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Modeling Bond Return Predictability
Antonio Gargano1 Davide Pettenuzzo2 Allan Timmermann3
1University of Melbourne 2Brandeis University
3UC San Diego
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 1/55
Predictability of bond returns
Literature on predictability of bond excess returns
Fama and Bliss (1987, AER): Forward spreadCampbell and Shiller (1991, JF): Treasury yield spreadsCochrane and Piazzesi (2005, AER): Linear combination of five forwardspreadsLudvigson and Ng (2008, RFS): Macro factors
Literature uses simple linear regression methods
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 2/55
Predictability of bond returns: Existing research
Literature reports large and highly significant R2-values usingoverlapping one-year returns
18% (Fama and Bliss)30-35% (Cochrane-Piazzesi)Wei and Wright (JAE, 2011): finite sample issues with highlypersistent, lagged endogenous regressors—reverse regressions
In-sample versus out-of-sample (OoS) results
Ludvigsson and Ng (RFS, 2008): some OoS predictability
Economic versus statistical measures of forecast performance
Thornton and Valente (2012), Sarno et al. (2014): OoS predictabilitycannot be exploited for economic gains
Macro-finance approaches
Dewachter, Iania, Lyrio (2014): weak OoS predictability
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 3/55
Modeling approach in this paper
Develop Bayesian modeling approach
Generate density forecasts—important for utility and log-score evaluation
Account for parameter estimation error
Thornton and Valente (RFS, 2012) use shrinkage for mean parameters
Incorporate stochastic volatility and time-varying parameters
Thornton and Valente (2012) use rolling-window estimate of volatility
Account for model uncertainty
Geweke-Amisano (JoE 2011) optimal pool (log-score criterion)
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 4/55
Empirical contributions
Most studies use a one-year return horizon, overlapping data
Here: new data with non-overlapping monthly excess bond returns
Time-varying parameters and stochastic volatility—e.g., 1979-1982
Term structure of return predictability: Study bond returnpredictability at monthly, quarterly, annual horizons
Reconcile evidence on statistical and economic measures of returnpredictability
Our empirical findings uncover both economic and statistical gains
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 5/55
1 Introduction
2 Data construction
3 Regression Models
4 Estimation MethodsLinear modelStochastic Volatility modelTime-varying Parameter ModelTime-varying Parameter, Stochastic Volatility Model
5 Empirical Results
6 Forecast Combinations
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 6/55
Data construction
Gurkaynak et al. (2007) reconstruct the entire yield curve for n-periodbonds using Nelson-Siegel smoothing methods:
y (n)t = β0 + β1
1− exp(− n
τ1
)nτ1
+ β2
1− exp(− n
τ1
)nτ1
− exp(− n
τ1
)+β3
1− exp(− n
τ2
)nτ2
− exp(− n
τ2
)Gurkaynak et al. estimate the parameters (β0, β1, β2, β3, τ1, τ2) ondaily cross-sections
We use log yields ranging from 12 months to 60 months and focus onthe last day of each month’s estimated log yields
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 7/55
Constructing excess returns and forward rates
h : frequency at which returns are computed: h = 1, 3, 12 formonthly, quarterly and annual data
n : maturity (in years) of bonds
For any n and h returns and forward rates are computed as follows:
1 Returns and excess returns (for n > h/12):
r (n)t+h/12 =p(n−h/12)t+h/12 − p
(n)t = ny (n)t − (n− h/12)y (n−h/12)
t+h/12
rx (n)t+h/12 =r(n)t+h/12 − y
h/12t (h/12)
2 Forward rates:
f (n−h/12,n)t = p(n−h/12)
t − p(n)t = ny (n)t − (n− h/12)y (n−h/12)t
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 8/55
In-sample regressions
Regressions use non-overlapping bond returns on data from 1962:01to 2011:12
We consider all possible model combinations obtained from threecommon predictors from the literature
Forward spreads (Fama-Bliss)Linear combination of forward rates (Cochrane-Piazzesi)Linear combination of macro factors (Ludvigson-Ng)
Forward spreads (Fama-Bliss)
fs(n,h)t = f (n−h/12,n)t − y (h/12)
t (h/12)
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 9/55
Cochrane-Piazzesi (2005) factor
m : set containing the predicted maturities. The Cochrane-Piazzesifactor is
f(n−h/12,n|m)t = γ′CP f
(n−h/12,n)t
for n = [1, 2, 3, 4, 5] and m = [2, 3, 4, 5], γCP is obtained from
1dim(m) ∑
mrx (m)t+h/12 =γ0 + γ′CP f
(n−h/12,n)t + εt+h/12
=γ0 + γ1f(n1−h/12,n1)t + γ2f
(n2−h/12,n2)t
+ ...+ γk f(nk−h/12,nk )t + εt+h/12
f(n−h/12,n)t =
[f (n1−h/12,n1)t , f (n2−h/12,n2)
t , ..., f (nk−h/12,nk )t
]Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 10/55
Ludvigson-Ng Macro factor
T ×M panel of macroeconomic data xi ,t with factor structure
xi ,t = λi ,tgt + εi ,t
gt : estimate of r × 1 vector gt obtained through PC analysisFollowing Ludvigson & Ng, we use G5t = [g1,t , g31,t , g3,t , g4,t , g8,t ] tobuild a single linear combination of these factors:
G5(m)t = γ′LNG5t ,
γ is obtained from a regression
1dim(m) ∑
mrx (m)t+N/12 =γ0 + γ′LNG5t + ut+1
=γ0 + γ1g1,t + γ2g31,t + γ3g3,t
+ γ4g4,t + γ5g8,t + ut+1
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 11/55
Monthly Regression Models
Time and increments of time are measured in months
Sample period: 1962:1 to 2012:12
We predict one month ahead each month
Expectation Hypothesis (no predictability) benchmark
rx (n)t+1 = β0 + εt+1
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 12/55
Univariate prediction models
Fama-Bliss regression (FB)
rx (n)t+1 = β0 + β1(f(n−1/12,n)t − y1/12
t ) + εt+1
Cochrane-Piazzesi (CP)
rx (n)t+1 = β0 + β1
(γ′CP f
(n−1/12,n)t
)+ εt+1
Ludvigson-Ng (LN)
rx (n)t+1 = β0 + β1
(γ′LNG5t
)+ εt+1
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 13/55
Bi- and trivariate prediction models
Fama-Bliss, Cochrane Piazzesi (FB-CP)
rx (n)t+1 = β0 + β1(f(n−1/12,n)t − y1/12
t ) + β2γ′CP f
(n−1/12,n)t + εt+1
Fama-Bliss, Ludvigson-Ng (FB-LN)
rx (n)t+1 = β0 + β1(f(n−1/12,n)t − y1/12
t ) + β2γ′LNG5t + εt+1
Cochrane-Piazzesi, Ludvigson-Ng (CP-LN)
rx (n)t+1 = β0 + β1γ′CP f
(n−1/12,n)t + β2γ
′LNG5t + εt+1
Fama-Bliss, Cochrane-Piazzesi, Ludvigson-Ng (FB-CP-LN)
rx (n)t+1 = β0 + β1(f(n−1/12,n)t − y1/12
t ) + β2γ′CP f
(n−1/12,n)t
+β3γ′LNG5t + εt+1
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 14/55
Linear regression model
Model bond excess returns rx (n)τ+1 as a linear function of lagged
predictor variables, x(n)τ
rx (n)τ+1 = µ+ β′x(n)τ + ετ+1, τ = 1, ..., t − 1,ετ+1 ∼ N(0, σ2ε )
Priors for µ and β are assumed to be normal and independent of σ2ε[µβ
]∼ N (b,V )
We use a "no-predictability" prior
b =
[rx (n)t0
], V = ψ2
[s2rx ,t
t−1∑τ=1
x(n)τ x(n)′τ
].
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 15/55
Priors (linear model)
Data-based moments
rx (n)t =1
t − 1t−1∑τ=1
rx (n)τ+1,
s2rx ,t =1
t − 2t−1∑τ=1
(rx (n)τ+1 − rx
(n)t
)2ψ = n/2 : controls the tightness of the prior: ψ→ ∞ yields diffusepriors on µ and β
Gamma prior for the error precision of the return innovation, σ−2ε :
σ−2ε ∼ G(s−2rx ,t , v0 (t − 1)
)v0 = 2/n : prior hyperparameter that controls the informativeness.v0 → 0 yields a diffuse prior on σ−2ε
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 16/55
Draws from linear Model
Draws from the joint posterior distribution p(
µ, β, σ−2ε
∣∣Dt) combinepriors with the likelihood function to get posteriors:[
µβ
]∣∣∣∣ σ−2ε ,Dt ∼ N(b,V
),
σ−2ε
∣∣ µ, β,Dt ∼ G(s−2, v
)Gibbs sampler can be used to iterate back and forth between blocksof parameters
(µ, β, σ−2ε
)Draws from the predictive density p
(rx (n)t+1
∣∣∣Dt) are obtained fromp(rx (n)t+1
∣∣∣Dt) =∫
µ,β,σ−2ε
p(rx (n)t+1
∣∣∣ µ, β, σ−2ε ,Dt)p(
µ, β, σ−2ε
∣∣Dt)×dµdβdσ−2ε
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 17/55
Stochastic Volatility (SV) model
SV model:
rx (n)τ+1 = µ+ β′x(n)τ + exp (hτ+1) uτ+1, uτ+1 ∼ N (0, 1)
hτ+1 : (log of) bond return volatility at time τ + 1
log-volatility is assumed to evolve as a driftless random walk
hτ+1 = hτ + ξτ+1, ξτ+1 ∼ N(0, σ2ξ
)
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 18/55
Priors for SV Model
Writing p(ht , σ−2ξ
)= p
(ht | σ−2ξ
)p(
σ−2ξ
), we have
p(ht∣∣ σ−2ξ
)=
t−1∏τ=1
p(hτ+1| hτ, σ
−2ξ
)p (h1)
hτ+1| hτ, σ−2ξ ∼ N
(hτ, σ
2ξ
)To complete the prior elicitation for p
(ht , σ−2ξ
)we only need to
specify priors for h1, the initial log volatility, and σ−2ξ :
h1 ∼ N (ln (srx ,t ) , kh)
σ−2ξ ∼ G(1/kξ , 1
)Choose hyperparameters to imply uninformative priors, allowing thedata to determine the degree of time variation in return volatility
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 19/55
Draws from Stochastic Volatility Model
To obtain draws from the joint posterior distributionp(
µ, β, ht , σ−2ξ
∣∣∣Dt) under the SV model, we use the Gibbs samplerto draw recursively from the following three conditional distributions:
1 p(ht | µ, β, σ−2ξ ,Dt
).
2 p(
µ, β| ht , σ−2ξ ,Dt).
3 p(
σ−2ξ
∣∣∣ µ, β, ht ,Dt).
We employ the algorithm of Kim et al. (1998) to simulate from theseblocks
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 20/55
Draws from SV model (cont.)
Draws from the predictive density p(rx (n)t+1
∣∣∣Dt) :
p(rx (n)τ+1
∣∣∣Dt) =∫
µ,β,ht+1,σ−2ξ
p(rx (n)τ+1
∣∣∣ ht+1, µ, β, ht , σ−2ξ ,Dt)
×p(ht+1| µ, β, ht , σ−2ξ ,Dt
)×p(
µ, β, ht , σ−2ξ
∣∣∣Dt) dµdβdht+1dσ−2ξ .
p(rx (n)t+1
∣∣∣ ht+1, µ, β, ht , σ−2ξ ,Dt): predictive density of excess returns
given the model parameters
p(ht+1| µ, β, ht , σ−2ξ ,Dt
): reflects how period t + 1 volatility may
drift away from ht over time
p(
µ, β, ht , σ−2ξ
∣∣∣Dt) : parameter uncertainty in the sample
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 21/55
Draws from SV model (cont.)
To obtain draws from p(rx (n)t+1
∣∣∣Dt), we proceed in three steps:1 Simulate from p
(µ, β, ht , σ−2ξ
∣∣∣Dt): draws fromp(
µ, β, ht , σ−2ξ
∣∣∣Dt) are obtained from the Gibbs sampling algorithm2 Simulate from p
(ht+1| µ, β, ht , σ−2ξ ,Dt
): For a given ht and σ−2ξ , µ
and β and prior volatilities up to t become redundant, i.e.,
p(ht+1| µ, β, ht , σ−2ξ ,Dt
)= p
(ht+1| ht , σ−2ξ ,Dt
), so
ht+1| ht , σ−2ξ ,Dt ∼ N(ht , σ2ξ
)3 Simulate from p
(rx (n)t+1
∣∣∣ ht+1, µ, β, ht , σ−2ξ ,Dt): For a given ht+1, µ,
and β, use that
rx (n)t+1
∣∣∣ ht+1, µ, β,Dt ∼ N (µ+ β′x(n)τ , exp (ht+1))
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 22/55
Time-varying parameter (TVP) model
rx (n)τ+1 = µτ + β′τx(n)τ + ετ+1, τ = 1, ..., t − 1,
ετ+1 ∼ N(0, σ2ε ).
Assume that θτ =(µτ, β
′τ
)′follows a random walk:
θτ+1 = θτ + ητ+1, ητ+1 ∼ N (0,Q) .
We work with an equivalent version which sets θ1 = 0 and uses
rx (n)τ+1 = (µ+ µτ) + (β+ βτ)′ x(n)τ + ετ+1, τ = 1, ..., t − 1,
ετ+1 ∼ N(0, σ2ε ).
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 23/55
TVP model: Choice of priors
For [µ, β]′ and σ2ε , we follow the same prior choices made under thelinear model section:[
µβ
]∼ N (b,V ) ,
σ−2ε ∼ G(s−2rx ,t , v0 (t − 1)
)
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 24/55
TVP model: Choice of priors (cont.)
TVP model also elicits a joint prior for the sequence θt = {θ2, ..., θt}and the covariance matrix QFor θt and Q, we first write p (θt ,Q) = p
(θt∣∣Q) p (Q), and note
that
p(
θt∣∣Q) = t−1
∏τ=1
p (θτ+1| θτ,Q) , θτ+1| θτ,Q ∼ N (θτ,Q) .
To complete the prior elicitation for p (θt ,Q) , we only need tospecify priors for Q:
Q ∼ IW (Q, t − 2)
Q = kQ (t − 2)
s2rx ,t(t−1∑τ=1
x(n)τ x(n)′τ
)−1 .kQ controls the time-variation in the coeffi cients θτ
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 25/55
Time-varying parameter, SV model
Consider a model with both TVP and SV:
rx (n)τ+1 = µτ + β′τx(n)τ + exp (hτ+1) uτ+1,
θτ+1 = θτ + ητ+1,
hτ+1 = hτ + ξτ+1, ητ+1 ∼ N (0,Q) ,
ξτ+1 ∼ N(0, σ2ξ
)
Once again, we set θ1 = 0 and use
rx (n)τ+1 = (µ+ µt ) + (β+ βτ)′ x(n)τ + exp (hτ+1) uτ+1
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 26/55
TVP-SV model: Priors
Our choice of priors combines those made for the TVP and SVmodels: [
µβ
]∼ N (b,V )
σ−2ε ∼ G(s−2rx ,t , v0 (t − 1)
)along with
h1 ∼ N (ln (srx ,t ) , kh)
σ−2ξ ∼ G(1/kξ , 1
)Q ∼ IW (Q, t − 2)
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 27/55
Empirical Results: 2-5 year bond excess returns
Exc
ess
retu
rns
(%)
n = 2 years
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010−10
−8
−6
−4
−2
0
2
4
6
8
10
Exc
ess
retu
rns
(%)
n = 3 years
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010−10
−8
−6
−4
−2
0
2
4
6
8
10
Exc
ess
retu
rns
(%)
n = 4 years
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010−10
−8
−6
−4
−2
0
2
4
6
8
10
Exc
ess
retu
rns
(%)
n = 5 years
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010−10
−8
−6
−4
−2
0
2
4
6
8
10
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 28/55
Descriptive statistics
Bonds Stocks2 years 3 years 4 years 5 years S&P
Panel A: Monthlymean 1.4147 1.7316 1.9868 2.1941 3.7327st.dev. 2.9711 4.1555 5.2174 6.2252 15.2939skew 0.4995 0.2079 0.0566 0.0149 -0.6314kurt 14.8625 10.6482 7.9003 6.5797 5.3510AC(1) 0.1692 0.1533 0.1384 0.1235 0.0601AC(2) -0.0624 -0.0655 -0.0651 -0.0660 -0.0360AC(3) -0.0437 -0.0383 -0.0282 -0.0197 0.0362Sharpe 0.4761 0.4167 0.3808 0.3525 0.2441
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 29/55
OLS regression estimates
Panel A: Monthly(1) (2) (3) (4) (5) (6) (7)
2 yearsFB 1.1648*** 0.6621** 1.3592*** 1.1221***CP 0.6548*** 0.5123*** 0.4905*** 0.2317LN 0.6712*** 0.7091*** 0.6099*** 0.6736***adjR2 0.0166 0.0246 0.0580 0.0277 0.0812 0.0708 0.0821
3 yearsFB 1.3741*** 0.7858** 1.4989*** 1.2060***CP 0.8784*** 0.6769*** 0.6561*** 0.3299LN 0.9068*** 0.9342*** 0.8248*** 0.8876***adjR2 0.0158 0.0225 0.0540 0.0253 0.0732 0.0655 0.0742
4 yearsFB 1.6661*** 1.0071** 1.6936*** 1.3499***CP 1.1053*** 0.8089*** 0.8329*** 0.4202LN 1.1148*** 1.1218*** 1.0107*** 1.0678***adjR2 0.0183 0.0226 0.0517 0.0266 0.0708 0.0635 0.0718
5 yearsFB 1.9726*** 1.2280** 1.9093*** 1.4876***CP 1.3612*** 0.9640*** 1.0441*** 0.5502*LN 1.3070*** 1.2888*** 1.1765*** 1.2240***adjR2 0.0211 0.0242 0.0499 0.0292 0.0697 0.0630 0.0712
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 30/55
Parameters for FB+CP+LN model
β1
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20100
0.5
1
1.5LinearTVPSVTVP−SV
β2
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20100
0.2
0.4
0.6
0.8
β3
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20100
0.5
1
σ
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20100
2
4
6
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 31/55
Posterior parameter distributions
−0.8 −0.6 −0.4 −0.2 0 0.2 0.4 0.60
1
2
3
4
5
6
7
8
9
β0
LinearTVPSVTVP−SV
−3 −2 −1 0 1 2 3 40
0.2
0.4
0.6
0.8
1
1.2
1.4
β1
−2 −1.5 −1 −0.5 0 0.5 1 1.5 2 2.50
0.5
1
1.5
2
2.5
β2
−0.4 −0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.60
0.5
1
1.5
2
2.5
3
3.5
4
4.5
β3
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 32/55
Out-of-sample analysis
Predict 2, 3, 4, and 5 year bond returns (i.e. n = 2, 3, 4, 5)
Expanding estimation window
CP and LN factors are constructed recursively
Out-of-sample-period: 1990 - 2011
Predictability is studied separately for each maturity
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 33/55
Out-of-sample analysis (cont.)
Following Goyal and Welch (2008) we report recursively computeddifferences in the cumulative sum of squared errors (SSE) between theEH model and the ith model:
∆CumSSE (n)t =t
∑τ=t
(e(n)τ
)2−
t
∑τ=t
(e(n)τ,i
)2.
Similarly, following Campbell and Thompson (2008), we compute theout-of-sample R2 of model i relative to the EH model as
R (n)2OoS ,i = 1−∑t
τ=t e(n)2τ,i
∑tτ=t e
(n)2τ
.
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 34/55
Table 5: Out-of-sample R2 results
Panel A: 2 years Panel B: 3 yearsModel OLS LIN SV TVP TVPSV OLS LIN SV TVP TVPSVFB 0.09%∗ 0.81%∗ -0.65% 0.91%∗ -0.60% 1.82%∗∗ 1.42%∗∗ 0.64%∗ 2.13%∗∗ 0.99%∗∗
CP -1.72% 0.36% -0.01% -0.32% 0.24%∗ -0.40% 0.83%∗ 0.24% 0.70%∗ 0.56%∗
LN -0.40% 4.59%∗∗∗ 5.05%∗∗∗ 3.80%∗∗∗ 4.29%∗∗∗ 2.65%∗∗∗ 4.66%∗∗∗ 3.80%∗∗∗ 4.10%∗∗∗ 3.90%∗∗∗
FB + CP -1.34% 0.86%∗ 0.69%∗ -0.14% 0.45%∗∗ 0.57%∗∗ 1.39%∗∗ 1.39%∗∗ 1.40%∗∗ 1.17%∗∗
FB + LN -1.70% 5.32%∗∗∗ 5.94%∗∗∗ 3.09%∗∗∗ 3.86%∗∗∗ 1.36%∗∗∗ 5.62%∗∗∗ 5.28%∗∗∗ 4.44%∗∗∗ 3.78%∗∗∗
CP + LN -3.49% 3.57%∗∗∗ 4.70%∗∗∗ 2.01%∗∗∗ 2.70%∗∗∗ 0.72%∗∗∗ 4.11%∗∗∗ 4.05%∗∗∗ 3.25%∗∗∗ 2.76%∗∗∗
FB + CP + LN -3.20% 4.40%∗∗∗ 5.71%∗∗∗ 2.05%∗∗∗ 2.87%∗∗∗ 0.47%∗∗∗ 4.95%∗∗∗ 4.94%∗∗∗ 3.45%∗∗∗ 2.54%∗∗∗
Panel C: 4 years Panel D: 5 yearsModel OLS LIN SV TVP TVPSV OLS LIN SV TVP TVPSVFB 2.51%∗∗∗ 1.77%∗∗∗ 1.28%∗∗ 2.54%∗∗∗ 1.83%∗∗ 2.76%∗∗∗ 1.79%∗∗∗ 1.49%∗∗ 2.81%∗∗∗ 1.95%∗∗
CP 0.37% 1.00%∗ 0.32% 1.36%∗ 1.13%∗ 0.89%∗ 0.91%∗ 0.47% 1.69%∗ 1.50%∗
LN 3.89%∗∗∗ 4.15%∗∗∗ 2.95%∗∗ 4.54%∗∗∗ 4.08%∗∗∗ 4.47%∗∗∗ 3.53%∗∗∗ 2.30%∗∗ 4.67%∗∗∗ 4.03%∗∗
FB + CP 1.64%∗∗ 1.79%∗∗ 1.66%∗∗ 2.05%∗∗ 1.74%∗∗ 2.28%∗∗ 1.96%∗∗ 1.85%∗∗ 2.55%∗∗ 2.20%∗∗
FB + LN 2.46%∗∗∗ 5.19%∗∗∗ 4.69%∗∗∗ 4.67%∗∗∗ 4.07%∗∗∗ 2.79%∗∗∗ 4.91%∗∗∗ 4.05%∗∗∗ 5.09%∗∗∗ 4.21%∗∗∗
CP + LN 2.57%∗∗∗ 3.92%∗∗∗ 3.45%∗∗ 4.00%∗∗∗ 3.16%∗∗∗ 3.55%∗∗ 3.61%∗∗ 2.99%∗∗ 4.24%∗∗ 3.73%∗∗
FB + CP + LN 2.01%∗∗∗ 4.92%∗∗∗ 4.57%∗∗∗ 4.18%∗∗∗ 3.21%∗∗∗ 2.66%∗∗∗ 4.55%∗∗∗ 4.05%∗∗∗ 4.60%∗∗∗ 3.71%∗∗∗
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 35/55
CumSum squared plots for six models, n = 5
∆ cu
mul
ativ
e S
SE
FB
1985 1990 1995 2000 2005 2010−10
0
10
20
30
40LinearTVPSVTVP−SV
∆ cu
mul
ativ
e S
SE
CP
1985 1990 1995 2000 2005 2010−10
0
10
20
30
40
∆ cu
mul
ativ
e S
SE
LN
1985 1990 1995 2000 2005 2010−10
0
10
20
30
40
∆ cu
mul
ativ
e S
SE
FB + LN
1985 1990 1995 2000 2005 2010−10
0
10
20
30
40
∆ cu
mul
ativ
e S
SE
CP + LN
1985 1990 1995 2000 2005 2010−10
0
10
20
30
40
∆ cu
mul
ativ
e S
SE
FB + CP + LN
1985 1990 1995 2000 2005 2010−10
0
10
20
30
40
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 36/55
Out-of-sample analysis (cont.)
To evaluate the accuracy of the density forecasts, we use the logpredictive score which is commonly viewed as the broadest measure ofdensity accuracy.Denote by LSt and LSti the log of the predictive densities evaluatedat the observed bond excess return r (n)tUse these as inputs to the period-t difference in the cumulative logscore differentials (LS) between the EH model and the ith model:
∆CumLSt =t
∑τ=t[LSτ.i − LSτ] .
Following Clark and Ravazzolo (JAE, 2014) we compute the averagelog predictive scores differential of model i relative to the EH model as
LS i =1
t − t + 1t
∑τ=t(LSτ.i − LSτ)
a positive LS i indicates that model i beats the EH benchmark.Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 37/55
Statistical evaluation of results
Point forecasts use a DM test with finite-sample correction(Harvey-Leybourne-Newbold)
Log predictive score test uses DM test based on equality of averagelog scores
Clark and Ravazzolo (JAE, 2014)Clark and McCracken (JoE, 2011) show that for nested models the DMtest yield conservative finite-sample inference
t-test uses Andrews-Monahan (EcTa, 1992) pre-whitened quadraticspectral estimator
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 38/55
Table 6: Predictive Bayes factors
Panel A: 2 years Panel B: 3 yearsModel LIN SV TVP TVPSV LIN SV TVP TVPSVFB 0.002 0.248∗∗∗ -0.001 0.220∗∗∗ 0.003 0.121∗∗∗ 0.001 0.097∗∗∗
CP 0.004 0.239∗∗∗ -0.000 0.202∗∗∗ 0.005∗∗ 0.119∗∗∗ 0.002 0.095∗∗
LN 0.009∗ 0.252∗∗∗ 0.005 0.207∗∗∗ 0.012∗∗ 0.130∗∗∗ 0.005 0.087∗∗
FB + CP 0.004 0.243∗∗∗ -0.000 0.194∗∗∗ 0.005∗ 0.120∗∗∗ 0.002 0.083∗∗
FB + LN 0.014∗∗ 0.257∗∗∗ 0.007 0.204∗∗∗ 0.015∗∗ 0.131∗∗∗ 0.009 0.075∗∗
CP + LN 0.010∗ 0.240∗∗∗ 0.004 0.183∗∗∗ 0.012∗∗ 0.126∗∗∗ 0.007 0.073∗
FB + CP + LN 0.011∗∗ 0.250∗∗∗ 0.004 0.176∗∗∗ 0.014∗∗ 0.125∗∗∗ 0.006 0.047
Panel C: 4 years Panel D: 5 yearsModel LIN SV TVP TVPSV LIN SV TVP TVPSVFB 0.006∗∗ 0.067∗∗∗ 0.004 0.045∗ 0.006∗∗ 0.033∗ 0.006 0.016CP 0.006∗∗ 0.066∗∗∗ 0.005 0.046∗ 0.005∗∗ 0.028 0.007 0.015LN 0.013∗∗ 0.076∗∗∗ 0.011 0.041 0.012∗∗ 0.036∗ 0.013 0.013
FB + CP 0.008∗∗ 0.063∗∗ 0.006 0.034 0.008∗∗ 0.033∗ 0.009 0.004FB + LN 0.016∗∗ 0.075∗∗∗ 0.012 0.026 0.016∗∗ 0.040∗ 0.014 -0.002CP + LN 0.013∗∗ 0.072∗∗ 0.012 0.026 0.014∗∗ 0.037∗ 0.014 -0.004
FB + CP + LN 0.016∗∗ 0.072∗∗ 0.012 0.002 0.017∗∗ 0.033 0.014 -0.020
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 39/55
Economic value of return forecasts
Investor puts weight ωt on an n−period risky bond and (1−ωt ) on1-month T-bill that pays the riskfree rate, r ftInvestor has power utility and coeffi cient of relative risk aversion A:
U (ωt , rt+1) =
[(1−ωt ) exp
(r ft)+ωt exp
(r ft + rx
nt+1
)]1−A1− A
A = 10
Using information at time t, Dt , the investor solves the optimal assetallocation problem
ω∗t = argmaxωt
∫U (ωt , rxt+1) p
(rxt+1| Dt
)drxt+1
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 40/55
Economic value of return forecasts
Approximate expected utility integral by generating a large number ofdraws, rx jt+1,i , j = 1, .., J, from the predictive densities:
ωt ,i = maxωt
1J
J
∑j=1
[(1−ωt ) exp
(r ft)+ωt exp
(r ft + rx
jt+1,i
)]1−A1− A
To avoid bankruptcy concerns, we restrict the weights on the riskybonds to the interval [0, 0.99]
Sequence of portfolio weights{
ωEHt
}and {ωt ,i} are used to
compute realized utilities and converted into CER-values
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 41/55
Table 7: Out-of-sample CER values, A = 10
Panel A: 2 years Panel B: 3 yearsModel LIN SV TVP TVPSV LIN SV TVP TVPSVFB -0.23% -0.25% -0.21% -0.25% 0.05% 0.17% 0.18% 0.08%CP -0.19% 0.04% -0.24% 0.06% -0.08% 0.21% -0.16% 0.28%LN 0.11% 0.10% 0.09% 0.09% 0.57% 0.64% 0.66% 0.66%
FB + CP -0.21% -0.13% -0.27% -0.10% 0.01% 0.26% 0.08% 0.16%FB + LN 0.07% 0.12% -0.07% 0.01% 0.53% 0.67% 0.38% 0.42%CP + LN 0.09% 0.19% -0.04% 0.01% 0.49% 0.67% 0.46% 0.48%
FB + CP + LN 0.05% 0.14% -0.09% 0.02% 0.47% 0.62% 0.32% 0.43%
Panel C: 4 years Panel D: 5 yearsModel LIN SV TVP TVPSV LIN SV TVP TVPSVFB 0.46% 0.58% 0.56% 0.63% 0.69% 0.74% 0.84% 0.88%CP 0.12% 0.25% 0.15% 0.28% 0.23% 0.35% 0.31% 0.43%LN 0.90% 0.96% 1.19% 1.22% 0.90% 0.97% 1.37% 1.47%
FB + CP 0.38% 0.61% 0.46% 0.62% 0.62% 0.81% 0.71% 0.79%FB + LN 1.03% 1.17% 0.91% 0.83% 1.25% 1.33% 1.26% 1.19%CP + LN 0.73% 1.01% 0.97% 0.97% 0.79% 1.03% 1.13% 1.28%
FB + CP + LN 0.98% 1.13% 0.84% 0.90% 1.11% 1.21% 1.21% 1.19%
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 42/55
cumCER plot for A = 10, FB+CP+LN, n = 3
Con
tinuo
usly
com
poun
ded
CE
Rs
(%)
n=2 years
1985 1990 1995 2000 2005 2010−5
0
5
10
15
20
25
30
35
40LinearTVPSVTVP−SV
Con
tinuo
usly
com
poun
ded
CE
Rs
(%)
n=3 years
1985 1990 1995 2000 2005 2010−5
0
5
10
15
20
25
30
35
40
Con
tinuo
usly
com
poun
ded
CE
Rs
(%)
n=4 years
1985 1990 1995 2000 2005 2010−5
0
5
10
15
20
25
30
35
40
Con
tinuo
usly
com
poun
ded
CE
Rs
(%)
n=5 years
1985 1990 1995 2000 2005 2010−5
0
5
10
15
20
25
30
35
40
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 43/55
Predictability in expansions and recessions
LIN SV TVP TVPSVModel Exp Rec Exp Rec Exp Rec Exp Rec
Panel A: 2 yearsFB 2.86% 0.48% 3.05% 0.11% 4.53% 1.62% 5.49% -0.47%CP 1.53% 4.08%∗∗ 1.87% 3.24%∗ 3.68% 4.63%∗ 4.02% 3.53%∗
LN 1.23% 12.03%∗∗ 1.95% 7.87%∗∗∗ 2.05% 18.04%∗∗ 3.94% 11.54%∗∗
FB + CP 2.62% 3.72%∗ 3.08% 2.78% 5.94% 5.57%∗ 5.94% 2.39%FB + LN 4.97% 12.83%∗∗∗ 5.57% 8.39%∗∗ 6.40% 19.53%∗∗∗ 7.99% 13.42%∗∗
CP + LN 2.66% 13.47%∗∗ 3.41% 8.81%∗∗∗ 4.63% 19.67%∗∗ 5.68% 13.97%∗∗
FB + CP + LN 4.86% 13.51%∗∗∗ 5.56% 8.63%∗∗ 7.86% 20.82%∗∗∗ 8.35% 14.82%∗∗
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 44/55
Equal-weighted combinations
Equal-weighted pool (EWP), putting 1/N weight on each model Mi :
p(rx (n)t+1
∣∣∣Dt) = 1N
N
∑i=1p(rx (n)t+1
∣∣∣Mi ,Dt)
{p(rx (n)t+1
∣∣∣Mi ,Dt)}N
i=1: predictive densities
N = 21
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 45/55
Predictive pool combinations
Real time optimal predictive pool (RTOP) of Geweke and Amisano(2012):
p(rx (n)t+1
∣∣∣Dt) = N
∑i=1w ∗t ,i × p
(rx (n)t+1
∣∣∣Mi ,Dt)
We determine w∗t = [w ∗1t , ...,w∗Nt ] recursively by solving the following
maximization problem at time t,
w∗t = argmaxwt
t−1∑τ=1
log
[N
∑i=1wit × Sτ+1,i
]
w∗t restricted to the N−dimensional unit simplexSτ+1,i : time-τ + 1 recursively computed log score for model i , i.e.Sτ+1,i = exp (LSτ+1,i )
As t → ∞ these weights minimize the Kullback-Leibler distance
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 46/55
Bayesian Model Averaging
BMA weights:
p(rx (n)t+1
∣∣∣Dt) = N
∑i=1Pr(Mi | Dt
)p(rx (n)t+1
∣∣∣Mi ,Dt)
Pr (Mi | Dt ) : posterior probability of model i at time t:
Pr(Mi | Dt
)=
Pr({rx (n)τ+1}t−1τ=1
∣∣∣Mi
)Pr (Mi )
∑Nj=1 Pr
({rx (n)τ+1}t−1τ=1
∣∣∣Mj
)Pr (Mj )
Pr({rx (n)τ+1}t−1τ=1
∣∣∣Mi
): marginal likelihood for model i
Pr (Mi ) = 1/N : prior probability for model iWe compute the marginal likelihoods by cumulating the predictive logscores of each model over time:
Pr({rx (n)τ+1}t−1τ=1
∣∣∣Mi
)= exp
(t
∑τ=t
LSτ.i
).
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 47/55
Optimal prediction pool weightsO
ptim
al p
redi
ctio
n po
ol w
eigh
ts
n=2 years
1985 1990 1995 2000 2005 20100
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1LINSVTVP
Opt
imal
pre
dict
ion
pool
wei
ghts
n=3 years
1985 1990 1995 2000 2005 20100
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Opt
imal
pre
dict
ion
pool
wei
ghts
n=4 years
1985 1990 1995 2000 2005 20100
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Opt
imal
pre
dict
ion
pool
wei
ghts
n=5 years
1985 1990 1995 2000 2005 20100
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 48/55
Optimal prediction pool weights - by factorO
ptim
al p
redi
ctio
n po
ol w
eigh
ts
n=2 years
1985 1990 1995 2000 2005 20100
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2FBCPLN
Opt
imal
pre
dict
ion
pool
wei
ghts
n=3 years
1985 1990 1995 2000 2005 20100
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Opt
imal
pre
dict
ion
pool
wei
ghts
n=4 years
1985 1990 1995 2000 2005 20100
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Opt
imal
pre
dict
ion
pool
wei
ghts
n=5 years
1985 1990 1995 2000 2005 20100
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 49/55
cumSEE plot for model combinations
∆ cu
mul
ativ
e S
SE
n = 2 years
1985 1990 1995 2000 2005 2010−1
0
1
2
3
4
5
6Equal−weighted combinationOptimal prediction pool
∆ cu
mul
ativ
e S
SE
n = 5 years
1985 1990 1995 2000 2005 2010−5
0
5
10
15
20
25
30
35
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 50/55
cumCER plot for A = 10, model combinations
Con
tinuo
usly
com
poun
ded
CE
Rs
(%)
n=2 years
1985 1990 1995 2000 2005 2010−5
0
5
10
15
20
25
30
35
40Equal−weighted combinationOptimal prediction pool
Con
tinuo
usly
com
poun
ded
CE
Rs
(%)
n=3 years
1985 1990 1995 2000 2005 2010−5
0
5
10
15
20
25
30
35
40
Con
tinuo
usly
com
poun
ded
CE
Rs
(%)
n=4 years
1985 1990 1995 2000 2005 2010−5
0
5
10
15
20
25
30
35
40
Con
tinuo
usly
com
poun
ded
CE
Rs
(%)
n=5 years
1985 1990 1995 2000 2005 2010−5
0
5
10
15
20
25
30
35
40
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 51/55
Forecast Combinations
Method 2 years 3 years 4 years 5 yearsOut-of-sample R2
OW 5.92%∗∗∗ 5.55%∗∗∗ 5.05%∗∗∗ 5.16%∗∗∗
EW 4.99%∗∗∗ 4.39%∗∗∗ 4.16%∗∗∗ 3.85%∗∗∗
BMA 5.42%∗∗∗ 4.36%∗∗∗ 3.43%∗∗∗ 3.17%∗∗∗
Predictive LikelihoodOW 0.25∗∗∗ 0.11∗∗∗ 0.05∗∗∗ 0.03∗∗∗
EW 0.14∗∗∗ 0.08∗∗∗ 0.05∗∗∗ 0.04∗∗∗
BMA 0.25∗∗∗ 0.12∗∗∗ 0.05∗∗ 0.02CER
OW 0.15% 0.49% 0.98% 1.30%EW 0.10% 0.53% 0.96% 1.02%BMA 0.14% 0.63% 0.92% 1.14%
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 52/55
Table 8: Robustness to prior
Prior ψ = 5, ν = 0.2Panel A: 2 years Panel B: 3 years
Model OLS LIN SV OLS LIN SVFB 0.11%∗ 0.25%∗ -1.21% 1.77%∗∗ 1.76%∗∗ 0.90%∗∗
CP -1.69% -1.36% 0.14%∗ -0.45% -0.11% 0.66%∗
LN -0.38% 0.30%∗∗∗ 5.03%∗∗∗ 2.60%∗∗∗ 3.45%∗∗∗ 4.39%∗∗∗
FB + CP -1.31% -1.26% 0.34%∗∗ 0.53%∗∗ 0.86%∗∗ 1.90%∗∗
FB + LN -1.67% -0.91% 5.07%∗∗∗ 1.31%∗∗∗ 2.79%∗∗∗ 5.32%∗∗∗
CP + LN -3.46% -2.70% 4.42%∗∗∗ 0.68%∗∗∗ 1.74%∗∗∗ 4.53%∗∗∗
FB + CP + LN -3.17% -2.45% 4.83%∗∗∗ 0.43%∗∗∗ 1.88%∗∗∗ 5.06%∗∗∗
Panel C: 4 years Panel D: 5 yearsModel OLS LIN SV OLS LIN SVFB 2.39%∗∗ 2.47%∗∗∗ 1.72%∗∗ 2.65%∗∗∗ 2.57%∗∗∗ 2.18%∗∗
CP 0.25% 0.72% 0.92%∗ 0.77% 1.02%∗ 0.94%LN 3.77%∗∗∗ 4.58%∗∗∗ 3.79%∗∗∗ 4.35%∗∗∗ 4.76%∗∗∗ 3.00%∗∗
FB + CP 1.52%∗∗ 1.90%∗∗ 2.55%∗∗ 2.17%∗∗ 2.44%∗∗ 2.78%∗∗
FB + LN 2.34%∗∗∗ 4.60%∗∗∗ 5.27%∗∗∗ 2.67%∗∗∗ 5.41%∗∗∗ 4.96%∗∗∗
CP + LN 2.45%∗∗∗ 3.73%∗∗∗ 4.54%∗∗∗ 3.43%∗∗ 4.57%∗∗ 4.02%∗∗
FB + CP + LN 1.89%∗∗∗ 4.19%∗∗∗ 5.10%∗∗∗ 2.55%∗∗∗ 5.19%∗∗∗ 5.01%∗∗∗
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 53/55
Robustness to priors
Prior ψ = 5, ν = 0.2Panel A: 2 years Panel B: 3 years
Model OLS LIN SV OLS LIN SVFB 0.11%∗ 0.25%∗ -1.21% 1.77%∗∗ 1.76%∗∗ 0.90%∗∗
CP -1.69% -1.36% 0.14%∗ -0.45% -0.11% 0.66%∗
LN -0.38% 0.30%∗∗∗ 5.03%∗∗∗ 2.60%∗∗∗ 3.45%∗∗∗ 4.39%∗∗∗
FB + CP -1.31% -1.26% 0.34%∗∗ 0.53%∗∗ 0.86%∗∗ 1.90%∗∗
FB + LN -1.67% -0.91% 5.07%∗∗∗ 1.31%∗∗∗ 2.79%∗∗∗ 5.32%∗∗∗
CP + LN -3.46% -2.70% 4.42%∗∗∗ 0.68%∗∗∗ 1.74%∗∗∗ 4.53%∗∗∗
FB + CP + LN -3.17% -2.45% 4.83%∗∗∗ 0.43%∗∗∗ 1.88%∗∗∗ 5.06%∗∗∗
Panel C: 4 years Panel D: 5 yearsModel OLS LIN SV OLS LIN SVFB 2.39%∗∗ 2.47%∗∗∗ 1.72%∗∗ 2.65%∗∗∗ 2.57%∗∗∗ 2.18%∗∗
CP 0.25% 0.72% 0.92%∗ 0.77% 1.02%∗ 0.94%LN 3.77%∗∗∗ 4.58%∗∗∗ 3.79%∗∗∗ 4.35%∗∗∗ 4.76%∗∗∗ 3.00%∗∗
FB + CP 1.52%∗∗ 1.90%∗∗ 2.55%∗∗ 2.17%∗∗ 2.44%∗∗ 2.78%∗∗
FB + LN 2.34%∗∗∗ 4.60%∗∗∗ 5.27%∗∗∗ 2.67%∗∗∗ 5.41%∗∗∗ 4.96%∗∗∗
CP + LN 2.45%∗∗∗ 3.73%∗∗∗ 4.54%∗∗∗ 3.43%∗∗ 4.57%∗∗ 4.02%∗∗
FB + CP + LN 1.89%∗∗∗ 4.19%∗∗∗ 5.10%∗∗∗ 2.55%∗∗∗ 5.19%∗∗∗ 5.01%∗∗∗
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 54/55
Conclusion
Strong evidence of out-of-sample bond return predictability for 2-5year maturities
Ludvigson-Ng (2008) macro factor performs particularly well
Statistical return predictability carries over to economic returnpredictability
Accounting for SV improves economic and statistical performance
TVP model works well for the longer bond maturities
Forecast combination methods offer economic and statisticalimprovements
Gargano, Pettenuzzo, Timmermann Bond Return Predictability 03/2014 55/55