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Sources of U.S. Wealth Inequality in the Past, Present, and Future and Past, Present, and Future Marginal Propensities to Consume Joachim Hubmer, Per Krusell, Tony Smith UPenn, IIES, Yale Graduate Center@CUNY, February 2021
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Page 1: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Sources of U.S. Wealth Inequality in thePast, Present, and Future

andPast, Present, and Future Marginal

Propensities to Consume

Joachim Hubmer, Per Krusell, Tony SmithUPenn, IIES, Yale

Graduate Center@CUNY, February 2021

Page 2: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Extremely brief history of modern macro

I frustration with keynesian economics on methodologicalgrounds:I lucas critiqueI seemingly unstable relationshipsI hard to conduct welfare analysis

I lucas, sargent, wallace, etc. proposed to build newmacroeconomic models based on microeconomic foundations

I for decades, models remained very simple and stylizedI toy models, i.e., not quantitatively seriousI no econometric evaluationI markets (mostly) workI representative agent

I representative-agent assumption most challenging to drop

I conceptual, theoretical, and computational advances since mid1990s have now born fruit: heterogeneous-agent macro

Page 3: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Heterogeneous-agent macro

I now seems ubiquitousI business cyclesI monetary economics

I . . . and less and less difficult to study (numerically)I it has delivered

I a framework with higher propensities to consumeI a framework for analyzing equilibrium inequality (in

consumption, wealth, etc.)

I in this piece we evaluate the benchmark model’s quantitativeimplications of these over timeI what is/has been the evolution of mpcs?I what is/has been the evolution of wealth inequality?

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MPCs

simplest possible consumption-saving model, in macroeconomicsteady state:

max{ct ,at+1}∞t=0

∞∑t=0

βtu(ct)

s.t.ct + kt+1 = kt(1 + r − δ) + w for all t

in a steady state, β(1 + r − δ) = 1, so we obtain, for all t,

kt = k0 and ct = k0(r − δ) + w

hence MPC out of wealth is r − δ: super-small!

this is a robust result—so what does the data say?

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Average MPCs

cut/paste from Patterson (2019)

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Dispersion

more cut/paste from Patterson (2019)

Page 7: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Heterogeneous-agent models

the standard model (huggett-aiyagari)

I has idiosyncratic, partially uninsurable shocks

I non-trivial wealth distribution

I and mpc heterogeneity

high mpcs for “people in need”, i.e., those with

I low income realizations

I low liquid wealth

I so with low wealth (esp. close to borrowing constraint)

in this paper: for a quantitative model of this kind, i.e., one that

I matches wealth distribution on average

I and over time

ask whether the mpc distribution looks like in the data, how it hasevolved, and how it will evolve

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Evolution of top wealth inequality in the U.S.

1920 1930 1940 1950 1960 1970 1980 1990 2000 20105

10

15

20

25

30

35

40

45

50

55W

ealth S

hare

in %

Capitalization (SZ), Top 1%

Capitalization (SZ), Top 0.1%

SCF+, Top 1%

SCF+, Top 0.1%

Capitalization (SZZ), Top 1%

Capitalization (SZZ), Top 0.1%

Data: Kopczuk 2015, Saez & Zucman 2016, Smith, Zidar, and Zwick(2019).

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Goals, more specifically

1. evaluate basic model against the wealth dataI examine a quantitative macro model with sharp implications

for the distribution of wealth: can it match the data?I its average shapeI its evolution over time

I in particular, study the role of a number of wealth-inequalitydeterminants: marginal tax rates, preferences, earnings, andportfolio returns—all varying across households and over time

I we tie all of the parameters to micro data; does the benchmarkframework do an adequate job?

2. examine (the evolution of the) implied mpc distribution

Page 10: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Overview: findings

1. wealth distribution evaluationI average shape:

I yesI due to portfolio heterogeneity, very small (or no) role for

preference heterogeneity

I dynamic evolution:I yes, except for very, very topI lower tax progressivity plays key role for cumulativeI portfolio heterogeneity and asset prices key for swingsI earnings variance plays little role

I predictions for future: slow but significant further widening ofinequality

2. mpc distributionI MUCH higher on average than in RA model, but perhaps too

low, significant heterogeneity

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Quantitative model

I extended Aiyagari 1994 framework:I log labor income as sum of persistent and transitory

component; adjusted at the top to match the observed Paretotail in labor income

I transitory component incorporates zero earnings stateI heterogeneous returns: reduced-form portfolio choice, returns

increasing in wealth and have i.i.d. idiosyncratic componentI stochastic discount factor follows AR(1) process

(Krusell-Smith 1998 extended)I progressive taxation: use data on federal effective tax rates for

11 income brackets (Piketty & Saez 2007)I parsimonious modeling of social safety net: 60% of tax

revenues rebated as lump-sum transfers

I time-varying tax system, labor income process, and excessreturns

I finding: saving rates (key consumer choice) very robust andunresponsive to all drivers

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Return heterogeneity

I total return given asset holdings at is

r t + rXt (at) + σX (at)ηt

I r t is endogenous

I rXt (·) and σX (·) are exogenous excess return schedules (meanand st.dev.), taken from the data

I ηt is an i.i.d. standard normal shock

I rationalize as reduced form of portfolio choice model

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The consumer’s problem

Vt(xt , pt , βt) = maxat+1≥a

{u(xt − at+1) + βtE [Vt+1(xt+1, pt+1, βt+1)|pt , βt ]}

subject to: xt+1 = at+1 + yordt+1 − τ ordt+1(yord

t+1) + (1− τ cgt+1)y cgt+1 + Tt+1

yordt+1 = (r t+1 + rXt+1(at+1))at+1 + wt+1lt+1(pt+1, νt+1)

y cgt+1 = σX (at+1)ηt+1at+1

xt cash on handpt persistent component of earnings processlt+1(·, ·) efficiency units of labor, moves over timeνt+1 transitory earnings shockτordt (·) progressive tax on ordinary income, moves over timeτ cgt flat capital gains taxTt lump-sum transfer

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Whence wealth inequality?

I a dynasty model with complete markets, identical (standard)preferences and returns: generates no long-run wealthinequality beyond initial conditions => inadequate model ofwealth inequality

I incomplete markets added: has predictions, i.e., generatesunique distribution in steady state

I Aiyagari (1994) delivers far too little wealth inequality: Gini ofwealth becomes that of earnings (in data: >>)

I the literature has struggled with this (no clear consensus)I finite lives/OG?I preference heterogeneityI returns increase with wealth, entrepreneursI different earnings processes

I here:I no “tricks”: just feed in micro observations, works wellI portfolio heterogeneity important but next step is to explain it!

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Nontrivial mechanisms at top of the distribution

I in the data, both earnings and wealth distribution have Paretoshapes at the topI again, wealth has a fatter tail (lower Pareto coefficient)

I we calibrate earnings as in Aiyagari but add Paretodistribution at the top—calibrated to dataI this generates Pareto in wealth but with same coefficient =>

too thin a tail

I however: stochastic returns or βs generate a Pareto tail in thewealth distribution endogenously!I follows from random growth theory (Kesten 1973, see also

Gabaix 2009)I mechanism has been employed by Benhabib, Bisin and Zhu

2015, Nirei & Aoki 2015, Piketty & Zucman 2015

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Calibration strategy

1. calibrate earnings process, tax rates, return process, socialsafety net to observables

2. choose randomness in discount factor residually so as toreplicate the wealth distribution in the initial steady state(1967)

note: focus on tail coefficient alone misleading—even if, say, therichest 10% can be described exactly by a Pareto distribution, theshape parameter only tells us how wealth is distributed withinthese 10%, not how much wealth the top 10% control as a fractionof total wealth

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Calibration: return process

rXt (at) =∑c∈C

wc(at)(rc,t + rXc (at)

)(σX (at)

)2=∑c∈C

(wc(at)σ

Xc (at)

)2

I asset classes C : risk-free, public equity, private equity, housing

I rc,t : aggregate return on asset class c (U.S. data),time-varying

I fixed over time, based on Swedish administrative data fromBach, Calvet, Sodini (2016):I wc(·): portfolio weightsI rXc (·): within asset class return heterogeneityI σX

c (·): asset c idiosyncratic return standard deviation

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Portfolio holdings

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Schedule of excess returns

P0-P40

P40-P50

P50-P60

P60-P70

P70-P80

P80-P90

P90-P95

P95-P97.5

P97.5-P99

P99-P99.5

P99.5-P99.9

P99.9-P99.99

Top 0.01%

0

0.05

0.1

0.15

0.2

0.25

0.3

mean excess return

standard deviation

Data sources: Bach, Calvet, Sodini (2019); Kartashova (2014); Jorda,Knoll, Kuvshinov, Schularick, Taylor (2019); Case-Shiller.

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Results, I: steady state (1967)

Top 10% Top 1% Top 0.1% Top 0.01%

Data 70.8% 27.8% 9.4% 3.1%Model 66.6% 23.7% 11.2% 7.2%

Bottom 50% Fraction a < 0

Data 4.0% 8.0%Model 3.5% 7.3%

I model matches wealth distribution well on its entire domainI return heterogeneity is key ingredientI wealth concentration is mitigated by progressive taxation and

labor income risk

Page 21: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Observed change 1: decrease in tax progressivity

I federal effective tax rates (Piketty & Saez 2007): income,payroll, corporate and estate taxes

1970 1975 1980 1985 1990 1995 20000.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

top rate

5*average income

3*average income

average income

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Observed change 2: increase in labor income risk

I estimates for variance of persistent and temporary components1967-2000 (Heathcote, Storesletten & Violante 2010)

1970 1975 1980 1985 1990 1995 2000 2005 20100.1

0.2

0.3

0.4

0.5

0.6cross-sectional standard deviations

persistent component

transitory component

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Observed change 3: increase in top labor income sharesI adjust standard AR(1) in idiosyncratic productivity by

imposing a Pareto tail for the top 10% earners: calibrated tailcoefficient decreases from 2.8 to 1.9 (updated Piketty & Saez2003 series)

1970 1980 1990 2000 2010

25

30

35

top 10% share

model

data

1970 1980 1990 2000 2010

6

8

10

12

14

top 1% share

1970 1980 1990 2000 2010

1

2

3

4

5

top 0.1% share

1970 1980 1990 2000 2010

0.5

1

1.5

2

top 0.01% share

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Observed change 4: return premia

I feed in (smoothed) time series of aggregate U.S. asset premia(Kartashova 2014, Case-Shiller index)

1970 1975 1980 1985 1990 1995 2000 2005 2010 2015-0.05

0

0.05

0.1

0.15

0.2

housing

Page 25: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Observed change 4: return premia

I feed in (smoothed) time series of aggregate U.S. asset premia(Kartashova 2014, Case-Shiller index)

1970 1975 1980 1985 1990 1995 2000 2005 2010 2015-0.05

0

0.05

0.1

0.15

0.2

housing

public equity

Page 26: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Observed change 4: return premia

I feed in (smoothed) time series of aggregate U.S. asset premia(Kartashova 2014, Case-Shiller index)

1970 1975 1980 1985 1990 1995 2000 2005 2010 2015-0.05

0

0.05

0.1

0.15

0.2

housing

public equity

private equity

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Results, II: historical evolution

1970 1975 1980 1985 1990 1995 2000 2005 201060

65

70

75

80top 10% wealth share

model

data (SZ)

data (SZZ)

1970 1975 1980 1985 1990 1995 2000 2005 201020

25

30

35

40

45top 1% wealth share

1970 1975 1980 1985 1990 1995 2000 2005 20105

10

15

20

25top 0.1% wealth share

1970 1975 1980 1985 1990 1995 2000 2005 20102

4

6

8

10

12top 0.01% wealth share

Page 28: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Summary of transitional dynamics

I model captures the salient features of the evolution of theU.S. wealth distribution

I these results are robustI perfect foresight not critical ( details )I robust to CES production function with elasticity > 1 and

more generally falling labor share ( details )

I shortcomings:I explosion of wealth concentration at the extreme top (0.01%)

not fully captured quantitatively

Page 29: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Decomposition of transitional dynamics

I overall increase in wealth inequality (more than) fullyexplained by declining tax progressivityI primarily due to direct effect on resource distribution and not

due to changing savings behavior details

I time-varying return premia account for U-shape in wealthinequality

I subtle role of increasing earnings dispersionI thickening Pareto tail in labor income contributes slightly

positively to wealth inequalityI increase in overall earnings risk decreases wealth inequality

Page 30: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Capital in the 21st century?

1980 2000 2020 2040 2060 2080 210020

30

40

50

60

70

80top 1% wealth share

model

data (SZ)

data (SZZ)

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MPC distributions

I experiment: spending out of a surprise, one-time transfer of$100

I people respond based on their individual state (at , pt , βt):I heterogeneity also from βtI cash-on-hand at now has a return component in itI consumption choice made in advance of knowing return shock,

however (and it’s iid)

I we first report the average in the population—evaluated atthe relevant distribution at time t. . .

I and then show some details of the distribution

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The averages

1970 1980 1990 2000 2010 2020 2030

year

0.12

0.14

0.16

0.18

0.2average MPC

model

1970 1980 1990 2000 2010 2020 2030

year

0.78

0.8

0.82

0.84

0.86

0.88

0.9Gini coefficient of wealth distribution

model

1970 1980 1990 2000 2010 2020 2030

year

0.2

0.25

0.3

0.35

0.4

0.45top 1% wealth share

model

data (SZ)

data (SZZ)

1970 1980 1990 2000 2010 2020 2030

0.01

0.015

0.02

0.025

0.03

0.035

0.04

bottom 50% wealth share

model

data (SCF)

Page 33: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

The heterogeneity

0 20 40 60 80 100

percentile of MPC distribution

0

0.2

0.4

0.6

0.8

1

MP

C

1980

2020

2050

Page 34: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Time change driven by change in distribution ofcash-on-hand

0 20 40 60 80 100

percentile of cash-on-hand distribution

0

0.2

0.4

0.6

0.8

1

MP

C

1967

1980

2000

2020

-2 -1 0 1 2 3 4 5 6

log cash-on-hand

0

0.2

0.4

0.6

0.8

1

MP

C

1967

1980

2000

2020

Page 35: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Concluding comments

I main findings:I account for most long-run inequality w/o β heterogeneityI account well for historical evolution due to taxes (trend) and

asset-price movements (swings); exception: the very topI significantly higher average mpc and high dispersion accounted

for but maybe not enough?I mpcs significantly higher now than in 1970

I remaining questions:I missing rise at top: increased idiosyncratic return volatility,

shift toward private equity?I why are portfolios heterogeneous (both across and within

wealth levels), what drives returns?I interactions with aggregate risk

Page 36: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

thanks for your attention

wanna see the appendix?

Page 37: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Trends in wealth inequality: recent literature

I data: Saez and Zucman 2015, Kopczuk 2015, Bricker,Henriques, Krimmel, and Sabelhaus 2016.

I models of Pareto tails: Piketty and Zucman 2015, Benhabib,Bisin, and Luo 2015, Nirei and Aoki 2015.

I models of transitions: Kaymak and Poschke 2016, Gabaix,Lasry, Lions, and Moll 2016, Aoki and Nirei 2016.

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Equilibrium: capital market clearing

need to find two equilibrium objects (Kt , r t) for market clearing:

1. aggregate capital (as usual)

Kt =

∫atdΓ(at)

2. aggregate capital income (redundant if rXt (·) = 0)

(MPK (Kt)− δ)Kt =

∫ (r t + rXt (at)

)atdΓ(at)

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Multiplicative shocks and Pareto tails

I linear savings rules as wealth grows large (Bewley 1977;Carroll 2012; Benhabib et al. 2015): limx→∞ s(x , β) = sβx .

I asset accumulation for large x :

at+1 = s(xt , β)

= s(at + yt − T (yt), β)

≈ sβat(1 + (1− τmax)r) + sβ(1− τmax)et

≡ sat + zt ,

where et is earnings.

I β and/or r random → s is random.

I with reflecting barrier (borrowing constraint) and/or randomearnings, the invariant distribution for wealth has a Pareto tailwith coefficient ζ solving: E[sζ ] = 1.

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Stochastic-β yields stochastic, linear savings decisions

2 4 6 8 10 12 14 16

log(k)

0.84

0.86

0.88

0.9

0.92

0.94

0.96

0.98

1

1.02m

arg

ina

l p

rop

en

sity t

o s

ave

high beta, high earnings

high beta, low earnings

low beta, high earnings

low beta, low earnings

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Gives rise to a Pareto tail in the wealth distribution

-5 0 5 10 15

log(k)

-18

-16

-14

-12

-10

-8

-6

-4

-2

0lo

g(P

rob

(K >

k))

log(Prob(K > k))

Top 10%

Top 1%

Top 0.1%

Top 0.01%

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Cumulative change in top wealth shares

Top 10% Top 1% Top 0.1% Top 0.01%

Data 1967 70.8 27.8 9.4 3.12012 77.2 41.8 22.0 11.2

Relative ∆ 9.0% 50.4% 134.0% 261.3%

Model 1967 73.8 27.4 8.4 3.22012 78.5 36.5 14.4 5.6

Relative ∆ 6.4% 33.2% 72.2% 75.4%

Fraction explained 70.8% 65.9% 53.8% 28.9%

Wealth shares in %.Data (capitalization): Saez & Zucman 2016.

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... when compared to SCF data

Top 10% Top 1% Top 0.1%

Data 1989 67.1 30.1 10.82013 75.3 35.8 13.5

Relative ∆ 12.2% 19.1% 25.4%

Model 1989 69.3 24.5 7.42013 78.9 37.1 14.8

Relative ∆ 13.7% 51.5% 100.3%

Fraction Explained 112.5% 270.1% 394.5%

Wealth shares in %.Data: SCF, as reported by Saez & Zucman 2016.

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Other parts of the distribution

Bottom 50% personal wealthY

nat’l wealthY

KY

Data 1967 4.0% 3.6 4.12010 1.1% 4.1 4.6Relative ∆ −73% 14% 14%

Model 1967 3.0% 4.02010 1.4% 4.4Relative ∆ −53% 10%

Fraction explained 74%

Bottom 50% Data: SCF, as reported by Kennickell 2011.Personal/national wealth data: Piketty & Zucman 2014.

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Excess return schedule details

Aggregate Excess Returns in 1967 steady state (over risk-freerate):

I public equity 0.067

I private equity 0.129

I housing 0.037 (incl. imputed rent)

P0-P40 P40-P50 P50-P60 P60-P70 P70-P80 P80-P90 P90-P95 P95-P97.5 P97.5-P99 P99-P99.5 P99.5-P99.9 P99.9-P99.99 Top 0.01%

fixed portfolio weights

cash 0.722 0.412 0.248 0.182 0.156 0.134 0.115 0.102 0.090 0.079 0.071 0.051 0.029housing 0.162 0.394 0.580 0.662 0.678 0.674 0.658 0.626 0.572 0.482 0.363 0.253 0.155public equity 0.113 0.189 0.165 0.147 0.153 0.170 0.189 0.207 0.219 0.232 0.230 0.185 0.179private equity 0.002 0.005 0.007 0.009 0.013 0.021 0.038 0.065 0.118 0.207 0.336 0.511 0.637

difference from aggregate return on asset class

cash 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000housing 0.000 0.000 0.002 0.004 0.005 0.007 0.009 0.010 0.010 0.011 0.010 0.010 0.011public equity 0.000 0.000 0.001 0.002 0.003 0.005 0.008 0.012 0.014 0.015 0.016 0.016 0.016private equity 0.000 0.000 -0.019 -0.030 -0.054 -0.055 -0.049 -0.066 -0.064 -0.063 -0.063 -0.059 -0.060

standard deviation of return on asset class

cash 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000housing 0.140 0.140 0.140 0.140 0.140 0.140 0.140 0.140 0.140 0.140 0.140 0.140 0.140public equity 0.035 0.035 0.031 0.031 0.031 0.031 0.032 0.033 0.035 0.038 0.042 0.046 0.053private equity 0.664 0.664 0.621 0.595 0.544 0.525 0.518 0.480 0.474 0.470 0.474 0.492 0.443private equity (re-scaled) 0.345 0.345 0.323 0.309 0.283 0.273 0.269 0.249 0.246 0.245 0.246 0.256 0.230

excess return schedule in 1967

mean excess return 0.000 0.011 0.017 0.020 0.022 0.026 0.031 0.035 0.041 0.050 0.062 0.079 0.091standard deviation 0.023 0.056 0.081 0.093 0.095 0.095 0.094 0.093 0.098 0.119 0.167 0.254 0.283st. dev. (priv.equ. re-scaled) 0.023 0.056 0.081 0.093 0.095 0.095 0.093 0.089 0.086 0.085 0.098 0.136 0.149

Page 46: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Housing details

I financial return on housing as sum of capital gains term andrental income

I we set capital gains term to zero in steady states (in long run0-0.5% real price growth)

I over transition, use growth in aggregate house price index(Case-Shiller)

I rental income set to 5.33% (average for U.S. from Jorda,Knoll, Kuvshinov, Schularick, Tayler ”Rate of Return onEverything”)

Page 47: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Public and private equity

Public Equity

I U.S. stock market return

Private Equity

I Kartashova (AER, 2014) documents private equity premiumover stock market

I aggregate time series for U.S. starting in 1960

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Capital in the 21st century?

Top 10% Top 1% Top 0.1% Top 0.01% Bottom 50%

1967 73.8 27.4 8.4 3.2 3.02017 80.0 39.2 16.2 6.5 1.22100 89.1 61.6 35.2 17.0 0.3

Model predictions for 21st century. Wealth shares in %.

I long-run effects of decrease in tax progressivity

Page 49: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Perfect foresight vs. myopic transition; CES return

1970 1980 1990 2000 201065

70

75

80

top 10% wealth share

benchmark

CES

myopic

1970 1980 1990 2000 201020

25

30

35

40top 1% wealth share

1970 1980 1990 2000 20106

8

10

12

14

16

18top 0.1% wealth share

1970 1980 1990 2000 20102

3

4

5

6

7top 0.01% wealth share

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Perfect foresight vs. myopic transition; CES return

1970 1980 1990 2000 20103.9

4

4.1

4.2

4.3

4.4

4.5

4.6capital - net output ratio

benchmark

CES

myopic

1970 1980 1990 2000 20101

1.5

2

2.5

3

3.5

4

4.5bottom 50% share

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Tax changes: changes in savings behavior vs. resources

1970 1980 1990 2000 201072

74

76

78

80

82

84

86top 10% wealth share

full equilibrium

new s(.), fix tax

fix s(.), new tax

1970 1980 1990 2000 201025

30

35

40

45

50top 1% wealth share

1970 1980 1990 2000 20108

10

12

14

16

18

20top 0.1% wealth share

1970 1980 1990 2000 20102

3

4

5

6

7

8

9top 0.01% wealth share

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Only changes in earnings risk I return

1970 1980 1990 2000 201060

65

70

75

80top 10% wealth share

model

data (SZ)

data (SCF)

1970 1980 1990 2000 201020

25

30

35

40

45top 1% wealth share

1970 1980 1990 2000 20105

10

15

20

25top 0.1% wealth share

1970 1980 1990 2000 20102

4

6

8

10

12top 0.01% wealth share

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Only changes in earnings risk II return

1970 1980 1990 2000 20103

3.5

4

4.5

5

5.5

6capital - net output ratio

model (capital)

data (national wealth)

data (private wealth)

1970 1980 1990 2000 20101

1.5

2

2.5

3

3.5

4bottom 50% share

model

data (SCF)

Page 54: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Only changes in top earnings shares I return

1970 1980 1990 2000 201060

65

70

75

80top 10% wealth share

model

data (SZ)

data (SCF)

1970 1980 1990 2000 201020

25

30

35

40

45top 1% wealth share

1970 1980 1990 2000 20105

10

15

20

25top 0.1% wealth share

1970 1980 1990 2000 20102

4

6

8

10

12top 0.01% wealth share

Page 55: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Only changes in top earnings shares II return

1970 1980 1990 2000 20103

3.5

4

4.5

5

5.5

6capital - net output ratio

model (capital)

data (national wealth)

data (private wealth)

1970 1980 1990 2000 20101

1.5

2

2.5

3

3.5

4bottom 50% share

model

data (SCF)

Page 56: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Only changes in taxes I return

1970 1980 1990 2000 201060

65

70

75

80

85top 10% wealth share

model

data (SZ)

data (SCF)

1970 1980 1990 2000 201020

25

30

35

40

45top 1% wealth share

1970 1980 1990 2000 20105

10

15

20

25top 0.1% wealth share

1970 1980 1990 2000 20102

4

6

8

10

12top 0.01% wealth share

Page 57: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Only changes in taxes II return

1970 1980 1990 2000 20103

3.5

4

4.5

5

5.5

6capital - net output ratio

model (capital)

data (national wealth)

data (private wealth)

1970 1980 1990 2000 20101

1.5

2

2.5

3

3.5

4bottom 50% share

model

data (SCF)

Page 58: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Only changes in return premia I return

1970 1980 1990 2000 201060

65

70

75

80top 10% wealth share

model

data (SZ)

data (SCF)

1970 1980 1990 2000 201020

25

30

35

40

45top 1% wealth share

1970 1980 1990 2000 20105

10

15

20

25top 0.1% wealth share

1970 1980 1990 2000 20102

4

6

8

10

12top 0.01% wealth share

Page 59: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Only changes in return premia II return

1970 1980 1990 2000 20103

3.5

4

4.5

5

5.5

6capital - net output ratio

model (capital)

data (national wealth)

data (private wealth)

1970 1980 1990 2000 20101

1.5

2

2.5

3

3.5

4

4.5bottom 50% share

model

data (SCF)

Page 60: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Dynamics in single-β model I

1970 1975 1980 1985 1990 1995 2000 2005 201060

65

70

75

80top 10% wealth share

model

data (SZ)

data (SZZ)

1970 1975 1980 1985 1990 1995 2000 2005 201020

25

30

35

40

45top 1% wealth share

1970 1975 1980 1985 1990 1995 2000 2005 20105

10

15

20

25top 0.1% wealth share

1970 1975 1980 1985 1990 1995 2000 2005 20102

4

6

8

10

12top 0.01% wealth share

Page 61: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Dynamics in single-β model II

1970 1975 1980 1985 1990 1995 2000 2005 20103

3.5

4

4.5

5

5.5

6capital - net output ratio

model (capital)

data (national wealth)

data (private wealth)

1970 1975 1980 1985 1990 1995 2000 2005 20101

1.5

2

2.5

3

3.5

4

4.5

5bottom 50% share

model

data (SCF)

Page 62: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Inflation I

1970 1980 1990 2000 2010

60

65

70

75

80

85top 10% wealth share

benchmark

benchmark +inflation

1970 1980 1990 2000 2010

15

20

25

30

35

40top 1% wealth share

1970 1980 1990 2000 2010

4

6

8

10

12

14

16

18top 0.1% wealth share

1970 1980 1990 2000 2010

1

2

3

4

5

6

7top 0.01% wealth share

Page 63: Sources of U.S. Wealth Inequality in the Past, Present, and Future … · 2021. 2. 18. · 11 income brackets (Piketty & Saez 2007) I parsimonious modeling of social safety net: 60%

Inflation II

1970 1980 1990 2000 2010

3.6

3.8

4

4.2

4.4

4.6capital - net output ratio

benchmark

benchmark +inflation

1970 1980 1990 2000 2010

1

2

3

4

5

6bottom 50% share


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