View original document

The full text on this page is automatically extracted from the file linked above and may contain errors and inconsistencies.

C LASSIC P OLICY B ENCHMARKS FOR
E CONOMIES WITH S UBSTANTIAL
I NEQUALITY
James Bullard, Federal Reserve Bank of St. Louis
Riccardo DiCecio, Federal Reserve Bank of St. Louis

Fall 2021 Institute Research Conference
Opportunity & Inclusive Growth Institute
Federal Reserve Bank of Minneapolis
Oct. 15, 2021
Any opinions expressed here are our own and do not necessarily reflect those of the FOMC.

1

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

Introduction

2

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

L ARGE - SCALE HETEROGENEOUS - AGENT DSGE

Increasing interest in large-scale heterogeneous-agent DSGE
models.
Realistic degrees of inequality—approaching observed Gini
coefficients.
What is the role of monetary policy in such a model?
Answer in this paper: The role of monetary policy is unchanged.

3

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

O UTLINE OF THE ARGUMENT
We construct a heterogeneous-agent economy featuring:
Three aggregate shocks: (1) total factor productivity, (2) labor
supply and (3) aggregate demand.
Both permanent and temporary idiosyncratic risk at the household
level.
A simple and symmetric structure.
Income, wealth and consumption inequality on the same scale as in
observed economies.

We include four policymaking authorities: (1) monetary, (2)
fiscal, (3) labor market and (4) education.
We describe a competitive equilibrium in which the four
policymakers act in concert to attain a first-best allocation of
resources.

4

I NTRODUCTION

A

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

CLASSIC VIEW

The policymaker roles are “classic.”
The monetary authority reacts to shocks each period in order to
achieve the Wicksellian natural real rate of interest for the economy.
The fiscal authority raises revenue via a non-state contingent linear
labor income tax on all households.
The labor market authority runs an unemployment insurance
program.
The education authority minimizes the variance of
beginning-of-life human capital endowments.

Hence, the main result is that classic policy prescriptions can achieve
the first-best allocation of resources in this benchmark
heterogeneous-agent economy.
This result may be helpful in understanding more complicated
economies that deviate from this benchmark.

5

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

S OME SURPRISING FINDINGS
The proposed classic policies appear broadly similar to actual
policies in place in many economies.
The monetary authority meets often and reacts to current
developments.
Simple linear labor income taxes set for the long run can be used
without distorting the labor supply; age-dependent taxation is
unnecessary.

The best policy combination drives the consumption Gini
toward zero but leaves income and financial wealth Ginis
substantially positive—suggesting that some observed income
and financial wealth inequality is due to life-cycle effects alone.
The model has a paper-and-pencil solution despite the three
aggregate shocks and the idiosyncratic risk.

6

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

S OME RECENT LITERATURE
Kaplan, Moll and Violante (“HANK,” AER, 2018).
Bhandari, Evans, Golosov and Sargent (ECMA, 2021,
forthcoming). Ramsey meets HANK.
Bullard and DiCecio (Working paper, St. Louis Fed, 2021).
Bullard and Singh (JMCB, 2020). NGDP targeting in a simpler
version.
Azariadis, Bullard, Singh and Suda (JEDC, 2019). Effective lower
bound.
Heathcote, Storesletten and Violante (JPubE, 2020).
Age-dependent taxation.
Koenig (IJCB, 2013). NGDP targeting.
Sheedy (BPEA, 2014). NGDP targeting.
Huggett, Ventura and Yaron (AER, 2011). Idiosyncratic risk at the
beginning of the life cycle.

7

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

Environment

8

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

L IFE - CYCLE MODELS
We construct a general-equilibrium life-cycle economy with
“symmetry assumptions” which could be relaxed in a
computational exercise.
Each period, a new continuum of households enters the
economy, makes economic decisions over the next T + 1 = 241
periods (“quarterly”), then exits the economy.
The symmetry assumptions:
All households have log preferences defined over consumption
and leisure.
All households have a discount factor of unity.
All households are endowed with a personal productivity profile
at the beginning of their life cycle which begins low, rises to a peak
exactly in the middle of the life cycle, and then declines in a
symmetric fashion.
The aggregate production technology is linear in the aggregate
effective labor input. We allow variable utilization of the labor
input.
9

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

P REFERENCES

Households are uncertain about how much they may wish to
consume in the future.

For the agent entering the economy at date t, preferences are
given by
T

Vt =

∑ η ln c̃t (t + s) + (1

η ) ln `t (t + s) ,

(1)

s=0

where c̃t (t + s)
given by

ct (t + s) D (t + s) and the state of demand D is
D (t + 1) = δ (t, t + 1) D (t) ,

(2)

where δ follows an AR (1) process with mean unity.
The preferences for other households are analogous and the
demand shock is experienced by all households at each date.
Following Bai, Ríos-Rull and Storesletten (manuscript, 2019), we
allow the state of aggregate demand to influence productive
activity in the economy.
10

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

P RODUCTION TECHNOLOGY
The linear production technology is given by
Y (t) = Q (t) D (t) N (t) L (t) ,

(3)

where L (t) is the aggregate effective labor input; Q (t) is the state
of technology which follows
Q (t + 1) = λ (t, t + 1) Q (t) ,

(4)

where λ follows an AR (1) process with mean λ̄ > 1; N (t) is the
population index which follows
N (t + 1) = ν (t, t + 1) N (t) ,

(5)

where ν follows an AR (1) process with mean ν̄ > 1.
The population index is understood to measure the
simultaneous increase or decrease in the size of all cohorts so as
to maintain symmetry. It can be viewed as “immigration.”
11

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

L IFE - CYCLE PRODUCTIVITY
Each household is randomly assigned a personal productivity
profile e = fe0 , e1 , ..., e240 g when entering the model.

Profiles are symmetric—they begin low, rise and peak exactly in
the middle of life, then decline symmetrically back to the low level.
Profiles are restricted to be consistent with interior solutions to all
household problems—households will choose to work low hours
but not zero.
Households also draw a scaling factor ξ from a lognormal
distribution as they enter the model, i.e., ln (ξ ) N µ, σ2 .

The product of their scaling factor and their assigned productivity
profile permanently determines their life-cycle productivity, that is, ξe.
Accordingly, there will be arbitrarily rich and arbitrarily poor
households in the economy.

For illustrative purposes, ξ is drawn from a uniform distribution
U [a, b] in the figures shown later.

12

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

R ATIONALE FOR A PERMANENT LIFE - CYCLE
PRODUCTIVITY ASSIGNMENT

The assignment of productivity profiles is a stand-in for the
human capital development that takes place before age 20 in
actual economies, including schooling, parenting and any job
experience.
Huggett, Ventura and Yaron (AER, 2011) argue that differences in
initial conditions (human capital at age 23) are more important
than subsequent shocks in explaining lifetime income.

13

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

B ASELINE LIFE - CYCLE PRODUCTIVITY
1.5

1

0.5

0

0

60

120

180

240

Quarters
F IGURE : A baseline personal productivity endowment profile. The profile is
symmetric and peaks in the middle period of the life cycle at a level about
50% greater than at the beginning or end. A full model would include a set of
symmetric profiles with differing shapes.

14

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

T HE MASS OF LIFE - CYCLE PRODUCTIVITY

F IGURE : The mass of endowment profiles with the scaling factor drawn from
a uniform distribution U [0.05, 1.95]. Drawing from a lognormal distribution
is harder to visualize, but such a distribution would include arbitrarily rich
and arbitrarily poor households.

15

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

A DDITIONAL IDIOSYNCRATIC RISK

Households can earn income in a competitive economywide
labor market by supplying hours along with the productivity
they have available at that date.
At the beginning of each period, each household may be
randomly unemployed.
The household earns no income from work on dates of
unemployment.
The unemployment probability is i.i.d. and uncorrelated with the
aggregate shock.

16

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

H OUSEHOLD CREDIT

The overlapping-generations structure creates a large private
credit market essential to good macroeconomic performance.
The key asset is therefore privately issued household debt.
As practical motivation, think of privately issued debt =
“mortgage-backed securities.”
U.S. household debt in the second quarter of 2021 was about $15
trillion, which was equal to about two-thirds of GDP.

17

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

N ON - STATE CONTINGENT NOMINAL CONTRACTING

There is a key friction in the credit market: non-state contingent
nominal contracting.
There are two aspects to this assumption.
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 through appropriate
monetary policy.

18

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

A DDITIONAL ASSUMPTIONS
There are no borrowing constraints.
See Azariadis et al. (JEDC, 2019) for a version with some
households excluded from credit markets.

There is stochastic labor force (= population) growth in this
version.
There is no default.
Prices are flexible.
Capital is fixed.
We ignore the effective lower bound in this version; see
Azariadis et al. (JEDC, 2019).
All policies are set credibly for all time t 2 ( ∞, +∞) .

19

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

Four Policymakers

20

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

F OUR POLICYMAKING ENTITIES

There are four policymaking entities.
The monetary authority can observe the three aggregate shocks at
the beginning of date t and then set the price level P (t) .
The fiscal authority can set taxes on labor or capital income to raise
an exogenously specified fraction of available real output.
The labor market authority observes household-specific
unemployment shocks, sets taxes and provides household-specific
transfers.
The education authority can control the initial dispersion of
life-cycle productivity profiles by controlling the standard
deviation of the scaling factor ξ up to some limit σmin 0.

21

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

T HE PROPOSED POLICY MIX

The proposed policy mix is as follows:
The monetary policymaker follows an NGDP targeting rule similar
to Koenig (IJCB, 2013) and Sheedy (BPEA, 2014).
The fiscal authority sets a linear tax on all labor income earned that
is sufficient to meet its revenue requirement.
The labor market authority sets a linear tax on all labor income
earned that is sufficient to provide appropriate transfers to
unemployed households.
The education authority minimizes the dispersion of life-cycle
productivity profiles by setting σ = σmin .

22

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

T HE W ICKSELLIAN NATURAL REAL RATE OF INTEREST
T HEOREM
Under the proposed policy mix, the real interest rate is exactly equal to the
stochastic aggregate output growth rate at every date, and an
equal-treatment social planner that discounts at this rate will conclude that
this is a social optimum.

C OROLLARY (E QUITY SHARE CONTRACTING )
Any two households that share the same productivity profile consume the
same amount at each date, and consumption growth is equalized for all
households.

C OROLLARY
Desired labor supply over the life cycle depends on the shape of the
productivity profile alone.

23

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

Characterizing the Policies

24

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

C HARACTERIZING THE POLICIES

We first describe how the monetary policy works.
We then characterize the equilibrium in a series of schematic
graphs representing the cross-sectional distribution of
households at each date.
In the graphs, we will show both the case where σmin = 0 and
the case where σmin > 0.
We can interpret this latter case as one where the education
policymaker cannot drive the variance of the scaling factor all the
way to zero.

25

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

M ONETARY POLICY
The monetary policymaker controls the price level P (t) directly
and meets a price level targeting criterion given by
P (t) =

λ (t

Rn (t 1, t)
1, t) ν (t 1, t) δ (t

1, t)

P (t

1) ,

(6)

where Rn (t 1, t), the gross nominal interest rate, is equal to the
expected gross rate of NGDP growth between dates t 1 and t.
The NGDP targeting rule works because it provides a form of
insurance for all households against current and future
aggregate shocks.
There is a multiplicity of monetary policy rules that can be used to
implement the price level targeting criterion. See Bullard and
Singh (JMCB, 2020).
See Giannoni and Woodford (2005) on targeting criteria.

26

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

E FFECTS OF AN AGGREGATE 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 the natural rate, i.e., a
decrease in λ, ν or δ, by increasing the inflation rate in the period of the
shock. Subsequently, inflation converges to its long-run equilibrium value
from below. The nominal interest rate drops in the period after the shock.
The Phillips curve correlation is high in this model.
27

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

L EISURE CHOICES AND TAX POLICY
Given the monetary policy, the labor market authority sets a tax
τ u that is linear in labor earnings.
The fiscal authority sets a tax τ f that is also linear in labor
earnings.
The household i first-order condition for leisure can then be
written as

`t,i (t + s) = (1
where ē =

1
T +1

η)

∑Ts=0 es and ēi =

ēi
= (1
es,i

1
T +1

η)

ē
, 8i,
es

(7)

∑Ts=0 es,i .

The scaling factor ξ and the two taxes τ u and τ f are all linear in e
and therefore cancel out in this expression—so taxing in this
manner is nondistortionary.
This result requires that all labor income is taxed at these rates
for all time.
28

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

H OURS WORKED OVER THE LIFE CYCLE
1

0.5

0

0

60

120

180

240

quarters
F IGURE : Cross section: Leisure decisions (green), labor supply decisions
(blue) and fraction of work time in U.S. data, 19% (red). The labor/leisure
choice depends on age only. High-income households plan to work the same
hours as low-income households at each age. A certain percentage of the
continuum of households in each cohort is unemployed but insured.

29

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

E DUCATION POLICY
“Education policy” influences the productivity profile dispersion
parameter σ.
One could interpret this as an idealized insurance market that
operates before households enter the economy at age 20.
Limiting case: σmin = 0, all households receive the same profile.
This would be a “perfectly equal” economy in that the talent
distribution would collapse to just one life-cycle pattern.
This would drive the consumption Gini to zero.
However, the income and wealth Gini coefficients would remain
close to observed values—these are driven mostly by the life-cycle
structure.

We will show both the idealized case σmin = 0 and cases where
σmin > 0 in a later slide.

30

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

Characterizing the Equilibrium

31

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

L ABOR INCOME

Households want to work more when they are in their peak
earning years in the middle of the life cycle.
This creates substantial labor income inequality.

32

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

L ABOR INCOME MASS

F IGURE : Cross section: Labor income profiles with unemployment insurance.
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. The blue line depicts the limiting case with σmin = 0.

33

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

C ONSUMPTION MASS

F IGURE : Cross section: Schematic consumption mass (red) and labor income
mass (blue). Under optimal monetary policy, the private credit market
reallocates uneven labor income into perfectly equal consumption along each
productivity profile. The consumption Gini is 32%, by construction the same
value as in U.S. data. The solid lines depict the limiting case with σmin = 0.

34

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

C ONSUMPTION EVOLUTION

F IGURE : Time series: Evolution of the distribution of log consumption
(shaded area) and examples of individual log consumption profiles (colored
lines). Under optimal monetary policy, individual consumption profiles
share the same stochastic trend as aggregate consumption.
35

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

N ET ASSET HOLDING MASS

F IGURE : Cross section: Schematic net asset holding mass relative to GDP by
cohort. 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 72.4%, similar to values calculated in U.S. data. The
blue line depicts the limiting case with σmin = 0.
36

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

T HREE NOTIONS OF INCOME

Three notions of income:
Pretax labor income, Y1 .
Pretax labor income plus non-negative capital income, Y2 .
The non-negative component of total income, Y3 .

Gini coefficients of income distributions: GY1 = 55.7%,
GY2 = 51.1%, GY3 = 59.0%.

37

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

L ABOR INCOME + NON - NEGATIVE CAPITAL INCOME

F IGURE : Cross section: Profiles of labor income and non-negative capital
income. The blue line depicts the limiting case with σmin = 0.

38

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

N ON - NEGATIVE TOTAL INCOME

F IGURE : Cross section: Profiles of non-negative total income. The blue line
depicts the limiting case with σmin = 0.

39

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

M ARGINAL PROPENSITY TO CONSUME
Consumption is linear in the real wage
ct,i (t + s) = ηξē 1

τ f (1

τ u ) w (t + s) .

Labor income is linear in the real wage
Y1;t,i (t + s) = ξes [1

`t (t + s)] 1

τ f (1

τ u ) w (t + s) .

Hence, the MPC can be calculated as follows:
MPC

=
=

ηēξ 1 τ f (1 τ u )
dc/dw
h
i
=
dY1 /dw
es ξ 1 (1 η ) eēs 1 τ f (1
es

τu )

=

ηē
.
(1 η ) ē

40

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

Y OUNG AND OLD AGENTS HAVE HIGH MPC
poor hand-to-mouth
8 consumers

wealthy hand-to-mouth
consumers

6
4
2
1
0
0

60

120

180

240

quarters
F IGURE : Cross section: Marginal propensity to consume out of labor income
by cohort. Notice that the MPC does not depend on the endowment scaling
factor, ξ.
41

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

Inequality

42

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

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%.

43

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

G INI COEFFICIENTS

Wealth
W
U.S. data
Model

Y1

80%
72.4%

Income
Y2

Y3

51%
55.7%

51.1%

Consumption
C
32%

59.0%

32%

TABLE : Gini coefficients in the U.S. data and in the model with lognormal
productivity.

44

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

P RODUCTIVITY DISPERSION AND G INI COEFFICIENTS
1

0.653
0.5
0.443

0
0

0.5

1

1.5

2

2.5

3

3.5

F IGURE : As the dispersion of productivity profiles, σ, increases, the Gini
coefficients increase. The ordering GW > GY > GC is preserved. The case
where σmin = 0 has GC = 0, but GW = 65.3% and GY = 44.3%. The model
can match any single Gini with a sufficiently large choice of σ.

45

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

Conclusions

46

I NTRODUCTION

E NVIRONMENT

F OUR POLICYMAKERS

P OLICY

E QUILIBRIUM

I NEQUALITY

C ONCLUSIONS

C ONCLUSIONS
A classic combination of policies can deliver a first-best
allocation of resources in this environment even with substantial
inequality in income, wealth and consumption.
A monetary policymaker provides period-by-period insurance
against aggregate shocks.
This enables nondistortionary linear labor income taxes to fund
government expenditures as well as an unemployment insurance
program.
Education policy can drive the consumption Gini toward zero but
would leave income and wealth Ginis at positive levels.

These classic benchmarks may be useful in understanding the
effects of macroeconomic policy for models in this class going
forward.

47