This lecture is mainly based the following textbooks:
Study review and practice: I strongly recommend using Prof. Henrique Castro (FGV-EAESP) materials. Below you can find the links to the corresponding exercises related to this lecture:
\(\rightarrow\) For coding replications, whenever applicable, please follow this page or hover on the specific slides with coding chunks.
Determining how much to expect an asset to reward investors is tied to portfolio choices
The required return is the expected return that is necessary to compensate for the risk investment \(i\) will contribute to the portfolio:
\[ \small E[R_i] > R_f + \beta_i^P \times (E[R_p] - R_f) \]
Once we can identify the efficient portfolio, we can compute the expected return of any security based on its beta with the efficient portfolio according to the equation just shown
However, we face a practical issue: in order to identify the efficient portfolio we must know the expected returns (\(E[\cdot]\)), volatilities (\(\sigma\)), and correlations between all securities
To answer this question, we’ll look at the Capital Asset Pricing Model - also known as CAPM:
As we’ll see throughout the lecture, CAPM is very practical and straightforward to implement, and the the CAPM-based approach is very robust
It imposes a disciplined process on managers to identify the cost of capital
It makes the capital budgeting process less subject to managerial manipulation than if managers could set project costs of capital (i.e., the opportunity cost for the firm’s equity) without clear justification
It is often the model many investors use to evaluate risk
All in all, it gets managers to think about risk in the correct way: instead of thinking about total risk, the CAPM shows us that we only the market risk (non-diversifiable) should be the concern
There are basically three simplifying assumptions around investor behavior that the CAPM establishes:
Investors can buy and sell all securities at competitive market prices without incurring taxes or transactions costs can borrow and lend at the risk-free interest rate
Investors hold only efficient portfolios of traded securities.
Investors have homogeneous expectations regarding the volatilities, correlations, and expected returns of securities. There is no information asymmetry.
With these assumptions, we are able to identify the efficient portfolio without having knowledge of the expected returns, volatilities, and correlations between all available investments
There are basically three simplifying assumptions around investor behavior that the CAPM establishes:
Investors can buy and sell all securities at competitive market prices without incurring taxes or transactions costs can borrow and lend at the risk-free interest rate
Investors hold only efficient portfolios of traded securities.
Investors have homogeneous expectations regarding the volatilities, correlations, and expected returns of securities. There is no information asymmetry.
With these assumptions, we are able to identify the efficient portfolio without having knowledge of the expected returns, volatilities, and correlations between all available investments
Assumption I
Investors can buy and sell all securities at competitive market prices (without incurring taxes or transactions costs) and can borrow and lend at the risk-free interest rate
Assumption II
Investors hold only efficient portfolios of traded securities—portfolios that yield the maximum expected return for a given level of volatility. All in all, for a given level of volatility assumed, an investor will always select the portfolio with the highest risk \(\times\) return relationship
This assumption states that all investors behave so as to choose the portfolio with the highest return for a given level of risk that they are willing to accept
As we saw, investors will seek to choose a given portfolio \(P\) such that has the highest Sharpe Ratio - which we called the tangent portfolio
Although risk preferences may change, investors will seek to combine a risky portfolio \(P\) with the risk-free rate so as to adjust for their preferences:
Assumption III
Investors have homogeneous expectations regarding the volatilities, correlations, and expected returns of securities.
Plausibly, there are many investors in the world, and each may have his or her own estimates of the volatilities, correlations, and expected returns of the available securities…
But investors don’t come up with these estimates arbitrarily:
\(\rightarrow\) As a consequence, it is not unreasonable to consider a special case in which all investors have the same estimates concerning future investments and returns
Think about your simplifying assumptions now…
If these are valid, under the CAPM assumptions, we can identify the efficient portfolio: it is equal to the market portfolio!
A Market Portfolio contains all traded securities in a economy according to their shares relative to the total!
When the CAPM assumptions hold, the market portfolio is the efficient portfolio, so the tangent portfolio that we discussed before is actually the market portfolio
The tangent line goes that through the market portfolio is called the Capital Market Line (CML):
Therefore, investors should always choose a portfolio on the Capital Market Line, by holding some combination of the risk-free security and the market portfolio
We can now identify the efficient portfolio: it is equal to the market portfolio
What does that mean for us in terms of determining expected equity returns? Recall that, from our previous class, the required return for a given stock \(i\) should be:
\[ \small E[R_i] > R_f + \beta_i^P \times (E[R_p] - R_f) \]
\[ \small E[R_i] = R_f + \beta_i^M \times (E[R_m] - R_f) \]
\[ \small E[R_i] = \underbrace{R_f + \beta_i^M \times (E[R_m] - R_f)}_{\text{This is a 1st order equation: }a+bx} \]
This relationship has also a name: the Security Market Line (SML). It is the line along which all individual securities should lie when plotted according to their expected return and \(\beta\)
\(\rightarrow\) Therefore, the distance of each stock to the right of the capital market line must be due to its diversifiable risk!
Because the security market line applies to all tradable investment opportunities, we can apply it to portfolios as well
How can we find the \(\beta\) of a full portfolio of assets? In order to see that, assume that you have several assets \(i\) in portfolio \(P\)
Thus, the return of the portfolio can be writen as \(R_p=\sum_{i}x_i R_i\), where \(x_i\) is the weight of each asset \(i\) in the portfolio
The \(\beta\) of this “asset” is then:
\[ \small \beta_{p}=\dfrac{Cov(R_p,R_m)}{\sigma^2_m}=\dfrac{Cov(\sum_{i}x_i R_i,R_m)}{\sigma^2_m}=\sum_i x_i\dfrac{Cov(R_i,R_m)}{\sigma^2_m}=\sum_i x_i\times \beta_i \] \(\rightarrow\) Therefore, the \(\beta\) of a portfolio is simply the weighted average of the indidivual betas!
Based on the CAPM model we’ve just seen, the cost of capital of any investment opportunity equals the expected return of the available investments with the same beta (those that are along the Capital Market Line):
You can know use this rationale to estimate how much an investor should need to earn in order to invest in a given stock \(i\):
\[R_i = R_f + \beta \times (E[R_m] - R_f)\]
\[R_{DIS}=3\%+1.29 \times (8\%−3\%) = 3\% + 6.45\% =9.45\%\]
\[R_{GMG}=3\%+0.55 \times(8\%−3\%)=3\%+2.75\%=5.75\%\]
\(\rightarrow\) Because market risk cannot be diversified, it is the market risk that determines the cost of capital. Therefore, DIS has a higher cost of equity capital than CMG, even though it is less volatile
Ok, now you now the dynamics behind the pricing of securities under the CAPM
However, no one really told you from where the numbers came from
Recall that, under the CAPM, we need to have estimates related to the market portfolio:
We will proceed by understanding each of these components and how to get estimates for them
First and foremost, what is the definition of a market portfolio? It is the total supply of securities, with the proportions of each security corresponding to the proportion of the total market that each security represents
Thus, the market portfolio contains more of the largest stocks and less of the smallest stocks. In order to see that, note that the market capitalization of one firm is simply the total market value of a firm’s outstanding shares:
\[\small MV_i = \text{# of shares outstanding} \times \text{Price per share} = N_i \times P_i\]
\[\small x_i = \frac{MV_i}{Total\; MV}= \frac{MV_i}{\sum{MV}}\]
Caution: indexes like the S&P500 and Ibovespa are not considered the market portfolio, but rather, they are proxies for the market portfolios - in other words, they are reasonable approximations of the market portfolio for a given set universe of securities
The first ingredient of CAPM is risk-free rate, which is the interest rate that investors can earn while having zero to limited volatility
Suggestions on how to pick the Risk-Free (\(R_f\)) rate to be used:
Often, we use a short-term risk-free rate to evaluate a short-term investment, and a long-term rate when evaluating a long-term investment
Another component of the Cost of Equity is the difference between \(E[R_m]\) and \(R_f\) (the market risk premium)
Ways to estimate the market risk premium:
When estimating the Cost of Equity, using historical data has two problems:
An alternative is to use a “discount rate” that is consistent with the current level of the market index in consideration: assume that, for a given firm \(i\), current prices can be modeled as future dividends (Gordon model). If that is true, then we have that:
\[ P_i=\dfrac{D_1}{r-g}\rightarrow r = \dfrac{D_1}{P_i}+g\equiv \text{Dividend Yield}+ \text{Growth rate on Dividends} \]
\[ R_m = \text{Dividend yield} + \text{Growth Rate on Dividends}= 2\% + 6\% = 8\% \]
While this model is highly inaccurate for an individual firm, the assumption of constant expected growth is more reasonable when considering the overall market
Following such methods, researchers generally report estimates in the 3%–5% range for the future equity risk premium
As of now, you were able to get a sense on how to get reasonable estimates for \(R_f\) and the Market Risk Premium, \(E[R_m]-R_f\)
All that is left is to estimate the stocks’s sensitivity to the returns of the market portfolio, \(\beta\). Recall that, a new asset \(i\) should be enhance the performance of a portfolio if:
\[ \small \underbrace{\frac{E[R_i] - R_f}{\sigma_{i} \times Corr(R_i,R_m)}}_{\text{Sharpe Ratio of } i} > \underbrace{\frac{E[R_m] - R_f}{\sigma_{m}}}_{\text{Sharpe Ratio of Market}} \]
\[ \small R_i - R_f = \underbrace{\frac{\sigma_{i} \times corr(R_i,R_m)}{\sigma_{m}}}_{\beta^M_i} \times (E[R_m] - R_f) \]
\[ \small (R_i - R_f)=\frac{\sigma_{i} \times Cov(R_i,R_m)}{\sigma_i \sigma_m\sigma_{m}} \times (E[R_p] - R_f)\rightarrow (R_i - R_f)= \underbrace{\frac{Cov(R_i,R_m)}{\sigma^2_m}}_{\text{OLS formula for slope}}\times (E[R_p] - R_f) \]
\[ \small (R_i - R_f) = \alpha_i + \beta_i \times (R_m - R_f) + \epsilon_i \]
\[ \small (R_i - R_f) = \alpha_i + \beta_i \times (R_m - R_f) + \epsilon_i \]
\(\alpha_i\) is the constant term. It measures the historical performance of the security relative to the expected return predicted by the security market line
It is the distance that the stock’s average return is above or below the SML. Thus, we can say \(\alpha_i\) is a risk-adjusted measure of the stock’s historical performance.
According to the CAPM, \(\alpha_i\) should not be significantly different from zero
Portfolio | Weight | Volatility (\(\sigma\)) | Correlation with M |
---|---|---|---|
HEC Corp | 0.21 | 13% | 0.42 |
Green Midget | 0.31 | 20% | 0.68 |
Alive And Well | 0.48 | 12% | 0.54 |
\[E[R_i]=r_f + β_i (E[R_M] −R_f) =2\% + 0.65 (12\% − 2\%) = 8.5\%\]
\[E[R_i]=r_f + β_i (E[R_M] −R_f) = 2\% + 0.95 (12\% − 2\%) = 11.5\%\]
\(\rightarrow\) Therefore, the range for the expected returns from Tikyberd is \([8.5\%,11.5\%]\)
In the previous slides, we saw how to use the CAPM to estimate the cost of capital of a firm’s equity
What about a firm’s debt — in other words, how to estimate the expected return required by a firm’s creditors?
In what follows, we’ll see some approaches for estimating the Debt Cost of Capital. Recall that the Cost of Capital of a given firm will then be a weighted average of the Equity and Debt costs
We’ll look at two different methods:
\[ \small r_d=\text{YTM} - \text{Prob. of Default}\times \text{Expected Loss given Default} \]
In order to see that, assume that the average loss rate for unsecured debt is 60%
During average times, the annual default rate for B-rated bonds is 5.5%.
In this case, the expected return to B-rated bondholders during average times is \(\small 0.055 \times 0.60 = 3.3\%\) below the bond’s quoted yield:
We can also use the CAPM to estimate debt cost through identifying the sensitivity of a given firm’s debt returns to the market returns
Approach #1: using the average estimates in Table and an expected loss rate of 60%, we have:
\[ \small r_d = 3\% - 0.5\% \times 0.6 = 2.7\% \]
Approach #2: alternatively, we can estimate the bond’s expected return using CAPM and an estimated beta of 0.10:
\[ \small r_d = 1.5\% + 0.10(8\%) = 2.3\% \]
\(\rightarrow\) Both estimates are rough approximations and they both suggest that the expected return of Autozone’s debt is below its yield-to-maturity of 3%
When we started studying the CAPM, the focus was to price the required returns of a company as a whole by means of the sensitivity of its returns with the market
What about investment opportunities within a firm (or, alternatively, that are not publicly traded)? Because a new project is not itself a publicly traded security, we cannot use historical risks of equity and debt to estimate beta and the cost of capital
Furthermore, the decision to invest in specific projects using the firm’s cost of capital might ignore the project’s risk:
Whenever we are evaluating a new project, the ultimate decision is assert whether or not to undertake a project:
How can we do this as the cost of capital that is required to make this decision is specific to a project, which does not have historical data available?
There are several ways in which we can use information to estimate such return
These methods range in the complexity in which we assume the project to have, as well as the source of funds that are used to fund the project
The simplest setting of a theoretical comparable firm is to find an all-equity financed firm (a firm with no debt) in a single line of business that is comparable to the project
Remember that:
Based on the information from this firm, use the comparable firm’s equity \(\beta\) and cost of capital as estimates to estimate the project’s cost of capital
\[ r_{\text{Project}} = 2.5\% + 1.3 \times 6.5\% = 10.95\% \]
What if the firm that we have used as a comparable peer is not 100% Equity? As a result, the situation is a bit more complicated if the comparable firm has debt
In that case, the cash flows generated by the firm’s assets are used to pay both debt and equity holders
Consequently, the returns of the firm’s equity (which are being measured using the \(\beta\) from its equity returns) alone are not representative of the underlying assets risk!
How can we compute the cost of capital of a given project whenever the comparable firm has debt? A method to solve this issue is to unlever the \(\beta\) of the comparable firm
To understand that, recall that a firm’s asset cost of capital or unlevered cost of capital is the expected return required by the firm’s investors to hold the firm’s underlying assets, and is a weighted average of the firm’s equity and debt costs of capital:
\[r_U = \frac{E}{E+D}\times r_E + \frac{D}{E+D} \times r_D\]
\[\beta_U = \frac{E}{E+D}\times \beta_E + \frac{D}{E+D} \times \beta_D\]
Why we should unlever the return on equity (or, alternatively, the equity \(\beta\))? Note that whenever we measure the cost of equity, we are measuring the expected returns based on the equity risk, which has some implicaitons if a given firm has debt:
But if you are evaluating a project based on a comparable firm that has debt, you want to consider only the risk of the underlying business, but not the risk due to financial leverage!
As a consequence, unlevering the \(\beta\) or the required return makes the comparison to be relative to the investments of a company, regardless of the financing structure!
\(\rightarrow\) See the Appendix for the calculations around how to lever (or unlever) \(\beta\) and expected returns
\(\rightarrow\) Solution: Company’s X equity cost of capital is:
\[ r_E = 2.5\% + 0.75 \times 6\% = 7\% \]
As a result, Company’s X unlevered cost of capital is (using the yield as debt cost):
\[r_U =\frac{77}{77+57} \times 7\% + \frac{57}{77+57} \times 4.1\% = 5.76\%\]
\[ \small \beta_u =\frac{77}{77+57} \times 0.75 + \frac{57}{77+57} \times 0 = 0.43 \]
\[ \small r_u = 2.5\% + 0,43 \times 6\% = 5.08\% \]
In the first case, we assumed that the expected return debt is equal to its promised yield of 3.2% (which overstates the return)
In the second, we assumed the debt has a beta of zero, which implies an expected return equal to the risk-free rate of 3% according (which underestimates the cost of debt
The truth is somewhere between the two results
Sometimes, firms maintain large cash balances in excess of their operating needs. Holding cash is a risk-free asset, and as so, reduces the average risk of the firm’s assets
Therefore, we should exclude cash holdings when computing the asset’s risk, as we’re interested in the risk of the firm’s underlying business operations, separate from its cash position
In that case, we can measure the leverage of the firm in terms of its net debt:
\[ \small \text{Net Debt} = Debt - \text{Excess Cash and Short-Term Investments} \]
Intuition: if a firm holds $1 in cash and has $1 in risk-free debt, then the interest earned on the cash will equal the interest paid on the debt
The cash flows from each source cancel each other, just as if the firm held no cash and no debt!
\[ \small \beta_U = \frac{E}{E+D}\times \beta_E + \frac{D}{E+D} \times \beta_D = \frac{18.8}{18.8-1.5}\times 0.93 + \frac{-1.5}{18.8-1.5} = 1.01 \]
Using a single comparable firm is often not a good idea, as there might be a lot of noise in the estimation of the results
However, it is possible to combine estimates of asset betas for multiple firms in the same industry to reduce our estimation error and improve the estimation accuracy:
\(\rightarrow\) See accompanying excel notebook with an exercise on Industry betas
\(\rightarrow\) See Damodaran (here) industry betas for the U.S.
We saw that we should evaluate a project’s cost of capital by comparing it with the unlevered assets of firms in the same line of business
However, even firm asset betas reflect the market risk of the average project in the firm. Individually, projects can differ in risk:
Thus far, presumed the project we are evaluating is all-equity financed:
What if the firm in which we wish to estimate the cost of capital is not 100% equity anymore?
For cases like this, we will turn our attention to the Weighted Average Cost of Capital (also known as WACC), the weighted average of the cost of capital from all the firm’s claimants:
\[ r_{\text{WACC}} = \frac{E}{D+E}\times r_E + \frac{D}{D+E} \times r_D \]
\[ r_{\text{WACC}} = \frac{E}{D+E}\times r_E + \frac{D}{D+E} \times r_D\times \underbrace{(1-\tau)}_{\text{Tax-shield}} \]
\[ r_{\text{WACC}} = \frac{E}{D+E}\times r_E + \frac{D}{D+E} \times r_D \]
\[ r_{\text{WACC}} = \frac{E}{D+E}\times r_e + \frac{D}{D+E} \times r_d\times (1-\tau) \]
\[ r_U = \frac{250}{250+100}\times 15\% + \frac{100}{250+100} \times 7\% = 12.71\% \]
\[r_{\text{WACC}} = \frac{250}{250+100}\times 15\% + \frac{100}{250+100} \times 7\% \times (1-34\%) = 12.03\%\]
Important
Practice using the following links:
\[ \small \beta_U = \frac{E}{E+D}\times \beta_E + \frac{D}{E+D} \times \beta_D \]
\[ \small \begin{align} &\beta_U = \frac{(E\times \beta_E +D\times \beta_D)}{E+D}\\ &\rightarrow E\times \beta_E =(E+D)\times\beta_U - D\times \beta_D\\ &\rightarrow\beta_E =\dfrac{(E+D)\times\beta_U - D\times \beta_D}{E}=\beta_U+\dfrac{D}{E}\times \beta_U-\dfrac{D}{E}\times \beta_D\\ &\rightarrow \beta_E= \beta_U+\dfrac{D}{E}\times(\beta_U-\beta_D) \end{align} \]
\[ \small r_U = \frac{E}{E+D}\times r_E + \frac{D}{E+D} \times r_D \]
\[ r_E= r_U+\dfrac{D}{E}\times(r_U-r_D) \]
\[ \small r_{\text{WACC}}=0.75 \times 12\% + 0.25\times 5.33\% \times (1- 25\%) = 10\% \]
\[ \small r_{\text{WACC}}=0.5 \times 12\% + 0.5\times 5.33\% \times (1- 25\%) = 8\% \]
\[ \small r_U = 0.75 \times 12\% + 0.25\times 5.33\% = 10.33\% \]
\[ \small r_E = 10.33\% + \dfrac{0.5}{0.5}\times(10.33\%-6.67\%)=14\% \]
\[ \small r_{\text{WACC}}=0.5 \times 14\% + 0.5\times 6.67\% \times (1- 25\%) = 9.5\% \]