Asset pricing models look for factors that provide information about return in an effort to explain the cross-section of asset return. The component or factors in a particular model describe the cross-section of expected returns, according to empirical testing of these models.
Frequently. Although there are alternative methods for assessing asset pricing models, the Fama and MacBeth (1973) technique is popular because it tackles the issue of cross-sectional correlation. This study uses the Fama-MacBeth approach to analyze the CAPM and the Fama-French three-factor model for 100 Fama-French stock portfolios based on size and book-to-market equity (BE/ME). We demonstrate that when it comes to describing the average return cross-section from January 1927 to December 2023, the Fama-French three-factor model performs better than the CAPM.
5.1. Empirical Analysis
According to CAPM, market beta and expected return on assets are proportionate. It displays a linear correlation between beta (
β) and risk premium (
R −
Rf). If this estimate is accurate, the pricing error (
α) should be equal to zero.
The average monthly excess returns for 100 Fama-French portfolios are shown in
Table 1. These investments' average excess returns per month fall between 0.30% and 1.16%. Additionally, except for the lowest-BE/ME quintile, portfolios of all sizes often have higher average returns. Similarly, the average returns of the portfolios with the highest BE/ME ratio are consistently higher than those of the portfolios with the lowest BE/ME ratio. The BE/ME portfolios with the best and lowest returns had monthly average return differences ranging from 0.23% to 0.86%. If the CAPM is effective on 100 portfolios, then market betas should be able to capture these distinct patterns of systematic variance in returns.
Table 1 displays the CAPM time-series regression estimates. Although market betas are higher for tiny stocks, they are significantly lower for high-BE/ME stocks. It ignores variance in BE/ME-caused returns but implies that betas can explain some of the size fluctuation. Alphas for the smallest-size portfolios beat those for the largest by 0.15% to 0.46% every month, with the exception of the lowest-BE/ME quintile. Additionally, the 18 portfolios' strong alphas show that the CAPM leaves an acceptable return on 100 portfolios that is inexplicable. The joint test of alphas, on the other hand, would provide a trustworthy statistic to assess the significance of price inaccuracy.
3-D bar charts of average excess returns, betas, and alphas are shown in
Figure 1. Big stocks yield a poorer return, and low-BE/ME portfolios perform worse than high-BE/ME portfolios.
Figure 1(a) shows the comparison with small stocks. Beta should gradually rise from big stock to small stock portfolios and from low-BE/ME portfolios to high-BE/ME portfolios if market beta and return are linearly correlated. It is difficult to observe this intended movement of beta since beta is insufficient to explain the cross-section of returns, as shown in
Figure 1(b). The fact that most of the alphas in
Figure 1(c) are not zero further indicates that pricing error in CAPM is not insignificant.
Furthermore,
Figure 2 shows the CAPM model's goodness-of-fit using a scatter plot of the actual average return and the CAPM-predicted return for 100 portfolios. We cannot assert that sensitivity to market volatility can adequately explain the cross-section of average returns on stock portfolios since the majority of the filled circles fall beyond the 45-degree line. The CAPM is unable to adequately explain the shared variation in average return since the alphas for at least 18 portfolios deviate from 0. According to Banz (1981) and Basu (1983), it implies that there are other elements that are important for asset prices.
The Fama-French three-factor model proposes that three factors—size (
SMB), book-to-market equity (
HML), and overall market (
Rm −
Rf)—are responsible for variations in average stock returns. If these three factors are adequate to capture common variance in stock returns, then the intercept (
α) in the time-series regression of excess return on these three factors should be equal to 0.
Table 2 displays the t-statistics, alphas, and coefficients from the three-factor Fama-French time-series regression for Fama-French 100 portfolios. The average excess returns of smaller portfolios are frequently higher than those of larger portfolios, while the average excess returns of high-BE/ME portfolios are higher than those of low-BE/ME portfolios.
However, because the relationship between average return and βs for 100 portfolios appears to be flat, market β does not account for this widespread variation in returns. In contrast, coefficients on SMB and HML tend to offer a strong explanation for stock performance variance for these portfolios. In each size quintile, the coefficients on HML, which stand for return for book-to-market equity, increase monotonically from the low- to high BE/ME quintiles. In each BE/ME quintile, the slopes on SMB, the mimicking return for the size component, also climb monotonically, moving from high negative values for the quintiles with the largest size to high positive values for the quintiles of the lowest size. Both HML and SMB clearly capture the systematic volatility in stock returns caused by size and book-to-market equity, which market beta overlooks.
Additionally, alphas for 100 portfolios in three-factor regression range from -0.12% to 0.17% per month. Only six of the 100 alphas depart from 0 by more than 0.14% per month, suggesting that Rm – Rf, SMB, and HML more accurately depict shared variance in stock returns.
The coefficients on
Rm –
Rf,
HML, and
SMB are shown in 3-D plots in
Figure 3. Although portfolios with higher average returns should have higher market beta,
Figure 3(a) does not show this relationship for all quintiles. On the other hand,
Figure 3(b) clearly shows a monotonic rise in BE/ME slopes from low- to high-BE/ME (x-axis) portfolios. In relation to book-to-market equity, it suggests that
HML records systematic variance in stock returns that the market and SMB do not. Subsequently,
Figure 3(c) shows a steady decline in size-related slopes from small- to big-size portfolios (y-axis). Usually,
SMB reflects the variation in stock returns in response to size that cannot be explained by market and book-to-market equity.
Figure 3 illustrates how the expected returns from regression on the Fama-French three-factor model are more accurate when both
HML and
SMB accurately capture typical variation in average returns of portfolios. The Fama-French three-factor model's predicted returns for 100 portfolios closely match the actual returns. Furthermore, the majority of the portfolios' low standard errors of alphas demonstrate the strong explanatory power of the variables in the Fama-French three-factor model for describing average returns.
Figure 4.
The relationship between the monthly average excess returns (y-axis) on Fama-French 100 portfolios and the expected excess returns (x-axis) is shown in a scatterplot. Each plot's error bar shows the standard errors of the corresponding alphas. The majority of the filled circles have relatively low standard errors of alphas and sit near the 45° (thick purple) line, indicating that the French and Fama three-factor models have a good ability to explain the cross-section of average returns on stock portfolios.
Figure 4.
The relationship between the monthly average excess returns (y-axis) on Fama-French 100 portfolios and the expected excess returns (x-axis) is shown in a scatterplot. Each plot's error bar shows the standard errors of the corresponding alphas. The majority of the filled circles have relatively low standard errors of alphas and sit near the 45° (thick purple) line, indicating that the French and Fama three-factor models have a good ability to explain the cross-section of average returns on stock portfolios.
5.2. Comparison Among Three Models
The drawback of the CAPM that market beta cannot account for all systematic hazards, which define a cross-section of stock return, is addressed by the Fama-French three-factor model. As an alternative, we build a two-factor model using
Rm –
Rf and
HML, presuming that beta accounts for size-related variation. For comparison,
Table 3 lists each model's mean
and root mean square alpha.
Regression intercepts are used to compare asset pricing models according to a rigorous criterion (Fama and French, 1993). The Fama-French three-factor model has the lowest root mean square (RMS) alpha, which is even lower than half of the RMS alpha of the CAPM. Furthermore, the two-factor model's RMS alpha is lower than the CAPM's. It illustrates how the Fama-French three-factor model performs better than both the CAPM and the two-factor model. RMS alpha ignores the residual distribution, but the Wald or Gibbons-Ross-Shanken tests do.
indicates the extent to which model parameters may be responsible for the typical variation in average returns. As anticipated, the average values of these models agree with the RMS alpha values. Out of the three models, the Fama-French three-factor model has the greatest average value (0.636902). In comparison to the two-factor model and the CAPM, it implies that this model has the best explanatory power for explaining variations in the average return across 100 portfolios. However, the appropriate statistic for comparing models would be adjusted for degrees of freedom.
5.3. Factor Premium
Table 4 presents the slopes of a single cross-sectional regression, indicating that the risk premium for size and book-to-market equity is not zero over the years 1927–2023. The average stock return over the same period cannot be explained by market beta, and the slope for the slope for the slope for the slope for
β is negative.
Nevertheless, single cross-sectional regression standard errors have limitations. First of all, because cross-sectional correlation and serial correlation in error terms are not adjusted, these are often underestimated. Second, betas' time-varying nature is not acknowledged.
Last but not least, heteroskedasticity weakens OLS standard errors (Petersen, 2009). The updated cross-sectional regression estimates utilizing the Fama-MacBeth technique, which fixes the aforementioned issues, are shown in
Table 5.
Compared to OLS regression, Fama-MacBeth regression produces predicted slopes that are lower. Despite the fact that all slopes in the Fama-MacBeth regression have similar signs, the explanatory power of size stops for smaller slopes and larger standard errors. This outcome runs counter to what Fama and French (1992) found. Moreover, the negative slope of the market beta cannot account for average stock returns. However, book-to-market equity alone has a t-statistic of 7.7234.3 and an average risk premium of 0.9229%. This is because high BE/ME equities typically have continuously low earnings that are eventually reversed, according to Fama and French (1995). However, Lakonishok, Shleifer, and Vishny (1994) attribute this risk premium to mispricing. However, Fama-Macbeth regression risk premium estimates are not objective, according to Jagadeesh et al. (2019).