Appendix to “Long-Run Risk, the Wealth-Consumption Ratio, and the Temporal Pricing of Risk” By Ralph S.J. Koijen, Hanno Lustig, Stijn Van Nieuwerburgh and Adrien Verdelhan ∗ In this appendix, we first derive four risk premia: the expected excess returns on a consumption claim, on equity and on real and nominal bonds. We then obtain the Alvarez and Jermann (2005) decomposition of the SDF in the long-run risk model. We present the parameter values used in our calibration and our simulation results. Finally, we report robustness checks and empirical variance ratios. ∗ Koijen: The University of Chicago Booth School of Business 5807 South Woodlawn Avenue, Chicago, IL 60637; [email protected]. Lustig: Anderson School of Management, University of California at Los Angeles, Box 951477, Los Angeles, CA 90095; [email protected]. Van Nieuwerburgh: Department of Finance, Stern School of Business, New York University, 44 W. 4th Street, New York, NY 10012; [email protected]. Verdelhan: Department of Finance, MIT Sloan School of Management and Bank of France, E52-436, 50 Memorial Drive, Cambridge, MA 02142; [email protected]. We thank Rustom Irani for excellent research assistance and Ravi Bansal, Jaroslav Borovicka, Mike Chernov, Itamar Drechsler, John Heaton, Lars Hansen, Jose Scheinkman, Ivan Shaliastovich and George Tauchen for comments. 1 2 THE AMERICAN ECONOMIC REVIEW I. MAY 2010 Wealth-Consumption Ratio and Consumption Risk Premium We start from the aggregate budget constraint: c Wt+1 = Rt+1 (Wt − Ct ). (1) The beginning-of-period (or cum-dividend) total wealth Wt that is not spent on aggregate c consumption Ct earns a gross return Rt+1 and leads to beginning-of-next-period total wealth Wt+1 . The return on a claim to aggregate consumption, the total wealth return, can be written as Wt+1 Ct+1 W Ct+1 c = Rt+1 = . Wt − Ct Ct W Ct − 1 We use the Campbell (1991) approximation of the log total wealth return rtc = log(Rtc ) around the long-run average log wealth-consumption ratio µwc ≡ E[wt − ct ]: c rt+1 = κc0 + ∆ct+1 + wct+1 − κc1 wct , where the linearization constants κc0 and κc1 are non-linear functions of the unconditional mean log wealth-consumption ratio µwc : κc1 = eµwc eµwc > 1 and κc0 = − log (eµwc − 1) + µwc µwc . −1 e −1 eµwc Throughout the paper, we use lower letters to denote logs. The Euler equation for any asset i with lognormal return Ri implies: (2) i 1 i 1 i 0 = Et [sdft+1 ] + Et rt+1 + Vart [sdft+1 ] + Vart rt+1 + Covt sdft+1 , rt+1 2 2 2 We conjecture that the wealth-consumption ratio is linear in the state variables xt , σgt 2 and σxt : 2 2 wct = µwc + Wx xt + Wgs σgt − σg2 + Wxs σxt − σx2 We first compute the different components of equation 2: c rt+1 = c Et rt+1 = c c rt+1 − Et rt+1 = c Vt rt+1 = r0c = 2 2 r0c + [1 + Wx (ρ − κc1 )] xt + Wgs (νg − κc1 ) σgt − σg2 + Wxs (νx − κc1 ) σxt − σx2 + σgt ηt+1 + Wx σxt et+1 + Wgs σgw wg,t+1 + Wxs σxw wx,t+1 2 2 − σx2 r0 + [1 + Wx (ρ − κc1 )] xt + Wgs (νg − κc1 ) σgt − σg2 + Wxs (νx − κc1 ) σxt σgt ηt+1 + Wx σxt et+1 + Wgs σgw wg,t+1 + Wxs σxw wx,t+1 2 2 2 2 2 2 σgt + Wx2 σxt + Wgs σgw + Wxs σxw κc0 + µg + (1 − κc1 ) µwc VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO 3 Epstein and Zin (1989) show that the log real stochastic discount factor is sdft+1 = = sdft+1 − Et [sdft+1 ] = Et [sdft+1 ] = Vt [sdft+1 ] = µs c Covt rt+1 , sdft+1 = θ c θ log δ − ∆ct+1 + (θ − 1) rt+1 ψ θ µs + − + (θ − 1) [1 + Wx (ρ − κc1 )] xt ψ 2 2 + {Wgs (νg − κc1 ) (θ − 1)} σgt − σg2 + {Wxs (νx − κc1 ) (θ − 1)} σxt − σx2 1 + θ 1− − 1 σgt ηt+1 + (θ − 1) {Wx σxt et+1 + Wgs σgw wg,t+1 + Wxs σxw wx,t+1 } ψ 1 − 1 σgt ηt+1 + (θ − 1) {Wx σxt et+1 + Wgs σgw wg,t+1 + Wxs σxw wx,t+1 } θ 1− ψ θ µs + − + (θ − 1) [1 + Wx (ρ − κc1 )] xt ψ 2 2 + {Wgs (νg − κc1 ) (θ − 1)} σgt − σg2 + {Wxs (νx − κc1 ) (θ − 1)} σxt − σx2 2 1 2 2 2 2 2 2 2 − 1 σgt + (θ − 1) Wx2 σxt + Wgs σgw + Wxs σxw θ 1− ψ θ θ log δ − µg + (θ − 1) r0c ψ c c = Et (rt+1 − Et rt+1 )(sdft+1 − Et [sdft+1 ]) 1 2 2 2 2 2 2 = θ 1− − 1 σgt + Wx2 (θ − 1) σxt + Wgs (θ − 1) σgw + Wxs (θ − 1) σxw ψ Plugging these different components into equation (2) evaluated at i = c yields: ( ) 2 θ2 1 c 2 2 2 2 2 2 2 (3) 0 = r0 + µs + 1− σg + Wx σx + Wgs σgw + Wxs σxw 2 ψ 1 c (4) +θ − + [1 + Wx (ρ − κ1 )] xt ψ ( 2 ) θ 1 c 2 (5) + 2Wgs (νg − κ1 ) + θ 1 − σgt − σg2 2 ψ (6) + 2 θ 2Wxs (νx − κc1 ) + θWx2 σxt − σx2 2 4 THE AMERICAN ECONOMIC REVIEW MAY 2010 Then setting all coefficients equal to zero we obtain: (4) =⇒ Wx = (5) =⇒ Wgs = (6) =⇒ Wxs 1− 1 ψ κc1 − ρ θ 1− 1 ψ 2 2 (κc1 − νg ) θ = 2 (κc1 − νx ) 1− 1 ψ κc1 − ρ !2 If the IES exceeds 1, then Wx > 0, Wgs < 0, and Wxs < 0. Plugging these coefficients back into equation (3) implicitly defines a nonlinear equation in one unknown (µwc ), which can be solved for numerically, characterizing the average wealth-consumption ratio. According to (2), the risk premium (expected excess real return corrected for a Jensen term) on the consumption claim is given by1 : c,e c , sdft+1 Et rt+1 = −Covt rt+1 1 2 2 2 2 2 2 = 1−θ 1− σgt + Wx2 (1 − θ) σxt + Wgs (1 − θ) σgw + Wxs (1 − θ) σxw ψ = 2 2 2 2 λη σgt + Wx λe σxt + Wgs λgw σgw + Wxs λxw σxw with the market price of risk vector Λ = [λη , λe , λgw , λxw ] given by: λη = 1 − θ 1− −1 = γ >0 ψ λe = (1 − θ) Wx = λgw = (1 − θ) Wgs = − λxw = γ− 1 ψ κc1 − ρ (1 − θ) Wxs = − (γ − 1) (γ − 1 ψ) 2 (κc1 − νg ) (γ − 1) (γ − 1 ψ) 2 (κc1 − νx ) (κc1 − ρ)2 If the IES is sufficiently large (γ > 1/ψ), then λe > 0, λgw < 0, and λxw < 0. II. Equity Risk Premium We log-linearize return on portfolio: rt+1 = κ0 + ∆dt+1 + pdt+1 − κ1 pdt , and conjecture that the price-dividend ratio is linear in the state variables: pdt = µpd + Dx xt + 2 2 Dgs σgt − σg2 + Dxs σxt − σx2 As we did for the return on the consumption claim, we compute innovations in the 1 Recall that the log riskfree rate is yt (1) = −Et [sdft+1 ] − 12 Vart [sdft+1 ]. VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO 5 dividend claim return, and its conditional mean and variance: rt+1 = rt+1 − Et [rt+1 ] = Et [rt+1 ] = Vart [rt+1 ] = r0 = 2 2 r0 + {φx + Dx (ρ − κ1 )} xt + Dgs (νg − κ1 ) σgt − σg2 + Dxs (νx − κ1 ) σxt − σx2 +ϕd σgt ηd,t+1 + Dx σxt et+1 + Dgs σgw wg,t+1 + Dxs σxw wx,t+1 ϕd σgt ηd,t+1 + Dx σxt et+1 + Dgs σgw wg,t+1 + Dxs σxw wx,t+1 2 r0 + {φx + Dx (ρ − κ1 )} xt + Dgs (νg − κ1 ) σgt − σg2 2 +Dxs (νx − κ1 ) σxt − σx2 2 2 2 2 2 2 ϕ2d σgt + Dx2 σxt + Dgs σgw + Dxs σxw κ0 + µpd (1 − κ1 ) + µd 2 2 2 2 Covt [rt+1 , sdft+1 ] = (θ − 1) Wgs Dgs σgw + Wxs Dxs σxw − γϕd τgd σgt + (θ − 1) Wx Dx σxt Plug these different components into equation (2): 0 = µs + r0 + 1 2 1 1 2 γ − 2γϕd τdg + ϕ2d σg2 + [Wx (θ − 1) + Dx ]2 σx2 + [Wgs (θ − 1) + Dgs ]2 σgw 2 2 2 1 2 2 + (7) [Wxs (θ − 1) + Dxs ] σxw 2 1 + (8) − + [φx + Dx (ρ − κ1 )] xt ψ 1 2 2 + (9) γ − 2γϕd τdg + ϕ2d + Wgs (κc1 − νg ) (1 − θ) + Dgs (νg − κ1 ) σgt − σg2 2 1 2 2 + (10)[Wx (θ − 1) + Dx ] + Wxs (κc1 − νx ) (1 − θ) + Dxs (νx − κ1 ) σxt − σx2 2 Then setting all coefficients equal to zero we get: (8) (9) =⇒ Dx = =⇒ Dgs = φx − κ1 − ρ 2 1 2 2 γ − 2γϕd τdg + ϕd − κ1 − νg 1 2 (10) =⇒ Dxs = 1 ψ hφ 1 x− ψ κ1 −ρ − 1 i2 γ− ψ c κ1 −ρ − 1 2 γ− 1 ψ (γ − 1) 1 1 (γ−1)(γ− ψ ) c −ρ 2 2 κ ( 1 ) κ1 − νx Plugging these into (7) implicitly defines a nonlinear equation in one unknown (i.e., µpd ), which can be solved for numerically, characterizing the mean price-dividend ratio. The D coefficients are the betas of the equity market portfolio with respect to the four fundamental consumption growth shocks. 6 THE AMERICAN ECONOMIC REVIEW MAY 2010 The equity risk premium is equal to: e Et rt+1 = −Covt [rt+1 , sdft+1 ] G0 Ggs Gxs 2 2 2 2 = (ϕd τgd ) λη σgt + Dx λe σxt + Dgs λgw σgw + Dxs λxw σxw 2 2 = G0 + Ggs σg2 + Gxs σx2 + Ggs σgt − σg2 + Gxs σxt − σx2 2 2 = Dgs λgw σgw + Dxs λxw σxw = ϕd τgd γ = Dx λe III. Real Bond Returns and Risk Premium We start off the expression for the real stochastic discount factor derived in the first sub-section above. Let define the following three parameters: sx ≡ − ψ1 , sgs ≡ − 12 (γ − 1 1)(γ − ψ1 ), and sxs ≡ − 21 (γ − 1)(γ − ψ1 ) (κc −ρ) 2 . Using notation defined above and in the 1 previous sub-sections, the real stochastic discount factor is: 2 2 sdft+1 = µs + sx xt + sgs σgt − σg2 + sxs σxt − σx2 −λη σgt ηt+1 − λe σxt et+1 − λgw σgw wg,t+1 − λxw σxw wx,t+1 Let pbt (n) = log Ptb (n) be the log price and ytb (n) = − n1 pbt (n) the yield of an n-period real bond. We conjecture that the log prices of real linear in the state variables: pt (n) = bonds are 2 2 −B0 (n) − Bx (n)xt − Bgs (n) σgt − σg2 − Bxs σxt − σx2 The coefficients are initialized at zero and satisfy the following recursions: B0 (n) Bx (n) Bgs (n) Bxs (n) 1 2 2 = B0 (n − 1) − µs − [λgw + Bgs (n − 1)] σgw 2 o 1n 2 2 − [λxw + Bxs (n − 1)] σxw + λ2η σg2 2 1 2 − [λe + Bx (n − 1)] σx2 2 1 = ρBx (n − 1) + ψ 1 1 1 = νg Bgs (n − 1) + (γ − 1)(γ − ) − γ 2 2 ψ 2 " #2 1 1 (γ − ψ ) 1 1 γ−ψ = νx Bxs (n − 1) + (γ − 1) c − + Bx (n − 1) . 2 (κ1 − ρ)2 2 κc1 − ρ VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO 7 These recursions imply the following limit values: Bx (∞) = Bgs (∞) = Bxs (∞) = 1 ψ(1 − ρ) 1 2 (γ − 1)(γ − 1 ψ) − 12 γ 2 1 − νg 1 2 (γ (γ− 1 ) ψ − 1) (κc −ρ) 2 − 1 1 2 h γ− 1 ψ κc1 −ρ 1 − νx i2 + Bx (∞) . We define B(∞) ≡ [Bx (∞), Bgs (∞), Bxs (∞)]′ . The real bond risk premium on monthly holding period returns is equal to: b rt+1 (n) ≡ b b rt+1 (n) − Et rt+1 (n) = h i b,e Et rt+1 (n) = = F0 (n) = Fgs (n) = Fxs (n) = b nytb (n) − (n − 1)yt+1 (n − 1) −Bx (n − 1)σxt et+1 − Bgs (n − 1)σgw wg,t+1 −Bxs (n − 1)σxw wx,t+1 b −Covt rt+1 , sdft+1 2 2 F0 (n) + Fgs (n)σg2 + Fxs (n)σx2 + Fgs (n) σgt − σg2 + Fxs (n) σxt − σx2 2 2 −Bgs (n − 1)λgw σgw − Bxs (n − 1)λxw σxw , 0, −Bx (n − 1)λe . We now define some vectors and matrices to present results in a more compact way. 2 2 Let the vector Xt summarize all real state variables: Xt ≡ [xt , σgt − σg2 , σxt − σx2 ]′ . Let εt+1 denote the corresponding gaussian, i.i.d shocks: εt+1 ≡ [et+1 , wg,t+1 , wx,t+1 ]′ . 2 2 2 We define Σt ≡ diag[σxt , σgw , σxw ]. The law of motion of the state vector Xt is Xt+1 = 1 ΓXt + Σt2 εt+1 , where Γ is a 3 by 3 diagonal matrix with ρ, ϕzg , and ϕzx on the diagonal. Let B(n) denote all the n-period real bond parameters: B(n) ≡ [Bx (n), Bgs (n), Bxs (n)]′ . Using this notation, we can rewrite the real bond risk premium as: h i b,e Et rt+1 (n) = −B(n − 1)′ Σt Λ. IV. Nominal Bond Returns and Risk Premium We start off the expression for the real stochastic discount factor derived above. We use a $ superscript to denote nominal variables. The nominal stochastic discount factor is then: $ sdft+1 ≡ = sdft+1 − πt+1 2 2 − σx2 − (π̄t − µπ ) µs − µπ + sx xt + sgs σgt − σg2 + sxs σxt − (λη + ϕπg ) σgt ηt+1 − (λe + ϕπx ) σxt et+1 − λgw σgw wg,t+1 − λxw σxw wx,t+1 − σπ ξt+1 Let p$t (n) = log Pt$ (n) be the log price and yt$ (n) = − n1 p$t (n) the yield of an n-period 8 THE AMERICAN ECONOMIC REVIEW MAY 2010 nominal bond. We conjecture that the log prices of nominal bonds are linear in the state variables: $ 2 $ 2 p$t (n) = −B0$ (n) − Bx$ (n)xt − Bgs (n) σgt − σg2 − Bxs σxt − σx2 − Bπ$ (n) (π̄t − µπ ) The coefficients are initialized at zero and satisfy the following recursions: i2 h i2 1 h $ $ $ $ 2 σπ + Bπ (n − 1)σz + λgw + Bgs (n − 1) σgw B0 (n) = B0 (n − 1) − µs + µπ − 2 h i2 h i2 1 $ 2 $ − λxw + Bxs (n − 1) σxw + ϕπg + λη + ϕzg Bπ (n − 1) σg2 2 i2 1h − ϕπx + λe + Bx$ (n − 1) + ϕzx Bπ$ (n − 1) σx2 2 Bx$ (n) = ρBx$ (n − 1) + αx Bπ$ (n − 1) − sx i2 1h $ $ Bgs (n) = νg Bgs (n − 1) − sgs − λη + ϕπg + ϕzg Bπ$ (n − 1) 2 i2 1h $ $ λe + ϕπx + Bx$ (n − 1) + ϕzx Bπ$ (n − 1) Bxs (n) = νx Bxs (n − 1) − sxs − 2 $ $ Bπ (n) = απ Bπ (n − 1) + 1. These recursions imply the following limit values: Bx$ (∞) = $ Bgs (∞) = $ Bxs (∞) = Bπ$ (∞) = αx Bπ$ (∞) − sx 1−ρ 2 −sgs − 12 λη + ϕπg + ϕzg Bπ$ (∞) 1 − νg 2 1 −sxs − 2 λe + ϕπx + Bx$ (∞) + ϕzx Bπ$ (∞) 1 − νx 1 . 1 − απ $ $ We define B $ (∞) ≡ [Bx$ (∞), Bgs (∞), Bxs (∞), Bπ$ (∞)]′ . The nominal bond risk premium on monthly holding period returns is equal to: b,$ rt+1 (n) ≡ h i b,$ b,$ rt+1 (n) − Et rt+1 (n) = h i b,$,e Et rt+1 (n) = = F0$ (n) = $ Fgs (n) = $ Fxs (n) = $ nyt$ (n) − (n − 1)yt+1 (n − 1) $ − Bx$ (n − 1) + Bπ$ (n − 1)ϕzx σxt et+1 − Bgs (n − 1)σgw wg,t+1 $ −Bxs (n − 1)σxw wx,t+1 − Bπ$ (n − 1) (ϕzg σgt ηt+1 + σz ξt+1 ) h i b,$ $ −Covt rt+1 , sdft+1 i h 2 $ 2 $ $ $ − σx2 − σg2 + Fxs (n) σxt (n)σg2 + Fxs (n)σx2 + Fgs (n) σgt F0$ (n) + Fgs o n $ 2 $ 2 − λgw Bgs (n − 1)σgw + λxw Bxs (n − 1)σxw + σπ σz Bπ$ (n − 1) − (λη + ϕπg ) ϕzg Bπ$ (n − 1) − (λe + ϕπx ) Bx$ (n − 1) + Bπ$ (n − 1)ϕzx VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO 9 Define the following vector and matrix objects: b$ b$ Λ B (n) bt Σ εbt+1 ≡ [λη + ϕπg , λe + ϕπx , λgw , λxw , σπ ], $ $ (n), Bπ$ (n)σz ], ≡ [Bπ$ (n)ϕzg , Bx$ (n) + Bπ$ (n)ϕzx , Bgs (n), Bxs 2 2 2 2 ≡ diag[σgt , σxt , σgw , σxw , 1], ≡ [ηt+1 , et+1 , wg,t+1 , wx,t+1 , ξt+1 ] Then we can write the nominal bond risk premium compactly as: h i b,$,e b $′ (n − 1)Σ b tΛ b $. Et rt+1 (n) = −B V. Decomposition of the Real SDF The following proposition shows how to decompose the SDF of the long-run risk model into a martingale component and the dominant pricing component. Proposition 1. The stochastic discount factor of the long-run risk model can be decomposed into a martingale component and the dominant pricing component: T Mt+1 MtT P Mt+1 MtP = = 1 ′ ′ β exp −B∞ (I − Γ) Xt + B∞ Σt2 εt+1 , 1 ′ ′ β −1 exp µs + [S ′ + B∞ (I − Γ)] Xt − (Λ′ + B∞ ) Σt2 εt+1 − λη σgt ηt+1 . To show this, we start from the definition of the dominant pricing component of the pricing kernel: β t+n MtT = lim b , n→∞ P (n) t Recall that log real bond prices are affine in the state vector: 2 2 pbt (n) = −B0 (n) − Bx (n)xt − Bgs (n) σgt − σg2 − Bxs σxt − σx2 = −B0 (n) − B(n)′ Xt . We can then write the dominant pricing component of the SDF as: MtT = lim β t+n exp (B0 (n) + B(n)′ Xt ) . n→∞ The constant β is chosen in order to satisfy Assumption 1 in Alvarez and Jermann (2005): P b (n) 0 < lim t n < ∞. n→∞ β Recall that B0 (n) is defined recursively: B0 (n) = − o 1n 2 2 B0 (n − 1) − µs − [λgw + Bgs (n − 1)] σgw 2 o 1n 2 2 2 [λxw + Bxs (n − 1)] σxw + λ2η σg2 + [λe + Bx (n − 1)] σx2 2 10 THE AMERICAN ECONOMIC REVIEW MAY 2010 Because of the affine term structure of the model and the stationarity of the state vector X, the limit limn→∞ B(n) = B(∞) is finite. Taking limits on both sides of the equation above leads to: o 1n 2 2 lim B0 (n) − B0 (n − 1) = −µs − [λgw + Bgs (∞)] σgw n→∞ 2 o 1n 2 2 2 − [λxw + Bxs (∞)] σxw + λ2η σg2 + [λe + Bx (∞)] σx2 2 The limit of B0 (n) − B0 (n − 1) is finite, so that B0 (n) grows at a linear rate in the limit. We choose the constant β to offset the growth in B0 (n) as n becomes very large. Setting o 1n 2 2 2 2 2 β = exp µs + [λgw + Bgs (∞)] σgw + [λxw + Bxs (∞)] σxw + λ2η σg2 + [λe + Bx (∞)] σx2 2 guarantees that Assumption 1 in Alvarez and Jermann (2005) is satisfied. We can now write the dominant pricing component of the SDF as: T 1 Mt+1 ′ ′ 2 = β exp −B (I − Γ) X + B Σ ε , t t+1 ∞ ∞ t MtT To derive the martingale component of the SDF, let us go back to the SDF itself. Let S and Λ denote the parameters of the real SDF: S ≡ [sx , sgs , sxs ]′ , Λ ≡ [λe , λgw , λxw ]′ . Then the real SDF is: 1 Mt+1 SDFt+1 = = exp µs + S ′ Xt − Λ′ Σt2 εt+1 − λη σgt ηt+1 . Mt As a result, the martingale component of the SDF is: P Mt+1 MtP = = 1. T −1 Mt+1 MT t 1 ′ ′ β −1 exp µs + [S ′ + B∞ (I − Γ)] Xt − (Λ′ + B∞ ) Σt2 εt+1 − λη σgt ηt+1 . Mt+1 Mt P We need to verify that the martingale component is a martingale, i.e that Et [Mt+1 /MtP ] = To do this, recall that the bond parameters evolve as: Bx (n) Bgs (n) Bxs (n) = ρBx (n − 1) − sx 1 = νg Bgs (n − 1) − sgs − λ2η 2 1 = νx Bxs (n − 1) − sxs − [λe + Bx (n − 1)]2 . 2 Taking limits as n → ∞ leads to: 1 1 2 B(∞)′ (I − Γ) = −S ′ + [0, − λ2η , − [λe + Bx (∞)] ]′ . 2 2 VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO 11 To check the martingale condition, plug the definition of β in the following expression: Et P Mt+1 MtP = β −1 1 ′ 1 2 2 ′ ′ ′ exp µs + [S + B∞ (I − Γ)] Xt + (Λ + B∞ ) Σt (Λ + B∞ ) + λη σgt . 2 2 The term in front of Xt is equal to [0, − 12 λ2η , − 1 2 2 2 [λe + Bx (∞)] ]′ . Terms in σgt and 2 σxt cancel out. We next plug in the expression for β and check that Et [ P Mt+1 ] MtP = 1. We now turn to the conditional variances of the log SDF and its dominant pricing and T P ] and Vart [sdft+1 ]. martingale components, Vart [sdft+1 ], Vart [sdft+1 2 Vart [sdft+1 ] = Λ′ Σt Λ + λ2η σgt T ′ Vart [sdft+1 ] = B∞ Σt B∞ P ′ 2 Vart [sdft+1 ] = (Λ′ + B∞ )Σt (Λ + B∞ ) + λ2η σgt . P The conditional variance ratio Vart [sdft+1 ]/Vt [sdft+1 ] equals ′ ′ P −B∞ Σt Λ − 12 B∞ Σt B∞ Vt [sdft+1 ] =1− 1 1 2 ′ 2 Vt [sdft+1 ] 2 Λ Σt Λ + 2 λη σgt ′ The first term in the numerator corresponds to the bond risk premium (−B∞ Σt Λ). 1 ′ It includes the Jensen term ( 2 B∞ Σt B∞ ). As a result, the numerator corresponds to the bond risk premium without the Jensen term. The denominator corresponds to the maximum risk premium (also without the Jensen term). Note that the maximal Sharpe ratio in the model is: M axSRt = = = VI. σt (log SDFt+1 ) q 2 + λ2 σ 2 + λ2 σ 2 + λ2 σ 2 λ2e σxt gw gw xw xw η gt 1 2 2 Λ′ Σt Λ + λ2η σgt Decomposition of the Nominal SDF The following proposition shows how to decompose the nominal SDF of the long-run risk model into a martingale and a dominant pricing component. To avoid confusion, we use M N to denote the nominal pricing kernel. Proposition 2. The stochastic discount factor of the long-run risk model can be decomposed into a martingale component and the dominant pricing component: T M Nt+1 M NtT P M Nt+1 M NtP = = 1 $′ b $′ Σ b 2 bt+1 , β̃ exp −B∞ (I − Γ̃)X̃t + B ∞ t ε h i 1 $′ $ ′b 2 b$ + B b∞ β̃ −1 exp µs − µπ + S̃ ′ + B∞ I − Γ̃ X̃t − (Λ ) Σt εbt+1 . To show this, we start from the definition of the dominant pricing component of the 12 THE AMERICAN ECONOMIC REVIEW MAY 2010 pricing kernel: β̃ t+n , n→∞ P $b (n) t M NtT = lim Recall that log real bond prices are affine in the state vector: p$b t (n) $ 2 $ 2 = −B0$ (n) − Bx$ (n)xt − Bgs (n) σgt − σg2 − Bxs σxt − σx2 − Bπ$ (π̄t − µπ ) = −B0$ (n) − B $ (n)′ X̃t , 2 2 where we define X̃t = [xt , σgt − σg2 , σxt − σx2 , π̄t − µπ ]. We can then write the dominant pricing component of the SDF as: M NtT = lim β̃ t+n exp B0$ (n) + B $ (n)′ X̃t . n→∞ The constant β̃ is chosen in order to satisfy Assumption 1 in Alvarez and Jermann (2005): P $b (n) 0 < lim t n < ∞. n→∞ β Recall that B0$ (n) is defined recursively: B0$ (n) i2 h i2 1 h $ 2 = B0$ (n − 1) − µs + µπ − σπ + Bπ$ (n − 1)σz + λgw + Bgs (n − 1) σgw 2 i2 h i2 1 h $ 2 − λxw + Bxs (n − 1) σxw + ϕπg + λη + ϕzg Bπ$ (n − 1) σg2 2 i2 1h − ϕπx + λe + Bx$ (n − 1) + ϕzx Bπ$ (n − 1) σx2 2 Because of the affine term structure of the model and the stationarity of the state vector X̃, the limit limn→∞ B $ (n) ≡ B $ (∞) is finite. Taking limits on both sides of the equation above leads to: i2 h i2 1 h $ 2 lim B0$ (n) − B0$ (n − 1) = −µs + µπ − σπ + Bπ$ (∞)σz + λgw + Bgs (∞) σgw n→∞ 2 h i2 h i2 1 $ 2 − λxw + Bxs (∞) σxw + ϕπg + λη + ϕzg Bπ$ (∞) σg2 2 i2 1h − ϕπx + λe + Bx$ (∞) + ϕzx Bπ$ (∞) σx2 2 The limit of B0$ (n) − B0$ (n − 1) is finite, so that B0$ (n) grows at a linear rate in the limit. We choose the constant β̃ to offset the growth in B0$ (n) as n becomes very large. VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO 13 Setting β̃ = i2 h i2 1 h $ 2 exp µs − µπ + σπ + Bπ$ (∞)σz + λgw + Bgs (∞) σgw 2 h i2 h i2 1 $ 2 + λxw + Bxs (∞) σxw + ϕπg + λη + ϕzg Bπ$ (∞) σg2 2 i2 1h + ϕπx + λe + Bx$ (∞) + ϕzx Bπ$ (∞) σx2 2 guarantees that Assumption 1 in Alvarez and Jermann (2005) is satisfied. We can now write the dominant pricing component of the SDF as: T M Nt+1 M NtT = = where $′ β̃ exp −B∞ (I − Γ̃)X̃t + Bπ$ (∞)ϕzg σgt ηt+1 + Bπ$ (∞)σz ξt+1 $ $ +[Bx$ (∞) + Bπ$ (∞)ϕzx ]σxt et+1 + Bgs (∞)σgw wg,t+1 + Bxs (∞)σxw wx,t+1 $′ b $′ Σ b .5 bt+1 , β̃ exp −B∞ (I − Γ̃)X̃t + B ∞ t ε Γ̃ ρ 0 = 0 αx 0 νg 0 0 0 0 νx 0 0 0 0 απ To derive the martingale component of the SDF, let us go back to the SDF itself. Let S̃ ≡ [sx , sgs , sxs , −1]′ . Then the nominal SDF is: M Nt+1 M Nt = = exp µs − µπ + S̃ ′ X̃t − (λη + ϕπg ) σgt ηt+1 − (λe + ϕπx ) σxt et+1 − λgw σgw wg,t+1 − λxw σxw wx,t+1 − σπ ξt+1 ) b $′ Σ.5 exp µs − µπ + S̃ ′ X̃t − Λ ε b t+1 t As a result, the martingale component of the SDF is: P M Nt+1 M NtP = = M Nt+1 M Nt T M Nt+1 M NtT −1 h i $′ β̃ −1 exp µs − µπ + S̃ ′ + B∞ I − Γ̃ X̃t − [λη + ϕπg + Bπ$ (∞)ϕzg ]σgt ηt+1 −[λe + ϕπx + Bx$ (∞) + Bπ$ (∞)ϕzx ]σxt et+1 = $ $ −[λgw + Bgs (∞)]σgw wg,t+1 − [λxw + Bxs (∞)]σxw wx,t+1 − [σπ + Bπ$ (∞)σz ]ξt+1 h i $′ b$ + B b $ )′ Σ b .5 εbt+1 . β̃ −1 exp µs − µπ + S̃ ′ + B∞ I − Γ̃ X̃t − (Λ ∞ t P We need to verify that the martingale component is a martingale, i.e that Et [Mt+1 /MtP ] = 14 THE AMERICAN ECONOMIC REVIEW MAY 2010 1. To do so, recall that the bond parameters evolve as: Bx$ (n) = $ Bgs (n) = $ Bxs (n) = Bπ$ (n) = ρBx$ (n − 1) + αx Bπ$ (n − 1) − sx i2 1h $ νg Bgs (n − 1) − sgs − λη + ϕπg + ϕzg Bπ$ (n − 1) 2 i2 1h $ λe + ϕπx + Bx$ (n − 1) + ϕzx Bπ$ (n − 1) νx Bxs (n − 1) − sxs − 2 απ Bπ$ (n − 1) + 1. Taking limits as n → ∞ leads to: i2 i2 ′ 1h 1h B(∞)$′ (I−Γ̃)+S̃ ′ = 0, − λη + ϕπg + ϕzg Bπ$ (∞) , − λe + ϕπx + Bx$ (∞) + ϕzx Bπ$ (∞) , 0 . 2 2 To check the martingale condition, we plug in the definition of β̃ in the expression for the martingale component of the nominal SDF, and use the above equation for B(∞)$′ (I− Γ̃) + S̃ ′ . After some algebra, we indeed find that Et P M Nt+1 M NtP = 1. We now turn to the conditional variances of the log SDF and its dominant pricing and $,T $,P $ martingale components, Vart [sdft+1 ], Vart [sdft+1 ] and Vart [sdft+1 ]. $ Vart [sdft+1 ] = = $,T Vart [sdft+1 ] = 2 2 2 2 2 2 + λ2gw σgw + λ2xw σxw + σπ2 (λη + ϕπg ) σgt + (λe + ϕπx ) σxt b $′ b b$ Λ ∞ Σt Λ ∞ 2 2 Bπ$ (∞)2 ϕ2zg σgt + [Bx$ (∞) + Bπ$ (∞)ϕzg ]2 σxt $ 2 $ 2 + Bxs (∞)2 σxw + Bπ$ (∞)2 σz2 +Bgs (∞)2 σgw = $,P Vart [sdft+1 ] = $′ b b $ b∞ B Σt B∞ 2 2 + [λe + ϕπx + Bx$ (∞) + Bπ$ (∞)ϕzx ]2 σxt [λη + ϕπg + Bπ$ (∞)ϕzg ]2 σgt $ 2 $ 2 +[λgw + Bgs (∞)]2 σgw + [λxw + Bxs (∞)]2 σxw + [σπ + Bπ$ (∞)σz ]2 = $ ′ b b$ $ b$ + B b∞ b∞ (Λ ) Σt (Λ + B ) P The conditional variance ratio Vart [sdft+1 ]/Vt [sdft+1 ] equals $,P Vt [sdft+1 ] $ Vt [sdft+1 ] =1− b $′ Σ b b $ 1 b $′ b b $ −B ∞ t Λ − 2 B∞ Σt B∞ 1 b $′ b b $ Λ Σt Λ 2 ∞ ∞ The first term in the numerator corresponds to the nominal bond risk premium of an infinite horizon bond, which includes a Jensen term. The second term in the numerator is that Jensen term. As a result, the numerator corresponds to the nominal bond risk premium without the Jensen term. The denominator corresponds to the maximum nominal risk premium, also without the Jensen term. VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO VII. 15 Calibration Table 1 reports the model parameter values we use; they are the ones proposed in Bansal and Shaliastovich (2007). Table 2 reports the model loadings on state variables. The model is simulated for 60,000 months and aggregated up to quarterly frequency 2 for comparison with our quarterly data. In the simulation, negative values for σg,t+1 and 2 σx,t+1 are replaced by very small positive values in simulation. Table 4 reports the mean, standard deviation and autocorrelation of the stochastic discount factor (SDF ), its martingale (SDF P ) and dominant pricing (SDF T ) components, the conditional variance ratio ω, the maximum risk premium without Jensen adjustment (M ax RP ) and the risk premium of an infinite maturity bond without Jensen adjustment (BRP (∞)). Table 3 reports the mean and standard deviations of the real and nominal yields and bond risk premia in the model and compare them to the same moments in the actual nominal data. Table 5 reports moments of quarterly inflation in the model and in the data. Quarterly inflation is obtained as the sum of three consecutive monthly inflation rates. The Bansal and Shaliastovich (2007) calibration generates an annual consumption growth rate of 2.12 percent with a standard deviation of 3.52 percent. It generates an annual inflation rate of 3.52 percent with a standard deviation of 2.49 percent. VIII. Robustness Checks As robustness checks, we considered both changes on the real and on the nominal side of the economy. On the real side, we conduct two experiments. First, we find that a slight decrease in the persistence of the long-run component in consumption growth ρx could decrease the long-horizon consumption variance ratios and the real variance ratio significantly, and increase the long term real yield from negative to positive values. As a result, the model would need to rely less on a large inflation risk premium in order to match the nominal yield curve, thus lowering the variation of MtT in the nominal pricing kernel. However, if all the other parameters are maintained at their previous values, the model would then imply too much volatility of the wealth-consumption ratio and an equity risk premium that is much too low. Second, we shut down the heteroscedasticity in consumption growth by calibrating σxw and σgw to very low values. We keep all the other parameters at their previous values. In this case, the real and nominal conditional variance ratios are respectively 1.20 and 0.63 (see Table 6). They are closer to 1, but equity and bond risk premia are constant. On the nominal side, we first check the robustness of our results to a slightly different calibration of the inflation dynamics. First, we vary each inflation parameter independently in either direction. We report in Table 7 the mean maximum risk premium (M RP ), the mean bond risk premium BRPJ (including the Jensen term) and the mean variance ratio ω for different values of the inflation parameters. We simulate the model for a low and a high value of each parameter (25 percent above and below the benchmark value reported in Table 1). The only exception is the parameter απ , which we cannot increase by 25 percent without running into stationarity issues. The high value is a 10 percent increase for that parameter. We find that ωt only changes noticeably with αx and απ . To further investigate the sensitivity to these two parameters, Figure 1 in the appendix plots ωt (left axis) and the five-year nominal bond risk premium (right axis) against αx (horizontal axis). As we vary αx away from its benchmark value of -0.35, we simultaneously vary απ to match the observed persistence of quarterly inflation. We also choose µπ and σπ to keep the mean and volatility of inflation at their benchmark values. The 16 THE AMERICAN ECONOMIC REVIEW MAY 2010 figure shows that ωt is essentially unchanged over a wide range of values for αx and never comes close to the desired value of one. Next, we consider a calibration that matches the observed mean, variance, and persistence of inflation, the 5-1-year yield spread, and the persistence of the 5-year nominal bond risk premium. This calibration delivers a nominal variance ratio ωt that is much too high. Finally, we ask whether we can find inflation parameters that deliver a nominal variance ratio of 1. We find that we can, while matching the mean inflation, the slope of the nominal term structure, and the persistence of the nominal BRP, but inflation ends up being 2.5 times too volatile and not persistent enough. 5 ω BRP ω 4.5 0.8 4 0.7 3.5 0.6 3 0.5 2.5 0.4 2 0.3 1.5 0.2 1 0.1 0.5 0 −0.9 −0.8 −0.7 −0.6 −0.5 α −0.4 −0.3 −0.2 5Yr Nominal Bond Risk Premium 1 0.9 0 −0.1 x Figure 1. Variance Ratio and Nominal Bond Risk Premium: Sensitivity Analysis The figure plots the conditional variance ratio ωt (against the left axis) and the five-year nominal bond risk premium (against the right axis) for different values of the parameter αx (on the horizontal axis). As we vary αx away from its benchmark value of -0.35, we simultaneously vary απ to match the observed persistence of quarterly inflation. We also choose µπ and σπ to keep the mean and volatility of inflation at their benchmark values. IX. Empirical Variance Ratios Alvarez and Jermann (2005) show that – assuming that the process Xt satisfies the same regularity conditions as above and that Xt+1 /Xt is strictly stationary and limk→∞ k1 Var(Et+k [Xt ]) = 0 – then P Xt+1 1 Xt+k Var = lim Var , k→∞ k Xt XtP Note that the entropy measure used by Alvarez and Jermann (2005) collapses to the halfvariance since all variables are conditionally normal. This result implies that long-horizon variance ratios are informative about the variance of the martingale component. We now turn to the empirical variance ratios of the two components of the SDF, e.g consumption growth and the wealth consumption ratio. If changes in log consumption or changes in the log wealth-consumption ratio are i.i.d, then the variance of long-horizon changes in each variable should grow with the horizon. Ph We compute variance ratios at horizon h as V R(h) = Var[ j=0 ∆xt+j ]/[hVar(∆xt )], for x = c and x = wc. We simulate the model at monthly frequency. Table 1 in the appendix reports the model parameters. We start from the parameter values in Bansal and Shaliastovich (2007). VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO 17 Figure 2 reports these variance ratios for consumption growth, the change in the wealthconsumption ratio, and inflation. The left panel corresponds to actual data; the right panel uses simulated series. Let us first focus on actual data. The variance ratio of the wealth-consumption ratio clearly decreases with the horizon. It is below 0.6 within five years. Consumption growth exhibits a very different pattern: its variance ratio first increases for horizons up to 5 years; it then decreases, but even after 15 years, the variance ratio is still above one. As a result, there is strong evidence of persistence and mean-reversion in the wealth-consumption ratio, but not in consumption growth. Let us now turn to simulated data. The variance ratios of the wealth-consumption ratio are in line with the data. They decrease linearly with the horizon, from 1 to approximately 0.5 at the 30-year horizon. In the data, the variance ratio decreases from 1 to 0.6. Consumption growth, however, exhibits a very different pattern. At long horizons, it displays more persistence in the model than in the data. The bottom panel shows that the inflation persistence is similar in model and data, with a slight divergence maybe at longer horizons. Model:Consumption Growth 20 15 15 VR(h) VR(h) Data: Consumption Growth 20 10 5 0 5 0 20 40 0 60 1 0.5 0 20 40 0 60 0.5 0 60 0 20 40 60 Model: Inflation 30 VR(h) 30 VR(h) 40 1 Data: Inflation 20 10 0 20 Model: Change in Log Wealth−Consumption Ratio 1.5 VR(h) VR(h) Data: Change in Log Wealth−Consumption Ratio 1.5 0 10 0 20 40 Horizon (h) in quarters 60 20 10 0 0 20 40 60 Horizon (h) in quarters Figure 2. Variance Ratios for Consumption Growth, the Change in the Log Wealth Consumption Ratio and Inflation in the Data and in the Model. P The variance ratio of ∆xt is equal to V R(h) = V ar[ h j=0 ∆xt+j ]/[hV ar(∆xt )]. The left panel corresponds to actual data. The right panel corresponds to simulated data. Data are quarterly. Actual data come from Lustig et al. (2009). The sample is 1952:II-2008:IV. 18 THE AMERICAN ECONOMIC REVIEW MAY 2010 REFERENCES Alvarez, Fernando and Urban Jermann, “Using Asset Prices to Measure the Measure the Persistence of the Marginal Utility of Wealth.,” Econometrica, 2005, (4), 1977–2016. Bansal, Ravi and Ivan Shaliastovich, “Risk and Return in Bond, Currency, and Equity Markets,” June 2007. Working Paper Duke University. Campbell, John Y., “A Variance Decomposition for Stock Returns,” Economic Journal, 1991, 101, 157–179. Epstein, Larry and Stan Zin, “Substitution Risk Aversion and the Temporal Behavior of Consumption and Asset Returns: A Theoretical Framework,” Econometrica, 1989, 57, 937–968. Lustig, Hanno, Stijn Van Nieuwerburgh, and Adrien Verdelhan, “The Wealth-Consumption Ratio,” August 2009. Working Paper. VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO 19 Table 1—Model Parameter Values Parameter Preference Parameters: Subjective discount factor Intertemporal elasticity of substitution Risk aversion coefficient BS(2007) δ ψ γ 0.9987 1.5 8 Consumption Growth Parameters: Mean of consumption growth Long-run risk persistence News volatility level News volatility persistence News volatility of volatility Long run-risk volatility level Long run-risk volatility persistence Long run-risk volatility of volatility µg ρ σg νg σgw σx νx σxw 0.0016 0.991 0.004 0.85 1.15e − 6 0.004σg 0.996 0.062 σgw Dividend Growth Parameters: Mean of dividend growth Dividend leverage Dividend loading on news volatility Dividend loading on long-run risk volatility Volatility loading of dividend growth Correlation of consumption and dividend news µd φx φgs φxs ϕd τgd 0.0015 1.5 0 0 6.0 0.1 Inflation Parameters: Mean of inflation rate Inflation leverage on news Inflation leverage on long-run news Inflation shock volatility Expected inflation AR coefficient Expected inflation loading on long-run risk Expected inflation leverage on news Expected inflation leverage on long-run news Expected inflation shock volatility µπ ϕπg ϕπx σπ απ αx ϕzg ϕzx σz 0.0032 0 −2.0 0.0035 0.83 −0.35 0 −1.0 4.0e − 6 This table reports the calibrated parameters values for our simulation. We take them from Table IV and Table C.I in Bansal and Shaliastovich (2007). MAY 2010 Table 2—Model Loadings on State Variables constant wc µwc 6.4 pd µpd 2 σgt − σg2 x 1 1− ψ Wx = κc 1 −ρ Wgs = 31 Dx = 1 φx − ψ κ1 −ρ Dgs = THE AMERICAN ECONOMIC REVIEW 1 ERP BRP (Real) BRP (Nominal) 66 2 (1 − θ) Wgs Dgs σgw 2 + (1 − θ) Wxs Dxs σxw 2 +ϕd τgd γσg +Dx (θ − 1) Wx σx2 1 −1 2 θ ψ 2(κc 1 −νg ) Wxs = 2 1 γ 2 −2γϕ τ d dg +ϕd 2 κ1 −νg i 1 (1−γ)+φ γ− ψ gs [ h κ1 −νg θ 2(νx −κc 1) 1 −1 ψ κc 1 −ρ 2 −1.8 × 106 −7.7 +2 5.6 2 σxt − σx2 ] Dxs = " γ− 1 ψ 1 2 1 −φ x +ψ ρ−κ1 ρ−κc 1 #2 + ( (1−γ) γ− 1 ψ 2 ρ−κc 1 ( ) κ1 −νx xs + κ1φ−ν x 1.3 × 102 −4.3 × 106 Ggs = γϕd τgd Gxs = (1 − θ) Wx Dx 0.003 0 4.8 4.6 × 104 2 (θ − 1) Wgs Bgs (n − 1)σgw 2 + (θ − 1) Wxs Bxs (n − 1)σxw + (θ − 1) Wx Bx (n − 1)σx2 Fx (n) = 0 Fgs (n) = 0 Fxs (n) = (θ − 1) Wx Bx (n − 1) −0.0014 0 0 −2.1 × 104 $ 2 (θ − 1) Wgs Bgs (n − 1)σgw $ 2 + (θ − 1) Wxs Bxs (n − 1)σxw Fx$ (n) = 0 $ Fgs (n) = − (γ + ϕπg ) ×ϕzg Bπ$ (n − 1) $ Fxs (n) = [(θ − 1) Wx − ϕπx ] × Bx$ (n − 1) + Bπ$ (n − 1)ϕzx 0 −0 +σπ σz Bπ$ (n − 1) $ 2 − (γ + ϕπg ) ϕzg Bπ (n − 1)σg + ((θ − 1) Wx − ϕπx ) Bx$ (n − 1) + Bπ$ (n − 1)ϕzx σx2 4.3 × 104 20 0.0015 ) This table reports the model loadings on a constant and the state variables. We consider the log wealth-consumption ratio (wc), the log price-dividend ratio (pd), the equity risk premium (ERP ), the real and nominal bond risk premia (BRP ) at the n-year horizon. VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO 21 Table 3—Real and Nominal Yield Curves 1 2 3 M ean Y ields 5.33 5.52 5.69 5.80 5.89 Std 2.81 2.77 2.70 2.69 2.65 M aturity 4 5 30 200 Nominal Bonds - Data Nominal Bonds - Model M ean Y ields 5.19 5.46 5.75 6.06 6.38 12.82 20.02 Std 2.92 2.79 2.65 2.53 2.43 1.60 0.36 M ean BRP 0.33 0.93 1.59 2.27 2.97 16.81 24.43 Std 0.07 0.18 0.28 0.38 0.46 1.13 1.18 Real Bonds - Model M ean Y ields 1.26 1.05 0.83 0.61 0.39 −4.71 −13.63 Std 1.39 1.35 1.32 1.30 1.29 1.10 0.25 −0.39 −0.83 −1.28 −1.73 −2.19 −11.14 −16.21 0.05 0.10 0.15 0.19 0.23 0.52 0.55 M ean BRP Std The top panel reports the mean and standard deviation of nominal bond yields in the Fama-Bliss data. The data are for 1952 until 2008, and only bond yields of maturities one through five years are available. The maturity is in years. The yields and returns are annualized and reported in percentage points. The middle panel does the same for nominal bond yields for a 60,000 month simulation of the LRR model. It also reports the mean and standard deviation of the nominal bond risk premia. The bottom panel reports the same model-implied moments for real bonds. Table 4—Conditional Variance Ratio M ean Std AR(1) Nominal SDF SDF $ SDF $,P SDF $,T ωt$ M ax RP BRP (∞) 0.99 1.00 0.98 0.37 30.62 18.72 SDF SDF P SDF T ωt M ax RP BRP (∞) 1.00 1.00 1.02 1.65 30.69 −19.05 0.23 0.14 0.10 0.06 2.52 1.04 −0.01 −0.01 −0.01 0.98 0.99 0.99 Real SDF 0.23 0.30 0.07 0.11 2.54 0.58 −0.01 −0.01 −0.01 0.98 0.99 0.99 This table reports the mean, standard deviation and autocorrelation of the stochastic discount factor (SDF ), its martingale (SDF P ) and dominant pricing (SDF T ) components, the conditional variance ratio ω, the maximum risk premium without Jensen adjustment (M ax RP ) and the risk premium of an infinite maturity bond without Jensen adjustment (BRP (∞)). The table reports the autocorrelation of each monthly variable in logs. The top (bottom) panel focuses on the nominal (real) stochastic discount factor. The numbers are computed from a 60,000 month simulation. 22 THE AMERICAN ECONOMIC REVIEW MAY 2010 Table 5—Inflation: Model vs Data Data πt Model M ean Std AR(1) M ean Std AR(1) 0.85 0.62 0.86 0.88 1.25 0.76 This table reports the mean, standard deviation and autocorrelation of the quarterly inflation rate. The left panel corresponds to actual data, from Lustig, Van Nieuwerburgh and Verdelhan (2009). The right panel corresponds to simulated data, from the model. The mean and standard deviation are in percentage. Table 6—Conditional Variance Ratio: No Heteroscedasticity M ean Std AR(1) Nominal SDF SDF $ SDF $,P SDF $,T ωt$ M ax RP BRP (∞) SDF SDF P SDF T ωt M ax RP BRP (∞) 1.00 1.00 1.00 1.20 8.74 −1.74 0.99 1.00 0.99 0.63 8.70 3.18 0.12 0.13 0.01 0.00 0.00 0.00 −0.01 −0.01 −0.01 1.00 1.00 1.00 Real SDF 0.12 −0.01 0.10 −0.01 0.03 −0.01 0.00 1.00 0.00 1.00 0.00 1.00 This table reports the mean, standard deviation and autocorrelation of the stochastic discount factor (SDF ), its martingale (SDF P ) and dominant pricing (SDF T ) components, the conditional variance ratio ω, the maximum risk premium without Jensen adjustment (M ax RP ) and the risk premium of an infinite maturity bond without Jensen adjustment (BRP (∞)). The table reports the autocorrelation of each monthly variable in logs. The top (bottom) panel focuses on the nominal (real) stochastic discount factor. The numbers are computed from a 60,000 month simulation. VOL. 100 NO. 2 THE WEALTH-CONSUMPTION RATIO 23 Table 7—Sensitivity to Inflation Specification M ax RP BRP (∞) ω Low High Low High Low High µp 30.62 30.62 18.72 18.72 0.37 0.37 ϕπg 30.62 30.62 18.72 18.72 0.37 0.37 ϕπx 30.64 30.60 18.70 18.74 0.37 0.37 σπ 30.62 30.62 18.72 18.72 0.37 0.37 απ 30.62 30.62 5.61 26.42 0.81 0.10 αx 30.62 30.62 14.54 21.84 0.51 0.27 ϕzg 30.62 30.62 18.72 18.72 0.37 0.37 ϕzx 30.62 30.62 18.63 18.81 0.38 0.37 σz 30.62 30.62 18.72 18.72 0.37 0.37 This table reports the mean maximum risk premium (M ax RP ) , the mean bond risk premium BRP (∞) (including the Jensen term) and the mean variance ratio ω. We vary one parameter at a time, and simulate the model for a low and a high value of each parameter (25 percent above and below the benchmark value reported in the first column of Table 1). The only exception is the parameter απ , which we cannot increase by 25 percent without running into stationarity issues. The high value is a 10 percent increase for that parameter.
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