SLIDE 1
The conditional CAPM does not explain asset- pricing anomalies Jonathan Lewellen & Stefan Nagel HEC School of Management, March 17, 2005
SLIDE 2 2
Background Size, B/M, and momentum portfolios, 1964 – 2001 Monthly returns (%)
CAPM alphas Portfolio Size B/M R-1,-6 Size B/M R-1,-6 Low 0.71 0.41 0.17 0.07
2 0.74 0.58 0.51 0.16 0.03 0.04 3 0.70 0.66 0.43 0.19 0.17
4 0.69 0.80 0.52 0.21 0.35 0.08 High 0.50 0.88 0.79 0.11 0.39 0.29 Long–short 0.21 0.47 0.61
0.59 0.70 t-stat 0.91 2.98 2.76
4.01 3.14
SLIDE 3
3
Background Explained by the conditional CAPM w/ time-varying betas? Theory Jensen (1968) Dybvig and Ross (1985) Hansen and Richard (1987) Application to size, B/M, and momentum Zhang (2002) Jagannathan and Wang (1996) Lettau and Ludvigson (2001) Petkova and Zhang (2004) Lustig and Van Nieuwerburgh (2004) Santos and Veronesi (2004) Franzoni (2004), Adrian and Franzoni (2004) Wang (2003)
SLIDE 4
4
Rolling betas of value stocks, 1930 – 2000
Franzoni (2004)
SLIDE 5
5
Background Explained by the conditional CAPM w/ time-varying betas? Theory Jensen (1968) Dybvig and Ross (1985) Hansen and Richard (1987) Application to size, B/M, and momentum Zhang (2002) Jagannathan and Wang (1996) Lettau and Ludvigson (2001) Petkova and Zhang (2004) Lustig and Van Nieuwerburgh (2004) Santos and Veronesi (2004) Franzoni (2004), Adrian and Franzoni (2004) Wang (2003)
SLIDE 6
6
Background Conditional CAPM Rit = αt + βt RMt + εt αt = 0 Empirical tests with constant β Rit = α + β RMt + εt α ≠ 0
SLIDE 7
7
Intuition 1 Alternate between efficient portfolios A and B
B A Dynamic strategy .5 A + .5 B
0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0
SLIDE 8 8
Intuition 2 Rt = βt RMt + εt, βt = β + ηt, γt = Et-1[RMt], ρβ,γ > 0
E[Ri | RM]
0.00 0.02 0.04 0.06 0.08 0.10 0.12
0.00 0.02 0.04 0.06 0.08
RM
True
SLIDE 9
9
Overview Perspective on conditional asset-pricing tests A simple empirical test
SLIDE 10
10
Overview Perspective on conditional asset-pricing tests A simple empirical test Time-variation in betas / expected returns is too small to explain anomalies
SLIDE 11
11
Theory Excess returns: Rit, RMt No restriction on joint distribution of returns Notation γt = Et-1[RMt],
2 t
σ = vart-1(RMt), βt = covt-1(Rit, RMt) /
2 t
σ γ = E[RMt],
2 M
σ = var(RMt), βu = cov(Rit, RMt) /
2 M
σ β = E[βt]
SLIDE 12
12
Theory If conditional CAPM holds, what is αu ≡ E[Rit] – βu γ? Et-1[Rit] = βt γt
SLIDE 13
13
Theory If conditional CAPM holds, what is αu ≡ E[Rit] – βu γ? Et-1[Rit] = βt γt E[Rit] = β γ + cov(βt, γt)
SLIDE 14
14
Theory If conditional CAPM holds, what is αu ≡ E[Rit] – βu γ? Et-1[Rit] = βt γt E[Rit] = β γ + cov(βt, γt) ⇒ αu = γ(β – βu) + cov(βt, γt)
SLIDE 15
15
Theory If conditional CAPM holds, what is αu ≡ E[Rit] – βu γ? Et-1[Rit] = βt γt E[Rit] = β γ + cov(βt, γt) ⇒ αu = γ(β – βu) + cov(βt, γt) Conditional beta βu = β + ) , cov( 1 ] ) ( , cov[ 1 ) , cov(
2 t t 2 M 2 t t 2 M t t 2 M
σ β σ + γ − γ β σ + γ β σ γ
SLIDE 16
16
Theory If conditional CAPM holds, what is αu ≡ E[Rit] – βu γ? Et-1[Rit] = βt γt E[Rit] = β γ + cov(βt, γt) ⇒ αu = γ(β – βu) + cov(βt, γt) Conditional beta βu = β + ) , cov( 1 ] ) ( , cov[ 1 ) , cov(
2 t t 2 M 2 t t 2 M t t 2 M
σ β σ + γ − γ β σ + γ β σ γ Convexity Cubic Volatility
SLIDE 17
17
Theory If conditional CAPM holds, what is αu ≡ E[Rit] – βu γ? Et-1[Rit] = βt γt E[Rit] = β γ + cov(βt, γt) ⇒ αu = γ(β – βu) + cov(βt, γt) Conditional beta βu = β + ) , cov( 1 ] ) ( , cov[ 1 ) , cov(
2 t t 2 M 2 t t 2 M t t 2 M
σ β σ + γ − γ β σ + γ β σ γ Conditional alpha αu = ) , cov( ] ) ( , cov[ ) , cov( 1
2 t t 2 M 2 t t 2 M t t 2 M 2
σ β σ γ − γ − γ β σ γ − γ β σ γ −
SLIDE 18
18
Magnitude αu = ) , cov( ] ) ( , cov[ ) , cov( 1
2 t t 2 M 2 t t 2 M t t 2 M 2
σ β σ γ − γ − γ β σ γ − γ β σ γ −
SLIDE 19 19
Magnitude αu = ) , cov( ] ) ( , cov[ ) , cov( 1
2 t t 2 M 2 t t 2 M t t 2 M 2
σ β σ γ − γ − γ β σ γ − γ β σ γ −
2 M
σ ? 1964 – 2001: γ = 0.47%, σM = 4.5% ⇒ γ2 /
2 M
σ = 0.011
SLIDE 20 20
Magnitude αu = ) , cov( ] ) ( , cov[ ) , cov( 1
2 t t 2 M 2 t t 2 M t t 2 M 2
σ β σ γ − γ − γ β σ γ − γ β σ γ −
2 M
σ ? 1964 – 2001: γ = 0.47%, σM = 4.5% ⇒ γ2 /
2 M
σ = 0.011
Suppose γ ≈ 0.5% and 0.0% < γt < 1.0%. Then (γt – γ)2 is at most 0.0052 = 0.000025.
SLIDE 21 21
Magnitude αu = ) , cov( ] ) ( , cov[ ) , cov( 1
2 t t 2 M 2 t t 2 M t t 2 M 2
σ β σ γ − γ − γ β σ γ − γ β σ γ −
2 M
σ ? 1964 – 2001: γ = 0.47%, σM = 4.5% ⇒ γ2 /
2 M
σ = 0.011
Suppose γ ≈ 0.5% and 0.0% < γt < 1.0%. Then (γt – γ)2 is at most 0.0052 = 0.000025. αu ≈ ) , cov( ) , cov(
t t M t t 2 2
σ β σ γ − γ β
SLIDE 22
22
1: Constant volatility αu ≈ cov(βt, γt) = ρ σβ σγ
ρ = 0.6 σβ ρ = 1.0 σβ 0.3 0.5 0.7 0.3 0.5 0.7 Monthly alpha (%) Monthly alpha (%) σγ = 0.1 σγ = 0.1 0.2 0.2 0.3 0.3 0.4 0.4 0.5 0.5
SLIDE 23
23
1: Constant volatility αu ≈ cov(βt, γt) = ρ σβ σγ
ρ = 0.6 σβ ρ = 1.0 σβ 0.3 0.5 0.7 0.3 0.5 0.7 Monthly alpha (%) Monthly alpha (%) σγ = 0.1 σγ = 0.1 0.2 0.2 0.3 0.3 0.4 0.4 0.5 0.5
Economically large Evidence later Fama and French (1992, 1997)
SLIDE 24
24
1: Constant volatility αu ≈ cov(βt, γt) = ρ σβ σγ
ρ = 0.6 σβ ρ = 1.0 σβ 0.3 0.5 0.7 0.3 0.5 0.7 Monthly alpha (%) Monthly alpha (%) σγ = 0.1 σγ = 0.1 0.2 0.2 0.3 0.3 0.4 0.4 0.5 0.5
Economically large Evidence from predictive regressions Campbell and Cochrane (1999)
SLIDE 25
25
1: Constant volatility αu ≈ cov(βt, γt) = ρ σβ σγ
ρ = 0.6 σβ ρ = 1.0 σβ 0.3 0.5 0.7 0.3 0.5 0.7 Monthly alpha (%) Monthly alpha (%) σγ = 0.1 σγ = 0.1 0.2 0.2 0.3 0.3 0.4 0.4 0.5 0.5
Arbitrary
SLIDE 26
26
1: Constant volatility αu ≈ cov(βt, γt) = ρ σβ σγ
ρ = 0.6 σβ ρ = 1.0 σβ 0.3 0.5 0.7 0.3 0.5 0.7 Monthly alpha (%) Monthly alpha (%) σγ = 0.1 0.02 0.03 0.04 σγ = 0.1 0.03 0.05 0.07 0.2 0.04 0.06 0.08 0.2 0.06 0.10 0.14 0.3 0.05 0.09 0.12 0.3 0.09 0.15 0.21 0.4 0.07 0.12 0.17 0.4 0.12 0.20 0.28 0.5 0.09 0.15 0.21 0.5 0.15 0.25 0.35
SLIDE 27
27
1: Constant volatility αu ≈ cov(βt, γt) = ρ σβ σγ
ρ = 0.6 σβ ρ = 1.0 σβ 0.3 0.5 0.7 0.3 0.5 0.7 Monthly alpha (%) Monthly alpha (%) σγ = 0.1 0.02 0.03 0.04 σγ = 0.1 0.03 0.05 0.07 0.2 0.04 0.06 0.08 0.2 0.06 0.10 0.14 0.3 0.05 0.09 0.12 0.3 0.09 0.15 0.21 0.4 0.07 0.12 0.17 0.4 0.12 0.20 0.28 0.5 0.09 0.15 0.21 0.5 0.15 0.25 0.35
B/M portfolio: 0.59% Momentum portfolio: 1.01%
SLIDE 28 28
1: Constant volatility βt ~ N[1.0, 0.7], γt ~ N[0.5%, 0.5%], ρ = 1.0
E[Ri | RM]
0.00 0.02 0.04 0.06 0.08 0.10
0.00 0.02 0.04 0.06 0.08
RM
True
SLIDE 29
29
2: Time-varying volatility αu ≈ ) , cov( ) , cov(
2 t t 2 M t t
σ β σ γ − γ β Effects of time-varying γt and
2 t
σ offset (if they move together)
SLIDE 30
30
2: Time-varying volatility αu ≈ ) , cov( ) , cov(
2 t t 2 M t t
σ β σ γ − γ β Effects of time-varying γt and
2 t
σ offset (if they move together) Merton (1980): γt = λ
2 t
σ ) , cov(
t t 2 M 2 u
γ β σ σ ≈ α
γ
< cov(βt, γt)
SLIDE 31 31
2: Time-varying volatility αu ≈ ) , cov(
2 t t 2 M
σ β σ γ − = – γ ρ σβ σv (where vt =
2 t
σ /
2 M
σ )
ρ = 0.2 σβ ρ = 0.5 σβ 0.3 0.5 0.7 0.3 0.5 0.7 Alpha (%) Alpha (%) σv = 1.0
σv = 1.0
1.3
1.3
1.6
1.6
1.9
1.9
2.2
2.2
γ = 0.50
SLIDE 32
32
Testing the conditional CAPM Traditional tests Rit = αit + βit RMt + εit βit = bi0 + bi1 Z1,t-1 + bi2 Z2,t-1 + …
SLIDE 33
33
Testing the conditional CAPM Traditional tests Rit = αit + βit RMt + εit βit = bi0 + bi1 Z1,t-1 + bi2 Z2,t-1 + … Cochrane (2001) “Models such as the CAPM imply a conditional linear factor model with respect to investors’ information sets. The best we can hope to do is test implications conditioned on variables that we observe. Thus, a conditional factor model is not testable!”
SLIDE 34 34
Our tests Rit = αit + βit RMt + εit Short-window regressions
- Estimate αit, βit every month, quarter, half-year, or year
- Are conditional alphas zero?
SLIDE 35 35
Our tests Rit = αit + βit RMt + εit Short-window regressions
- Estimate αit, βit every month, quarter, half-year, or year
- Are conditional alphas zero?
- How volatile are betas?
- Do betas covary with the equity premium and variance?
SLIDE 36 36
Our tests Rit = αit + βit RMt + εit Short-window regressions
- Estimate αit, βit every month, quarter, half-year, or year
- Are conditional alphas zero?
- How volatile are betas?
- Do betas covary with the equity premium and variance?
SLIDE 37
37
Our tests Short-window regressions – betas
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1 61 121 181 241 301 361 421 481 541
Days
SLIDE 38 38
Our tests Rit = αit + βit RMt + εit Short-window regressions
- Estimate αit, βit every month, quarter, half-year, or year
- Are conditional alphas zero?
SLIDE 39 39
Our tests Rit = αit + βit RMt + εit Short-window regressions
- Estimate αit, βit every month, quarter, half-year, or year
- Are conditional alphas zero?
- Assumes only that beta is relatively slow moving
SLIDE 40 40
Our tests Rit = αit + βit RMt + εit Short-window regressions
- Estimate αit, βit every month, quarter, half-year, or year
- Are conditional alphas zero?
- Assumes only that beta is relatively slow moving
- Don’t need precise estimates of individual αit, βit
SLIDE 41 41
Our tests Rit = αit + βit RMt + εit Short-window regressions
- Estimate αit, βit every month, quarter, half-year, or year
- Are conditional alphas zero?
- Assumes only that beta is relatively slow moving
- Don’t need precise estimates of individual αit, βit
- Microstructure issues
SLIDE 42
42
Microstructure issue 1 Horizon effects (compounding) Daily alphas, betas ≠ monthly alphas, betas
SLIDE 43
43
Microstructure issue 1 Horizon effects (compounding) Daily alphas, betas ≠ monthly alphas, betas
N 2 M N 2 M N M N i N M i i
] R 1 [ E ] ) R 1 [( E ] R 1 [ E ] R 1 [ E )] R 1 )( R 1 [( E ) N ( + − + + + − + + = β
1.49 1.50 1.51 1.52
1 6 11 16 21 26 31 36 41 46 51 56 61
Days (N)
SLIDE 44
44
Microstructure issue 2 Thin trading / nonsynchronous prices Daily / weekly estimates of beta miss full covariance
SLIDE 45
45
Microstructure issue 2 Beta estimates, horizons from 1 to 45 days, 1964 – 2001
Small stocks Value stocks
0.6 0.8 1.0 1.2 1.4
1 5 9 13 17 21 25 29 33 37 41 45
Horizon (days)
SLIDE 46
46
Microstructure issue 2 Partial solution Use value-weighted portfolios and NYSE / Amex stocks Dimson (1979) betas: Ri,t = αi + βi0 RM,t + βi1 RM,t-1 + … + βik RM,t-k + εi,t βi = βi0 + βi1 + … + βik
SLIDE 47 47
Microstructure issue 2 Beta estimates
Ri,t = αi + βi0 RM,t + βi1 RM,t-1 + βi2 [(RM,t-2 + RM,t-3 + RM,t-4)/3] + εi,t
Ri,t = αi + βi0 RM,t + βi1 RM,t-1 + βi2 RM,t-2 + εi,t
Ri,t = αi + βi0 RM,t + βi1 RM,t-1 + εi,t
SLIDE 48
48
Data NYSE / Amex stocks, 1964 – 2001 VW portfolios 25 size-B/M portfolios (S, B, V, G) 10 momentum portfolios, 6-month returns (W, L)
SLIDE 49 49
Summary statistics, 1964 – 2001 Monthly, %
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Excess returns Avg. Day 0.57 0.49 0.08 0.32 0.81 0.49
0.87 0.97 Wk 0.63 0.50 0.13 0.37 0.84 0.47
0.91 0.95 Mon 0.71 0.50 0.21 0.41 0.88 0.47 0.01 0.91 0.90 Std err. Day 0.28 0.20 0.19 0.27 0.23 0.13 0.33 0.28 0.26 Wk 0.26 0.18 0.18 0.26 0.22 0.12 0.30 0.26 0.25 Mon 0.34 0.19 0.23 0.30 0.26 0.16 0.35 0.28 0.27
SLIDE 50 50
Summary statistics, 1964 – 2001
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Unconditional alphas Est. Day 0.09 0.10
0.39 0.60
0.35 0.99 Wk 0.05 0.10
0.37 0.59
0.37 1.03 Mon 0.07 0.11
0.39 0.59
0.38 1.01 Std err. Day 0.15 0.06 0.17 0.10 0.12 0.12 0.18 0.13 0.26 Wk 0.14 0.06 0.16 0.09 0.11 0.11 0.17 0.12 0.25 Mon 0.18 0.07 0.20 0.11 0.13 0.14 0.19 0.13 0.28 Unconditional betas Est. Day 1.07 0.87 0.20 1.18 0.94 -0.25 1.22 1.17
Wk 1.25 0.86 0.39 1.27 1.03 -0.24 1.33 1.16
Mon 1.34 0.83 0.51 1.30 1.05 -0.25 1.36 1.14
Std err. Day 0.03 0.01 0.03 0.02 0.03 0.02 0.03 0.02 0.05 Wk 0.03 0.01 0.04 0.02 0.03 0.03 0.04 0.03 0.06 Mon 0.05 0.02 0.06 0.03 0.04 0.04 0.06 0.04 0.08
SLIDE 51
51
Test Are conditional alphas zero?
SLIDE 52
52
Test Are conditional alphas zero? Tests based on the time series of short-window αit Fama-MacBeth approach
SLIDE 53
53
Test Are conditional alphas zero? Tests based on the time series of short-window αit Fama-MacBeth approach Four versions of the short-window regressions Quarterly (daily returns) Semiannually (daily and weekly returns) Annually (monthly returns)
SLIDE 54 54
Conditional CAPM, 1964 – 2001
Conditional vs. unconditional alphas (%)
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Unconditional alphas Day 0.09 0.10
0.39 0.60
0.35 0.99 Wk 0.05 0.10
0.37 0.59
0.37 1.03 Month 0.07 0.11
0.39 0.59
0.38 1.01 Average conditional alpha Quarterly 0.42 0.00 0.42
0.49 0.50
0.55 1.33 Semi 1 0.26 0.00 0.26
0.40 0.47
0.39 0.99 Semi 2 0.16 0.01 0.15
0.36 0.48
0.53 1.37 Annual
0.08
0.32 0.53
0.21 0.77
SLIDE 55 55
Conditional CAPM, 1964 – 2001
Conditional vs. unconditional alphas (%)
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Unconditional alphas Day 0.09 0.10
0.39 0.60
0.35 0.99 Wk 0.05 0.10
0.37 0.59
0.37 1.03 Month 0.07 0.11
0.39 0.59
0.38 1.01 Average conditional alpha Quarterly 0.42 0.00 0.42
0.49 0.50
0.55 1.33 Semi 1 0.26 0.00 0.26
0.40 0.47
0.39 0.99 Semi 2 0.16 0.01 0.15
0.36 0.48
0.53 1.37 Annual
0.08
0.32 0.53
0.21 0.77
SLIDE 56 56
Conditional CAPM, 1964 – 2001
Conditional alphas and standard errors
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Estimate Quarterly 0.42 0.00 0.42
0.49 0.50
0.55 1.33 Semi 1 0.26 0.00 0.26
0.40 0.47
0.39 0.99 Semi 2 0.16 0.01 0.15
0.36 0.48
0.53 1.37 Annual
0.08
0.32 0.53
0.21 0.77 Standard error Quarterly 0.20 0.06 0.22 0.12 0.14 0.14 0.20 0.13 0.26 Semi 1 0.21 0.06 0.23 0.12 0.14 0.15 0.19 0.14 0.25 Semi 2 0.21 0.06 0.23 0.14 0.15 0.16 0.20 0.15 0.27 Annual 0.26 0.07 0.29 0.16 0.17 0.14 0.21 0.17 0.29
SLIDE 57
57
Exploring the results Time-varying betas have a small impact on alphas Why? How volatile are betas? Do betas covary with business conditions? Do betas covary with γt and
2 t
σ ?
SLIDE 58 58
Conditional betas (semiannual, daily returns), 1964 – 2001 Small minus Big
0.0 0.3 0.6 0.9 1.2
1964.2 1971.2 1978.2 1985.2 1992.2 1999.2
SLIDE 59 59
Conditional betas (semiannual, daily returns), 1964 – 2001 Value minus Growth
0.0 0.2 0.4 0.7
1964.2 1971.2 1978.2 1985.2 1992.2 1999.2
SLIDE 60 60
Conditional betas (semiannual, daily returns), 1964 – 2001 Winner minus Losers
0.0 0.5 1.1 1.6 2.2
1964.2 1971.2 1978.2 1985.2 1992.2 1999.2
SLIDE 61 61
Conditional betas, 1964 – 2001
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Unconditional betas Day 1.07 0.87 0.20 1.18 0.94 -0.25 1.22 1.17
Wk 1.25 0.86 0.39 1.27 1.03 -0.24 1.33 1.16
Month 1.34 0.83 0.51 1.30 1.05 -0.25 1.36 1.14
Average conditional betas Quarterly 1.03 0.93 0.10 1.17 0.98 -0.19 1.19 1.24 0.05 Semi 1 1.07 0.93 0.14 1.19 0.99 -0.20 1.20 1.24 0.05 Semi 2 1.23 0.91 0.32 1.25 1.06 -0.19 1.33 1.19
Annual 1.49 0.83 0.66 1.36 1.17 -0.19 1.38 1.24
Implied std deviation of true betas Quarterly 0.32 0.13 0.33 0.19 0.28 0.25 0.36 0.33 0.63 Semi 1 0.29 0.12 0.30 0.18 0.28 0.24 0.30 0.30 0.55 Semi 2 0.31 0.10 0.32 0.16 0.31 0.29 0.36 0.32 0.62 Annual 0.35
0.04 0.37 0.19 0.19 0.29 0.52
SLIDE 62 62
Conditional betas, 1964 – 2001
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Unconditional betas Day 1.07 0.87 0.20 1.18 0.94 -0.25 1.22 1.17
Wk 1.25 0.86 0.39 1.27 1.03 -0.24 1.33 1.16
Month 1.34 0.83 0.51 1.30 1.05 -0.25 1.36 1.14
Average conditional betas Quarterly 1.03 0.93 0.10 1.17 0.98 -0.19 1.19 1.24 0.05 Semi 1 1.07 0.93 0.14 1.19 0.99 -0.20 1.20 1.24 0.05 Semi 2 1.23 0.91 0.32 1.25 1.06 -0.19 1.33 1.19
Annual 1.49 0.83 0.66 1.36 1.17 -0.19 1.38 1.24
Implied std deviation of true betas Quarterly 0.32 0.13 0.33 0.19 0.28 0.25 0.36 0.33 0.63 Semi 1 0.29 0.12 0.30 0.18 0.28 0.24 0.30 0.30 0.55 Semi 2 0.31 0.10 0.32 0.16 0.31 0.29 0.36 0.32 0.62 Annual 0.35
0.04 0.37 0.19 0.19 0.29 0.52
SLIDE 63 63
Conditional betas, 1964 – 2001
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Unconditional betas Day 1.07 0.87 0.20 1.18 0.94 -0.25 1.22 1.17
Wk 1.25 0.86 0.39 1.27 1.03 -0.24 1.33 1.16
Month 1.34 0.83 0.51 1.30 1.05 -0.25 1.36 1.14
Average conditional betas Quarterly 1.03 0.93 0.10 1.17 0.98 -0.19 1.19 1.24 0.05 Semi 1 1.07 0.93 0.14 1.19 0.99 -0.20 1.20 1.24 0.05 Semi 2 1.23 0.91 0.32 1.25 1.06 -0.19 1.33 1.19
Annual 1.49 0.83 0.66 1.36 1.17 -0.19 1.38 1.24
Implied std deviation of true betas Quarterly 0.32 0.13 0.33 0.19 0.28 0.25 0.36 0.33 0.63 Semi 1 0.29 0.12 0.30 0.18 0.28 0.24 0.30 0.30 0.55 Semi 2 0.31 0.10 0.32 0.16 0.31 0.29 0.36 0.32 0.62 Annual 0.35
0.04 0.37 0.19 0.19 0.29 0.52
SLIDE 64 64
Conditional betas, 1964 – 2001
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Unconditional betas Day 1.07 0.87 0.20 1.18 0.94 -0.25 1.22 1.17
Wk 1.25 0.86 0.39 1.27 1.03 -0.24 1.33 1.16
Month 1.34 0.83 0.51 1.30 1.05 -0.25 1.36 1.14
Average conditional betas Quarterly 1.03 0.93 0.10 1.17 0.98 -0.19 1.19 1.24 0.05 Semi 1 1.07 0.93 0.14 1.19 0.99 -0.20 1.20 1.24 0.05 Semi 2 1.23 0.91 0.32 1.25 1.06 -0.19 1.33 1.19
Annual 1.49 0.83 0.66 1.36 1.17 -0.19 1.38 1.24
Implied std deviation of true betas Quarterly 0.32 0.13 0.33 0.19 0.28 0.25 0.36 0.33 0.63 Semi 1 0.29 0.12 0.30 0.18 0.28 0.24 0.30 0.30 0.55 Semi 2 0.31 0.10 0.32 0.16 0.31 0.29 0.36 0.32 0.62 Annual 0.35
0.04 0.37 0.19 0.19 0.29 0.52
bt = βt + et → var(βt) = var(bt) – var(et)
SLIDE 65
65
Test Do betas covary with business conditions? Do betas covary with γt and
2 t
σ ?
SLIDE 66
66
Test Do betas covary with business conditions? Market returns (6 months) Tbill rate Dividend yield Term premium CAY Lagged beta
SLIDE 67 67
Conditional betas, 1964 – 2001
Correlation between betas and state variables
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L βt-1 0.55 0.68 0.43 0.58 0.67 0.51 0.30 0.45 0.37 RM,-6
0.00 0.14
0.47 0.56 TBILL
0.11
0.15
0.14
DY 0.22 0.64
0.37 0.40 0.18 0.13
TERM
0.19
0.01 0.10
CAY
0.50
0.17 0.20 0.09
- 0.09
- 0.10
- Std. error ≈ 0.116 if no autocorrelation
SLIDE 68 68
Predicting conditional betas, 1964 – 2001
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Slope estimate βt-1 0.12 0.05 0.11 0.10 0.12 0.08 0.10 0.15 0.22 RM,-6 0.05
0.04 0.02 0.04 0.04
0.20 0.39 TBILL
- 0.13
- 0.02
- 0.11
- 0.03
- 0.14
- 0.13
0.09
DY 0.14 0.05 0.09 0.06 0.16 0.10
0.11 0.19 TERM
0.00
0.07
CAY
0.02
0.03 0.00
t-statistic βt-1 3.53 3.99 2.83 4.24 3.88 2.62 3.03 5.31 4.49 RM,-6 1.52
1.17 0.73 1.58 1.41
7.25 7.63 TBILL
- 2.56
- 1.39
- 2.09
- 1.06
- 3.19
- 2.98
1.79
DY 2.82 3.05 1.74 2.10 3.64 2.65
2.87 2.65 TERM
- 2.40
- 0.25
- 2.21
- 0.81
- 2.40
- 1.99
1.60
CAY
1.86
0.98 0.07
Adj R2 0.37 0.60 0.26 0.34 0.52 0.32 0.35 0.56 0.53
SLIDE 69 69
Predicting conditional betas, 1964 – 2001
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Slope estimate βt-1 0.12 0.05 0.11 0.10 0.12 0.08 0.10 0.15 0.22 RM,-6 0.05
0.04 0.02 0.04 0.04
0.20 0.39 TBILL
- 0.13
- 0.02
- 0.11
- 0.03
- 0.14
- 0.13
0.09
DY 0.14 0.05 0.09 0.06 0.16 0.10
0.11 0.19 TERM
0.00
0.07
CAY
0.02
0.03 0.00
t-statistic βt-1 3.53 3.99 2.83 4.24 3.88 2.62 3.03 5.31 4.49 RM,-6 1.52
1.17 0.73 1.58 1.41
7.25 7.63 TBILL
- 2.56
- 1.39
- 2.09
- 1.06
- 3.19
- 2.98
1.79
DY 2.82 3.05 1.74 2.10 3.64 2.65
2.87 2.65 TERM
- 2.40
- 0.25
- 2.21
- 0.81
- 2.40
- 1.99
1.60
CAY
1.86
0.98 0.07
Adj R2 0.37 0.60 0.26 0.34 0.52 0.32 0.35 0.56 0.53
SLIDE 70
70
Test Does beta covary with γt? What is the implied alpha αu ≈ cov(βt, γt)? Two estimates (i) cov(bt, RMt) = cov(βt + et, γt + st) = cov(βt, γt) (ii) cov(
* t
b , RMt) = cov(
* t
b , γt)
SLIDE 71 71
Beta and the market risk premium, 1964 – 2001
Covariance between estimated betas and market returns Implied αu (%)
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Estimate Quarterly
0.07
0.09 0.16
Semi 1
0.07
0.11
Semi 2
0.07
0.07 0.15
Annual 0.06 0.03 0.03
0.01 0.04
0.11 0.20 Standard error Quarterly 0.08 0.03 0.08 0.05 0.07 0.06 0.09 0.08 0.16 Semi 1 0.07 0.03 0.07 0.04 0.07 0.06 0.08 0.07 0.13 Semi 2 0.08 0.03 0.08 0.04 0.08 0.07 0.10 0.08 0.15 Annual 0.12 0.03 0.13 0.06 0.10 0.09 0.12 0.10 0.19
SLIDE 72 72
Beta and the market risk premium, 1964 – 2001
Covariance between predicted betas and market returns Implied αu (%)
Size B/M Momentum Small Big S-B Grwth Value V-G Losrs Winrs W-L Estimate Quarterly
0.04
0.02 0.06
Semi 1
0.03
0.01 0.05
Semi 2
0.02
0.00
0.00 0.07
Annual 0.03 0.01 0.02 0.00 0.01 0.03 0.05
Standard error Quarterly 0.04 0.02 0.04 0.03 0.05 0.04 0.05 0.06 0.10 Semi 1 0.05 0.02 0.04 0.03 0.05 0.04 0.05 0.06 0.10 Semi 2 0.04 0.02 0.03 0.02 0.05 0.04 0.06 0.05 0.10 Annual 0.05 0.02 0.05 0.03 0.06 0.04 0.06 0.05 0.09
SLIDE 73
73
Final comments Consumption CAPM Other studies Jagannathan and Wang (1996) Lettau and Ludvigson (2001) Santos and Veronesi (2004) Lustig and Van Nieuwerburgh (2004)
SLIDE 74
74
Other studies Approach Et-1[Rt] = βt γt ⇒ E[R] = β γ + cov(βt, γt)
SLIDE 75
75
Other studies Approach Et-1[Rt] = βt γt ⇒ E[R] = β γ + cov(βt, γt) Fama-MacBeth regressions: E[R] = θ0 + θ1 β + θ2 cov(βt, γt)
SLIDE 76
76
Other studies Approach Et-1[Rt] = βt γt ⇒ E[R] = β γ + cov(βt, γt) Fama-MacBeth regressions: E[R] = θ0 + θ1 β + θ2 cov(βt, γt) Restrictions on θ0, θ1, and θ2 are ignored Estimates of θ2 seem to be much larger than 1
SLIDE 77
77
Other studies Approach Et-1[Rt] = βt γt ⇒ E[R] = β γ + cov(βt, γt) Fama-MacBeth regressions: E[R] = θ0 + θ1 β + θ2 cov(βt, γt) Restrictions on θ0, θ1, and θ2 are ignored Estimates of θ2 seem to be much larger than 1 Cross-sectional R2s, with restrictions, aren’t meaningful Easy to find high R2s using size-B/M portfolios Simulations 90% confidence interval = [0.12, 0.72]
SLIDE 78
78
Summary Conditioning relatively unimportant for asset-pricing tests, both in principle and in practice Betas vary significantly over time Conditional alphas are close to unconditional alphas