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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions Risk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric T. Swanson Economic Research Federal Reserve Bank of San Francisco Macroeconomics Seminar Birkbeck College, London November 7, 2013

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Page 1: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Risk Aversion, Risk Premia, and the Labor Marginwith Generalized Recursive Preferences

Eric T. Swanson

Economic ResearchFederal Reserve Bank of San Francisco

Macroeconomics SeminarBirkbeck College, London

November 7, 2013

Page 2: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Relative Risk Aversion

Suppose a household has preferences:

E0

∞∑t=0

βtu(ct , lt ),

u(ct , lt ) =c1−γ

t1− γ

− η lt

What is the household’s coefficient of relative risk aversion?

Answer: 0

Page 3: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Relative Risk Aversion

Suppose a household has preferences:

E0

∞∑t=0

βtu(ct , lt ),

u(ct , lt ) =c1−γ

t1− γ

− η lt

What is the household’s coefficient of relative risk aversion?

Answer: 0

Page 4: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Relative Risk Aversion

Suppose a household has preferences:

E0

∞∑t=0

βtu(ct , lt ),

u(ct , lt ) =c1−γ

t1− γ

− ηl1+χt

1 + χ

What is the household’s coefficient of relative risk aversion?

Answer:1

+1χ

Page 5: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Empirical Relevance of the Labor Margin

Imbens, Rubin, and Sacerdote (2001):Individuals who win a lottery prize reduce labor supply by $.11for every $1 won (note: spouse may also reduce labor supply)

Coile and Levine (2009):Older individuals are 7% less likely to retire in a given year aftera 30% fall in stock market

Coronado and Perozek (2003):Individuals who held more stocks in late 1990s retired 7 monthsearlier

Large literature estimating wealth effects on labor supply (e.g.,Pencavel 1986)

Page 6: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Outline of Presentation

Define risk aversion rigorously for expected utility preferences

Show the labor margin can have big effects on risk aversion

Generalize the results to Epstein-Zin preferences

Discuss asset pricing examples

See the paper for:

More asset pricing details

Numerical solutions far away from steady state

Multiplier preferences

Page 7: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Outline of Presentation

Define risk aversion rigorously for expected utility preferences

Show the labor margin can have big effects on risk aversion

Generalize the results to Epstein-Zin preferences

Discuss asset pricing examples

See the paper for:

More asset pricing details

Numerical solutions far away from steady state

Multiplier preferences

Page 8: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

A Household

Household preferences:

Et

∞∑τ=t

βτ−tu(cτ , lτ ),

Flow budget constraint:

aτ+1 = (1 + rτ )aτ + wτ lτ + dτ − cτ ,

No-Ponzi condition:

limT→∞

T∏τ=t

(1 + rτ+1)−1aT +1 ≥ 0,

{wτ , rτ ,dτ} are exogenous processes, governed by θτ

Page 9: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

The Value Function

State variables of the household’s problem are (at ; θt ).

Let:c∗t ≡ c∗(at ; θt ),

l∗t ≡ l∗(at ; θt ).

Value function, Bellman equation:

V (at ; θt ) = u(c∗t , l∗t ) + βEtV (a∗t+1; θt+1),

where:a∗t+1 ≡ (1 + rt )at + wt l∗t + dt − c∗t .

Page 10: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

The Value Function

State variables of the household’s problem are (at ; θt ).

Let:c∗t ≡ c∗(at ; θt ),

l∗t ≡ l∗(at ; θt ).

Value function, Bellman equation:

V (at ; θt ) = u(c∗t , l∗t ) + βEtV (a∗t+1; θt+1),

where:a∗t+1 ≡ (1 + rt )at + wt l∗t + dt − c∗t .

Page 11: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Technical Conditions

Assumption 1. The function u(ct , lt ) is increasing in its firstargument, decreasing in its second, twice-differentiable, and strictlyconcave.

Assumption 2. The value function V : X → R for the household’soptimization problem exists and satisfies the Bellman equation

V (at ; θt ) = max(ct ,lt )∈Γ(at ;θt )

u(ct , lt ) + βEtV (at+1; θt+1).

Assumption 3. For any (at ; θt ) ∈ X, the household’s optimalchoice (c∗t , l

∗t ) lies in the interior of Γ(at ; θt ).

Assumption 4. The value function V (·; ·) is twice-differentiable inits first argument. (It then follows that c∗, l∗ are differentiable.)

Page 12: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Assumptions about the Economic Environment

Assumption 5. The household is infinitesimal.

Assumption 6. The household is representative.

Assumption 7. The model has a nonstochastic steady state,xt = xt+k for k = 1,2, . . . , and x ∈ {c, l ,a,w , r ,d , θ}.

Assumption 7′. The model has a balanced growth path that canbe renormalized to a nonstochastic steady state after a suitablechange of variables.

Page 13: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Assumptions about the Economic Environment

Assumption 5. The household is infinitesimal.

Assumption 6. The household is representative.

Assumption 7. The model has a nonstochastic steady state,xt = xt+k for k = 1,2, . . . , and x ∈ {c, l ,a,w , r ,d , θ}.

Assumption 7′. The model has a balanced growth path that canbe renormalized to a nonstochastic steady state after a suitablechange of variables.

Page 14: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Static One-Good Model (Review)

Compare:E u(c + σε) vs. u(c − µ)

Compute:u(c − µ) ≈ u(c)− µu′(c),

µ =−u′′(c)

u′(c)

σ2

2.

Coefficient of absolute risk aversion is defined to be:

limσ→0

2µ(σ)/σ2 =−u′′(c)

u′(c).

Page 15: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Static One-Good Model (Review)

Compare:E u(c + σε) vs. u(c − µ)

Compute:u(c − µ) ≈ u(c)− µu′(c),

µ =−u′′(c)

u′(c)

σ2

2.

Coefficient of absolute risk aversion is defined to be:

limσ→0

2µ(σ)/σ2 =−u′′(c)

u′(c).

Page 16: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Static One-Good Model (Review)

Compare:E u(c + σε) vs. u(c − µ)

Compute:u(c − µ) ≈ u(c)− µu′(c),

E u(c + σε) ≈ u(c) + u′(c)σE [ε] +12

u′′(c)σ2E [ε2],

µ =−u′′(c)

u′(c)

σ2

2.

Coefficient of absolute risk aversion is defined to be:

limσ→0

2µ(σ)/σ2 =−u′′(c)

u′(c).

Page 17: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Static One-Good Model (Review)

Compare:E u(c + σε) vs. u(c − µ)

Compute:u(c − µ) ≈ u(c)− µu′(c),

E u(c + σε) ≈ u(c) +12

u′′(c)σ2.

µ =−u′′(c)

u′(c)

σ2

2.

Coefficient of absolute risk aversion is defined to be:

limσ→0

2µ(σ)/σ2 =−u′′(c)

u′(c).

Page 18: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Static One-Good Model (Review)

Compare:E u(c + σε) vs. u(c − µ)

Compute:u(c − µ) ≈ u(c)− µu′(c),

E u(c + σε) ≈ u(c) +12

u′′(c)σ2.

µ =−u′′(c)

u′(c)

σ2

2.

Coefficient of absolute risk aversion is defined to be:

limσ→0

2µ(σ)/σ2 =−u′′(c)

u′(c).

Page 19: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Static One-Good Model (Review)

Compare:E u(c + σε) vs. u(c − µ)

Compute:u(c − µ) ≈ u(c)− µu′(c),

E u(c + σε) ≈ u(c) +12

u′′(c)σ2.

µ =−u′′(c)

u′(c)

σ2

2.

Coefficient of absolute risk aversion is defined to be:

limσ→0

2µ(σ)/σ2 =−u′′(c)

u′(c).

Page 20: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Dynamic Model

Consider a one-shot gamble in period t :

at+1 = (1 + rt )at + wt lt + dt − ct + σεt+1, (∗)

Note we cannot easily consider gambles over:ct (choice variable)at (state variable, already known at t)

Note (∗) is equivalent to gamble over asset returns:

at+1 = (1 + rt + σεt+1)at + wt lt + dt − ct .

or income:

at+1 = (1 + rt )at + wt lt + (dt + σεt+1)− ct ,

Page 21: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Dynamic Model

Consider a one-shot gamble in period t :

at+1 = (1 + rt )at + wt lt + dt − ct + σεt+1, (∗)

Note we cannot easily consider gambles over:ct (choice variable)at (state variable, already known at t)

Note (∗) is equivalent to gamble over asset returns:

at+1 = (1 + rt + σεt+1)at + wt lt + dt − ct .

or income:

at+1 = (1 + rt )at + wt lt + (dt + σεt+1)− ct ,

Page 22: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Dynamic Model

Consider a one-shot gamble in period t :

at+1 = (1 + rt )at + wt lt + dt − ct + σεt+1, (∗)

Note we cannot easily consider gambles over:ct (choice variable)at (state variable, already known at t)

Note (∗) is equivalent to gamble over asset returns:

at+1 = (1 + rt + σεt+1)at + wt lt + dt − ct .

or income:

at+1 = (1 + rt )at + wt lt + (dt + σεt+1)− ct ,

Page 23: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Dynamic Model

Consider a one-shot gamble in period t :

at+1 = (1 + rt )at + wt lt + dt − ct + σεt+1, (∗)

Note we cannot easily consider gambles over:ct (choice variable)at (state variable, already known at t)

Note (∗) is equivalent to gamble over asset returns:

at+1 = (1 + rt + σεt+1)at + wt lt + dt − ct .

or income:

at+1 = (1 + rt )at + wt lt + (dt + σεt+1)− ct ,

Page 24: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Dynamic Model

Consider a one-shot gamble in period t :

at+1 = (1 + rt )at + wt lt + dt − ct + σεt+1,

vs.

at+1 = (1 + rt )at + wt lt + dt − ct − µ.

Welfare loss from µ:

Page 25: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Dynamic Model

Consider a one-shot gamble in period t :

at+1 = (1 + rt )at + wt lt + dt − ct + σεt+1,

vs.

at+1 = (1 + rt )at + wt lt + dt − ct − µ.

Welfare loss from µ:V1(at ; θt )

µ

(1 + rt )

Page 26: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Dynamic Model

Consider a one-shot gamble in period t :

at+1 = (1 + rt )at + wt lt + dt − ct + σεt+1,

vs.

at+1 = (1 + rt )at + wt lt + dt − ct − µ.

Welfare loss from µ:

βEtV1(a∗t+1; θt+1)µ.

Page 27: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Arrow-Pratt in a Dynamic Model

Consider a one-shot gamble in period t :

at+1 = (1 + rt )at + wt lt + dt − ct + σεt+1,

vs.

at+1 = (1 + rt )at + wt lt + dt − ct − µ.

Welfare loss from µ:

βEtV1(a∗t+1; θt+1)µ.

Loss from σ:

βEtV11(a∗t+1; θt+1)σ2

2.

Page 28: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Definition 1. The household’s coefficient of absolute risk aversionat (at ; θt ) is given by Ra(at ; θt ) = limσ→0 2µ(σ)/σ2.

Page 29: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Definition 1. The household’s coefficient of absolute risk aversionat (at ; θt ) is given by Ra(at ; θt ) = limσ→0 2µ(σ)/σ2.

Proposition 1. The household’s coefficient of absolute riskaversion at (at ; θt ) is well defined and given by

Ra(at ; θt ) =−EtV11(a∗t+1; θt+1)

EtV1(a∗t+1; θt+1).

Page 30: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Definition 1. The household’s coefficient of absolute risk aversionat (at ; θt ) is given by Ra(at ; θt ) = limσ→0 2µ(σ)/σ2.

Proposition 1. The household’s coefficient of absolute riskaversion at (at ; θt ) is well defined and given by

Ra(at ; θt ) =−EtV11(a∗t+1; θt+1)

EtV1(a∗t+1; θt+1).

folk wisdom: Constantinides (1990), Farmer (1990), Boldrin-Christiano-Fisher (1997, 2001), Campbell-Cochrane (1999), Flavin-Nakagawa(2008)

Page 31: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Definition 1. The household’s coefficient of absolute risk aversionat (at ; θt ) is given by Ra(at ; θt ) = limσ→0 2µ(σ)/σ2.

Proposition 1. The household’s coefficient of absolute riskaversion at (at ; θt ) satisfies

Ra(at ; θt ) =−EtV11(a∗t+1; θt+1)

EtV1(a∗t+1; θt+1).

Evaluated at the nonstochastic steady state, this simplifies to:

Ra(a; θ) =−V11(a; θ)

V1(a; θ).

folk wisdom: Constantinides (1990), Farmer (1990), Boldrin-Christiano-Fisher (1997, 2001), Campbell-Cochrane (1999), Flavin-Nakagawa(2008)

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for V1 and V11

Benveniste-Scheinkman:

V1(at ; θt ) = (1 + rt ) u1(c∗t , l∗t ). (∗)

Differentiate (∗) to get:

V11(at ; θt ) = (1 + rt )

[u11(c∗t , l

∗t )∂c∗t∂at

+ u12(c∗t , l∗t )∂l∗t∂at

].

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for V1 and V11

Benveniste-Scheinkman:

V1(at ; θt ) = (1 + rt ) u1(c∗t , l∗t ). (∗)

Differentiate (∗) to get:

V11(at ; θt ) = (1 + rt )

[u11(c∗t , l

∗t )∂c∗t∂at

+ u12(c∗t , l∗t )∂l∗t∂at

].

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for ∂l∗t /∂at and ∂c∗t /∂at

Household intratemporal optimality: −u2(c∗t , l∗t ) = wt u1(c∗t , l

∗t ).

Differentiate to get:∂l∗t∂at

= −λt∂c∗t∂at

,

λt ≡wtu11(c∗t , l

∗t ) + u12(c∗t , l

∗t )

u22(c∗t , l∗t ) + wtu12(c∗t , l

∗t ).

Household Euler equation:

u1(c∗t , l∗t ) = βEt (1 + rt+1) u1(c∗t+1, l

∗t+1),

Differentiate, substitute out for ∂l∗t /∂at , and use BC, TVC to get:

∂c∗t∂at

=r

1 + wλ.

Page 35: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for ∂l∗t /∂at and ∂c∗t /∂at

Household intratemporal optimality: −u2(c∗t , l∗t ) = wt u1(c∗t , l

∗t ).

Differentiate to get:∂l∗t∂at

= −λt∂c∗t∂at

,

λt ≡wtu11(c∗t , l

∗t ) + u12(c∗t , l

∗t )

u22(c∗t , l∗t ) + wtu12(c∗t , l

∗t ).

Household Euler equation:

u1(c∗t , l∗t ) = βEt (1 + rt+1) u1(c∗t+1, l

∗t+1),

Differentiate, substitute out for ∂l∗t /∂at , and use BC, TVC to get:

∂c∗t∂at

=r

1 + wλ.

Page 36: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for ∂l∗t /∂at and ∂c∗t /∂at

Household intratemporal optimality: −u2(c∗t , l∗t ) = wt u1(c∗t , l

∗t ).

Differentiate to get:∂l∗t∂at

= −λt∂c∗t∂at

,

λt ≡wtu11(c∗t , l

∗t ) + u12(c∗t , l

∗t )

u22(c∗t , l∗t ) + wtu12(c∗t , l

∗t ).

Household Euler equation:

u1(c∗t , l∗t ) = βEt (1 + rt+1) u1(c∗t+1, l

∗t+1),

Differentiate, substitute out for ∂l∗t /∂at , and use BC, TVC to get:

∂c∗t∂at

=r

1 + wλ.

Page 37: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for ∂l∗t /∂at and ∂c∗t /∂at

Household intratemporal optimality: −u2(c∗t , l∗t ) = wt u1(c∗t , l

∗t ).

Differentiate to get:∂l∗t∂at

= −λt∂c∗t∂at

,

λt ≡wtu11(c∗t , l

∗t ) + u12(c∗t , l

∗t )

u22(c∗t , l∗t ) + wtu12(c∗t , l

∗t ).

Household Euler equation:

u1(c∗t , l∗t ) = βEt (1 + rt+1) u1(c∗t+1, l

∗t+1),

Differentiate, substitute out for ∂l∗t /∂at , and use BC, TVC to get:

∂c∗t∂at

=r

1 + wλ.

Page 38: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for ∂l∗t /∂at and ∂c∗t /∂at

Household intratemporal optimality: −u2(c∗t , l∗t ) = wt u1(c∗t , l

∗t ).

Differentiate to get:∂l∗t∂at

= −λt∂c∗t∂at

,

λt ≡wtu11(c∗t , l

∗t ) + u12(c∗t , l

∗t )

u22(c∗t , l∗t ) + wtu12(c∗t , l

∗t ).

Household Euler equation:

u1(c∗t , l∗t ) = βEt (1 + rt+1) u1(c∗t+1, l

∗t+1),

Differentiate, substitute out for ∂l∗t /∂at , and use BC, TVC to get:

∂c∗t∂at

=r

1 + wλ.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for Coefficient of Absolute Risk Aversion

V1(a; θ) = (1 + r) u1(c, l),

V11(a; θ) = (1 + r)

[u11(c, l)

∂c∗t∂at

+ u12(c, l)∂l∗t∂at

],

∂l∗t∂at

= −λ∂c∗t∂at

,

∂c∗t∂at

=r

1 + wλ.

Proposition 2. The household’s coefficient of absolute riskaversion in Proposition 1, evaluated at steady state, satisfies:

Ra(a; θ) =−V11(a; θ)

V1(a; θ)=−u11 + λu12

u1

r1 + wλ

.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for Coefficient of Absolute Risk Aversion

V1(a; θ) = (1 + r) u1(c, l),

V11(a; θ) = (1 + r)

[u11(c, l)

∂c∗t∂at

+ u12(c, l)∂l∗t∂at

],

∂l∗t∂at

= −λ∂c∗t∂at

,

∂c∗t∂at

=r

1 + wλ.

Proposition 2. The household’s coefficient of absolute riskaversion in Proposition 1, evaluated at steady state, satisfies:

Ra(a; θ) =−V11(a; θ)

V1(a; θ)=−u11 + λu12

u1

r1 + wλ

.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for Coefficient of Absolute Risk Aversion

V1(a; θ) = (1 + r) u1(c, l),

V11(a; θ) = (1 + r)

[u11(c, l)

∂c∗t∂at

+ u12(c, l)∂l∗t∂at

],

∂l∗t∂at

= −λ∂c∗t∂at

,

∂c∗t∂at

=r

1 + wλ.

Proposition 2. The household’s coefficient of absolute riskaversion in Proposition 1, evaluated at steady state, satisfies:

Ra(a; θ) =−V11(a; θ)

V1(a; θ)=−u11 + λu12

u1

r1 + wλ

.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Solve for Coefficient of Absolute Risk Aversion

V1(a; θ) = (1 + r) u1(c, l),

V11(a; θ) = (1 + r)

[u11(c, l)

∂c∗t∂at

+ u12(c, l)∂l∗t∂at

],

∂l∗t∂at

= −λ∂c∗t∂at

,

∂c∗t∂at

=r

1 + wλ.

Proposition 2. The household’s coefficient of absolute riskaversion in Proposition 1, evaluated at steady state, satisfies:

Ra(a; θ) =−V11(a; θ)

V1(a; θ)=−u11 + λu12

u1

r1 + wλ

.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Corollary 3.

Ra(a; θ) =−u11 + λu12

u1

r1 + wλ

≤ −u11

u1r .

If r < 1, then Ra(a; θ) is also less than −u11/u1.

Corollary 4. The household’s coefficient of absolute risk aversionis 0 if and only if the discriminant u11u22 − u2

12 = 0.

e.g.:

u(ct , lt ) =c1−γ

t1− γ

− η lt .

u(ct , lt ) = cθt (l − lt )1−θ.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Corollary 3.

Ra(a; θ) =−u11 + λu12

u1

r1 + wλ

≤ −u11

u1r .

If r < 1, then Ra(a; θ) is also less than −u11/u1.

Corollary 4. The household’s coefficient of absolute risk aversionis 0 if and only if the discriminant u11u22 − u2

12 = 0.

e.g.:

u(ct , lt ) =c1−γ

t1− γ

− η lt .

u(ct , lt ) = cθt (l − lt )1−θ.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Corollary 3.

Ra(a; θ) =−u11 + λu12

u1

r1 + wλ

≤ −u11

u1r .

If r < 1, then Ra(a; θ) is also less than −u11/u1.

Corollary 4. The household’s coefficient of absolute risk aversionis 0 if and only if the discriminant u11u22 − u2

12 = 0.

e.g.:

u(ct , lt ) =c1−γ

t1− γ

− η lt .

u(ct , lt ) = cθt (l − lt )1−θ.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Corollary 3.

Ra(a; θ) =−u11 + λu12

u1

r1 + wλ

≤ −u11

u1r .

If r < 1, then Ra(a; θ) is also less than −u11/u1.

Corollary 4. The household’s coefficient of absolute risk aversionis 0 if and only if the discriminant u11u22 − u2

12 = 0.

e.g.:

u(ct , lt ) =c1−γ

t1− γ

− η lt .

u(ct , lt ) = cθt (l − lt )1−θ.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Relative Risk Aversion

Consider Arrow-Pratt gamble of general size At :

at+1 = (1 + rt )at + wt lt + dt − ct + Atσεt+1,

vs.

at+1 = (1 + rt )at + wt lt + dt − ct − Atµ.

Risk aversion coefficient for this gamble:

−AtEtV11(a∗t+1; θt+1)

EtV1(a∗t+1; θt+1). (∗)

A natural benchmark for At is household wealth at time t .

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Relative Risk Aversion

Consider Arrow-Pratt gamble of general size At :

at+1 = (1 + rt )at + wt lt + dt − ct + Atσεt+1,

vs.

at+1 = (1 + rt )at + wt lt + dt − ct − Atµ.

Risk aversion coefficient for this gamble:

−AtEtV11(a∗t+1; θt+1)

EtV1(a∗t+1; θt+1). (∗)

A natural benchmark for At is household wealth at time t .

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Relative Risk Aversion

Consider Arrow-Pratt gamble of general size At :

at+1 = (1 + rt )at + wt lt + dt − ct + Atσεt+1,

vs.

at+1 = (1 + rt )at + wt lt + dt − ct − Atµ.

Risk aversion coefficient for this gamble:

−AtEtV11(a∗t+1; θt+1)

EtV1(a∗t+1; θt+1). (∗)

A natural benchmark for At is household wealth at time t .

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Household Wealth

In DSGE framework, household wealth has more than onecomponent:

financial assets at

present value of labor income, wt ltpresent value of net transfers, dt

present value of leisure, wt (l − lt )?

Leisure, in particular, can be hard to define, e.g.,

u(ct , lt ) =c1−γ

t1− γ

− ηl1+χt

1 + χ

and l is arbitrary.

Different definitions of household wealth lead to different definitionsof relative risk aversion.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Household Wealth

In DSGE framework, household wealth has more than onecomponent:

financial assets at

present value of labor income, wt ltpresent value of net transfers, dt

present value of leisure, wt (l − lt )?

Leisure, in particular, can be hard to define, e.g.,

u(ct , lt ) =c1−γ

t1− γ

− ηl1+χt

1 + χ

and l is arbitrary.

Different definitions of household wealth lead to different definitionsof relative risk aversion.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Household Wealth

In DSGE framework, household wealth has more than onecomponent:

financial assets at

present value of labor income, wt ltpresent value of net transfers, dt

present value of leisure, wt (l − lt )?

Leisure, in particular, can be hard to define, e.g.,

u(ct , lt ) =c1−γ

t1− γ

− ηl1+χt

1 + χ

and l is arbitrary.

Different definitions of household wealth lead to different definitionsof relative risk aversion.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Two Coefficients of Relative Risk Aversion

Definition 2. The consumption-wealth coefficient of relative riskaversion, Rc(at ; θt ), is given by (∗) withAt ≡ (1 + rt )

−1Et∑∞

τ=t mt ,τc∗τ .

In steady state:

Rc(a; θ) =−A V11(a; θ)

V1(a; θ)=−u11 + λu12

u1

c1 + wλ

.

Definition 3. The consumption-and-leisure-wealth coefficient ofrelative risk aversion, Rcl(at ; θt ), is given by (∗) with At ≡(1 + rt )

−1Et∑∞

τ=t mt ,τ(c∗τ + wτ (l − l∗τ )

).

In steady state:

Rcl(a; θ) =−A V11(a; θ)

V1(a; θ)=−u11 + λu12

u1

c + w (l − l)1 + wλ

.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Two Coefficients of Relative Risk Aversion

Definition 2. The consumption-wealth coefficient of relative riskaversion, Rc(at ; θt ), is given by (∗) withAt ≡ (1 + rt )

−1Et∑∞

τ=t mt ,τc∗τ .

In steady state:

Rc(a; θ) =−A V11(a; θ)

V1(a; θ)=−u11 + λu12

u1

c1 + wλ

.

Definition 3. The consumption-and-leisure-wealth coefficient ofrelative risk aversion, Rcl(at ; θt ), is given by (∗) with At ≡(1 + rt )

−1Et∑∞

τ=t mt ,τ(c∗τ + wτ (l − l∗τ )

).

In steady state:

Rcl(a; θ) =−A V11(a; θ)

V1(a; θ)=−u11 + λu12

u1

c + w (l − l)1 + wλ

.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Household with Generalized Recursive Preferences

Household chooses state-contingent {(ct , l t )} to maximize

V (at ; θt ) = max(ct ,lt )∈Γ(at ;θt )

u(ct , lt ) + β(

Et V (at+1; θt+1)1−α)1/(1−α)

Note: Generalized recursive preferences are often written as:

U(at ; θt ) = max(ct ,lt )∈Γ(at ;θt )

[u(ct , lt )ρ + β

(Et U(at+1; θt+1)α

)ρ/α]1/ρ

It’s easy to map back and forth from U to V ; moreover,V is more closely related to standard dynamic programmingresults, regularity conditions, and FOCsV makes derivations, formulas in the paper simpleradditively separable u is easier to consider in V

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Household with Generalized Recursive Preferences

Household chooses state-contingent {(ct , l t )} to maximize

V (at ; θt ) = max(ct ,lt )∈Γ(at ;θt )

u(ct , lt ) + β(

Et V (at+1; θt+1)1−α)1/(1−α)

Note: Generalized recursive preferences are often written as:

U(at ; θt ) = max(ct ,lt )∈Γ(at ;θt )

[u(ct , lt )ρ + β

(Et U(at+1; θt+1)α

)ρ/α]1/ρ

It’s easy to map back and forth from U to V ; moreover,V is more closely related to standard dynamic programmingresults, regularity conditions, and FOCsV makes derivations, formulas in the paper simpleradditively separable u is easier to consider in V

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Household with Generalized Recursive Preferences

Household chooses state-contingent {(ct , l t )} to maximize

V (at ; θt ) = max(ct ,lt )∈Γ(at ;θt )

u(ct , lt ) + β(

Et V (at+1; θt+1)1−α)1/(1−α)

Note: Generalized recursive preferences are often written as:

U(at ; θt ) = max(ct ,lt )∈Γ(at ;θt )

[u(ct , lt )ρ + β

(Et U(at+1; θt+1)α

)ρ/α]1/ρ

It’s easy to map back and forth from U to V ; moreover,V is more closely related to standard dynamic programmingresults, regularity conditions, and FOCsV makes derivations, formulas in the paper simpleradditively separable u is easier to consider in V

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Household with Generalized Recursive Preferences

Household chooses state-contingent {(ct , l t )} to maximize

V (at ; θt ) = max(ct ,lt )∈Γ(at ;θt )

u(ct , lt ) + β(

Et V (at+1; θt+1)1−α)1/(1−α)

subject to flow budget constraint

aτ+1 = (1 + rτ )aτ + wτ lτ + dτ − cτ

and No-Ponzi condition.

{wτ , rτ ,dτ} are exogenous processes, governed by θτ .

State variables of the household’s problem are (at ; θt ).

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Proposition 1. The household’s coefficient of absolute riskaversion at (at ; θt ), denoted Ra(at ; θt ), satisfies

−Et[V (a∗t+1; θt+1)−αV11(a∗t+1; θt+1)− αV (a∗t+1; θt+1)−α−1V1(a∗t+1; θt+1)2]

Et V (a∗t+1; θt+1)−αV1(a∗t+1; θt+1).

Evaluated at the nonstochastic steady state, this simplifies to:

Ra(a; θ) =−V11(a; θ)

V1(a; θ)+ α

V1(a; θ)

V (a; θ).

Proposition 3. The household’s coefficient of absolute riskaversion in Proposition 1, evaluated at steady state, satisfies:

Ra(a; θ) =−u11 + λu12

u1

r1 + wλ

+ αr u1

u.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Proposition 1. The household’s coefficient of absolute riskaversion at (at ; θt ), denoted Ra(at ; θt ), satisfies

−Et[V (a∗t+1; θt+1)−αV11(a∗t+1; θt+1)− αV (a∗t+1; θt+1)−α−1V1(a∗t+1; θt+1)2]

Et V (a∗t+1; θt+1)−αV1(a∗t+1; θt+1).

Evaluated at the nonstochastic steady state, this simplifies to:

Ra(a; θ) =−V11(a; θ)

V1(a; θ)+ α

V1(a; θ)

V (a; θ).

Proposition 3. The household’s coefficient of absolute riskaversion in Proposition 1, evaluated at steady state, satisfies:

Ra(a; θ) =−u11 + λu12

u1

r1 + wλ

+ αr u1

u.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Coefficient of Absolute Risk Aversion

Proposition 1. The household’s coefficient of absolute riskaversion at (at ; θt ), denoted Ra(at ; θt ), satisfies

−Et[V (a∗t+1; θt+1)−αV11(a∗t+1; θt+1)− αV (a∗t+1; θt+1)−α−1V1(a∗t+1; θt+1)2]

Et V (a∗t+1; θt+1)−αV1(a∗t+1; θt+1).

Evaluated at the nonstochastic steady state, this simplifies to:

Ra(a; θ) =−V11(a; θ)

V1(a; θ)+ α

V1(a; θ)

V (a; θ).

Proposition 3. The household’s coefficient of absolute riskaversion in Proposition 1, evaluated at steady state, satisfies:

Ra(a; θ) =−u11 + λu12

u1

r1 + wλ

+ αr u1

u.

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Asset Pricing

Expected excess return on asset i :

ψit ≡ Et r i

t+1 − r ft+1

= −Covt (mt+1, r it+1)

Proposition 7. To first order around the nonstochastic steadystate,

dmt+1 = −Ra(a; θ) dAt+1 + dΦt+1

To second order around the nonstochastic steady state,

ψit = Ra(a; θ) Covt (dr i

t+1,dAt+1) − Covt (dr it+1,dΦt+1)

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Asset Pricing

Expected excess return on asset i :

ψit ≡ Et r i

t+1 − r ft+1

= −Covt (mt+1, r it+1)

Proposition 7. To first order around the nonstochastic steadystate,

dmt+1 = −Ra(a; θ) dAt+1 + dΦt+1

To second order around the nonstochastic steady state,

ψit = Ra(a; θ) Covt (dr i

t+1,dAt+1) − Covt (dr it+1,dΦt+1)

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Numerical Example

Economy is a very simple, standard RBC model:

Competitive firms

Cobb-Douglas production, yt = Ztk1−ζt lζt

AR(1) technology, log Zt+1 = ρz log Zt + εt

Capital accumulation, kt+1 = (1− δ)kt + yt − ct

Equity is a consumption claim

Equity premium is expected excess return,

ψt =Et (Ct+1 + pt+1)

pt− (1 + r f

t )

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Numerical Example: Preferences

Period utility

u(ct , lt ) =c1−γ

t1− γ

− ηl1+χt

1 + χ

Generalized recursive preferences

V (at ; θt ) = max(ct ,lt )∈Γ(at ;θt )

u(ct , lt ) + β(

Et V (at+1; θt+1)1−α)1/(1−α)

Note:IES = 1/γIf labor fixed, relative risk aversion is Rfl = γ + α(1− γ)

If labor flexible, relative risk aversion is Rc , depends on χ, γ, α

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Numerical Example: Preferences

Period utility

u(ct , lt ) =c1−γ

t1− γ

− ηl1+χt

1 + χ

Generalized recursive preferences

V (at ; θt ) = max(ct ,lt )∈Γ(at ;θt )

u(ct , lt ) + β(

Et V (at+1; θt+1)1−α)1/(1−α)

Note:IES = 1/γIf labor fixed, relative risk aversion is Rfl = γ + α(1− γ)

If labor flexible, relative risk aversion is Rc , depends on χ, γ, α

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Additively Separable Period Utility

0

0.015

0.03

0.045

0.06

0.075

0.09

0.105

0.12

0.135

0.15

0

5

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40 45 50

Equity premium

 (percent per year)Coefficient of relative risk aversio

n

χ

Coefficient of relative risk aversion Rc (left axis)Equity premium

(right axis)

Fixed‐labor risk aversion measure, Rfl (left axis)

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Additively Separable Period Utility

0

0.02

0.04

0.06

0.08

0.1

0.12

0

5

10

15

20

25

30

0 10 20 30 40 50 60 70 80 90 100

Equity premium

 (percent per year)Coefficient of relative risk aversio

n

γ

Equity premium (right axis)

Coefficient of relative riskaversion Rc (left axis)

Fixed‐labor risk aversionmeasure, Rfl (left axis)

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Second Numerical Example

Same RBC model as before, with Cobb-Douglas period utility

u(ct , lt ) =

(cχt (1−lt )1−χ)1−γ

1− γ

and random-walk technology, ρz = 1.

Note:IES = 1/γIf labor fixed, risk aversion is Rfl =

(1− χ(1− γ)

)+ α(1− γ)

For composite good, risk aversion is Rcl = γ + α(1− γ)

Risk aversion Rc recognizes labor is flexible, excludes value ofleisure from household wealth, Rc = χγ + χα(1− γ)

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Cobb-Douglas Period Utility

0

0.04

0.08

0.12

0.16

0.2

0.24

0

2

4

6

8

10

12

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Equity premium

(percent per year)Coef

ficie

nt o

f Rel

ativ

e Ri

sk A

vers

ion

χ

Equity premium (right axis)

Coefficient of relative riskaversion Rc (left axis)

Fixed-labor risk aversion measure, Rfl (left axis)

Coefficient of relative risk aversion Rcl (left axis)

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Cobb-Douglas Period Utility

0

0.04

0.08

0.12

0.16

0.2

0.24

0

2

4

6

8

10

12

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Equity Premium

 (percent per year)Coefficient of R

elative Risk Aversion

γ

Equity premium (right axis)

Coefficient of relative riskaversion Rc (left axis)

Coefficient of relative riskaversion Rcl (left axis)

Fixed‐labor risk aversionmeasure, Rfl (left axis)

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Risk Neutrality

Hansen-Rogerson linear-labor preferences are common:

Extensive labor margin: Hansen (1985), Rogerson (1988)Monetary search: Lagos-Wright (2005)Investment: Khan-Thomas (2008), Bachmann-Caballero-Engel (2010), Bachmann-Bayer (2009)

These papers all effectively assume risk neutrality.

Risk neutrality is a desirable simplifying assumption in someapplications:

Labor search: Mortensen-Pissarides (1994)Financial frictions: Bernanke-Gertler-Gilchrist (1996, 1999)

The present paper suggests ways to model risk neutrality that donot require linear utility of consumption.

Page 73: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Risk Neutrality

Hansen-Rogerson linear-labor preferences are common:

Extensive labor margin: Hansen (1985), Rogerson (1988)Monetary search: Lagos-Wright (2005)Investment: Khan-Thomas (2008), Bachmann-Caballero-Engel (2010), Bachmann-Bayer (2009)

These papers all effectively assume risk neutrality.

Risk neutrality is a desirable simplifying assumption in someapplications:

Labor search: Mortensen-Pissarides (1994)Financial frictions: Bernanke-Gertler-Gilchrist (1996, 1999)

The present paper suggests ways to model risk neutrality that donot require linear utility of consumption.

Page 74: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Risk Neutrality

Hansen-Rogerson linear-labor preferences are common:

Extensive labor margin: Hansen (1985), Rogerson (1988)Monetary search: Lagos-Wright (2005)Investment: Khan-Thomas (2008), Bachmann-Caballero-Engel (2010), Bachmann-Bayer (2009)

These papers all effectively assume risk neutrality.

Risk neutrality is a desirable simplifying assumption in someapplications:

Labor search: Mortensen-Pissarides (1994)Financial frictions: Bernanke-Gertler-Gilchrist (1996, 1999)

The present paper suggests ways to model risk neutrality that donot require linear utility of consumption.

Page 75: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Risk Neutrality

Hansen-Rogerson linear-labor preferences are common:

Extensive labor margin: Hansen (1985), Rogerson (1988)Monetary search: Lagos-Wright (2005)Investment: Khan-Thomas (2008), Bachmann-Caballero-Engel (2010), Bachmann-Bayer (2009)

These papers all effectively assume risk neutrality.

Risk neutrality is a desirable simplifying assumption in someapplications:

Labor search: Mortensen-Pissarides (1994)Financial frictions: Bernanke-Gertler-Gilchrist (1996, 1999)

The present paper suggests ways to model risk neutrality that donot require linear utility of consumption.

Page 76: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Empirical Estimates of Risk Aversion

Barsky-Juster-Kimball-Shaprio (1997):

“Suppose that you are the only income earner in the family, andyou have a good job guaranteed to give you your current (fam-ily) income every year for life. You are given the opportunity totake a new and equally good job, with a 50–50 chance it willdouble your (family) income and a 50–50 chance that it will cutyour (family) income by a third. Would you take the new job?”

Empirical estimates of risk aversion using methods like theseremain generally valid in the framework of the present paper, butshould be phrased more carefully.

What is different is how these estimates are mapped into modelparameters (i.e., risk aversion 6= −cu11/u1)

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Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Empirical Estimates of Risk Aversion

Barsky-Juster-Kimball-Shaprio (1997):

“Suppose that you are the only income earner in the family, andyou have a good job guaranteed to give you your current (fam-ily) income every year for life. You are given the opportunity totake a new and equally good job, with a 50–50 chance it willdouble your (family) income and a 50–50 chance that it will cutyour (family) income by a third. Would you take the new job?”

Empirical estimates of risk aversion using methods like theseremain generally valid in the framework of the present paper, butshould be phrased more carefully.

What is different is how these estimates are mapped into modelparameters (i.e., risk aversion 6= −cu11/u1)

Page 78: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Empirical Asset Pricing

Campbell (1996, 1999): u(Ct ) =C1−γ

t1− γ

, mt+1 = logβ − γ∆ct+1

Et (ri,t − rf ,t ) = γ Cov(ri,t+1,∆ct+1)

Country Et (re,t − rf ,t ) std(re,t − rf ,t ) std(∆c) γ

USA 5.82 17.0 0.91 37.3JPN 6.83 21.6 2.35 13.4GER 6.77 20.4 2.50 13.3FRA 7.12 22.8 2.13 14.6UK 8.31 21.6 2.59 14.9ITA 2.17 27.3 1.68 4.7

CAN 3.04 16.7 2.03 9.0

If u(Ct ) =C1−γ

t1− γ

− ηL1+χ

t1 + χ

, then γ 6= risk aversion.

Page 79: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Empirical Asset Pricing

Campbell (1996, 1999): u(Ct ) =C1−γ

t1− γ

, mt+1 = logβ − γ∆ct+1

Et (ri,t − rf ,t ) = γ Cov(ri,t+1,∆ct+1)

Country Et (re,t − rf ,t ) std(re,t − rf ,t ) std(∆c) γ

USA 5.82 17.0 0.91 37.3JPN 6.83 21.6 2.35 13.4GER 6.77 20.4 2.50 13.3FRA 7.12 22.8 2.13 14.6UK 8.31 21.6 2.59 14.9ITA 2.17 27.3 1.68 4.7

CAN 3.04 16.7 2.03 9.0

If u(Ct ) =C1−γ

t1− γ

− ηL1+χ

t1 + χ

, then γ 6= risk aversion.

Page 80: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Empirical Asset Pricing

Campbell (1996, 1999): u(Ct ) =C1−γ

t1− γ

, mt+1 = logβ − γ∆ct+1

Et (ri,t − rf ,t ) = γ Cov(ri,t+1,∆ct+1)

Country Et (re,t − rf ,t ) std(re,t − rf ,t ) std(∆c) γ

USA 5.82 17.0 0.91 37.3JPN 6.83 21.6 2.35 13.4GER 6.77 20.4 2.50 13.3FRA 7.12 22.8 2.13 14.6UK 8.31 21.6 2.59 14.9ITA 2.17 27.3 1.68 4.7

CAN 3.04 16.7 2.03 9.0

If u(Ct ) =C1−γ

t1− γ

− ηL1+χ

t1 + χ

, then γ 6= risk aversion.

Page 81: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Empirical Asset Pricing

Campbell (1996, 1999): u(Ct ) =C1−γ

t1− γ

, mt+1 = logβ − γ∆ct+1

Et (ri,t − rf ,t ) = γ Cov(ri,t+1,∆ct+1)

Country Et (re,t − rf ,t ) std(re,t − rf ,t ) std(∆c) γ

USA 5.82 17.0 0.91 37.3JPN 6.83 21.6 2.35 13.4GER 6.77 20.4 2.50 13.3FRA 7.12 22.8 2.13 14.6UK 8.31 21.6 2.59 14.9ITA 2.17 27.3 1.68 4.7

CAN 3.04 16.7 2.03 9.0

If u(Ct ) =C1−γ

t1− γ

− ηL1+χ

t1 + χ

, then γ 6= risk aversion.

Page 82: Risk Aversion, Risk Premia, and the Labor Margin with ...swanson2/pres/birkbeck2013crra.pdfRisk Aversion, Risk Premia, and the Labor Margin with Generalized Recursive Preferences Eric

Introduction Framework Absolute RA Relative RA EZ Preferences Asset Pricing Conclusions

Conclusions

1 A flexible labor margin affects risk aversion2 Risk premia are related to risk aversion3 Fixed-labor measure of risk aversion performs poorly4 Composite-good measure of risk aversion also seems to

perform poorly5 For multiplier preferences, risk aversion is very sensitive to

scaling by (1− β)

6 Simple, closed-form expressions for risk aversion with:flexible labor margingeneralized recursive preferencesexternal or internal habitsvalidity away from steady statecorrespondence to risk premia in the model

7 New paper: frictional labor markets