,
similar to values calculated in U.S. data.

I NTRODUCTION

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P RODUCTIVITY

T HREE NOTIONS

C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

OF INCOME

Three notions of income:
1
2
3

Labor income (Y1 ).
Labor income plus non-negative capital income (Y2 ).
The non-negative component of total income (Y3 ).

Gini coefficients of the various income distributions:
GY1 = 56.2%, GY2 = 51.6%, GY3 = 59.6%.

P OLICY

C ONCLUSIONS

I NTRODUCTION

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P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

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P OLICY

L ABOR INCOME + NON - NEGATIVE CAPITAL INCOME

F IGURE : Cross section: Profiles of labor income and non-negative capital
income.

C ONCLUSIONS

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P OLICY

N ON - NEGATIVE TOTAL INCOME

F IGURE : Cross section: Profiles of non-negative total income.

C ONCLUSIONS

I NTRODUCTION

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P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

Inequality

I NEQUALITY

P OLICY

C ONCLUSIONS

I NTRODUCTION

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C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

P OLICY

C ONCLUSIONS

D ATA ON INEQUALITY IN THE U.S.

Consumption (Heathcote, Perri, and Violante, RED, 2010):
GC,U.S. = 32%.
Income (CBO, 2016): pre-taxes/transfers GY,U.S. = 51%;
post-taxes/transfers GY,U.S. = 43%.
Financial wealth (Davies, Sandström, Shorrocks, and Wolff, EJ,
2011): GW,U.S. = 80%.

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C ONCLUSIONS

I NEQUALITY IN THE MODEL

Financial wealth is defined as the non-negative part of net assets.
Model
GW = 72.7% > GY2 = 51.6% > GC = 31.8%,
versus U.S. data
GW,U.S. = 80% > GY,U.S. = 51% > GC,U.S. = 32%.

I NTRODUCTION

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C HARACTERIZING THE E QUILIBRIUM

Policy

I NEQUALITY

P OLICY

C ONCLUSIONS

I NTRODUCTION

E NVIRONMENT

P RODUCTIVITY

C HARACTERIZING THE E QUILIBRIUM

I NTERPRETING MONETARY

I NEQUALITY

P OLICY

POLICY

The nominal GDP targeting rule characterizes policy by
“counter-cyclical price level” movements.
But the policy can also be interpreted more conventionally in
interest rate terms.
Nominal interest rates are determined in a private market,
understanding policy ...
And policy is made understanding nominal interest rate
determination ...
Nominal interest rate policy is a fixed point of this process.

C ONCLUSIONS

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C ONCLUSIONS

P OLICY CHARACTERIZATION

The nominal rate is determined one period in advance as the
expected rate of nominal GDP growth.
Wicksellian natural real rate = aggregate productivity growth
rate.
The nominal rate is always ratified ex post by the policymaker.
This makes the real rate = aggregate productivity growth rate =
Wicksellian natural real rate of interest.
“Just like the simple NK model.”

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P RODUCTIVITY

N OMINAL GDP

C HARACTERIZING THE E QUILIBRIUM

I NEQUALITY

P OLICY

C ONCLUSIONS

TARGETING

How can we interpret these results as NGDP targeting?
No persistence in productivity growth: The expected rate of NGDP
growth never changes, and the economy never deviates from the
NGDP path. “Perfect NGDP targeting.”
Persistence in productivity growth: The expected rate of NGDP
growth fluctuates persistently with the shock, and it takes longer to
return to the balanced growth NGDP path.
Nominal and real rates fall in a recession.

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E FFECTS

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C ONCLUSIONS

OF A SHOCK
1.06
1.02
1.04
1
1.02
0

5

10

0

quarters

5

10

quarters

1.4

1.06
1.04

1.2

1.02
1
0

5

quarters

10

0

5

10

quarters

F IGURE : Monetary policy responds to a decrease in aggregate productivity
growth by increasing the inflation rate in the period of the shock.
Subsequently, inflation converges to its BGP value from below. The nominal
interest rate drops in the period after the shock.

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Conclusions

I NEQUALITY

P OLICY

C ONCLUSIONS

I NTRODUCTION

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S UMMARY
This paper attributes observed levels of U.S. inequality to
life-cycle effects in conjunction with heterogeneous life-cycle
productivity profiles.
All households in this model, regardless of their assigned
life-cycle productivity profile, face a problem of smoothing
life-cycle consumption in a world with a credit market friction,
“non-state contingent nominal contracting.”
The monetary authority can remove this impediment to life-cycle
consumption smoothing for all households: “optimal monetary
policy for the masses.”
Does monetary policy affect inequality? Yes, it improves
consumption allocations.