
P1: ABC/ABC P2:c/d QC:e/f T1:g
c03 JWBT063-Rosenbaum March 25, 2009 9:25 Printer Name: Hamilton
Discounted Cash Flow Analysis
129
with 30-year maturities, Ibbotson Associates (“Ibbotson”)
21
uses an interpolated
yield for a 20-year bond as the basis for the risk-free rate.
22,23
Market Risk Premium (r
m
–r
f
or mrp) The market risk premium is the spread
of the expected market return
24
over the risk-free rate. Finance professionals, as
well as academics, often differ over which historical time period is most relevant for
observing the market risk premium. Some believe that more recent periods, such as
the last ten years or the post-World War II era are more appropriate, while others
prefer to examine the pre-Great Depression era to the present.
Ibbotson tracks data on the equity risk premium dating back to 1926. Depending
on which time period is referenced, the premium of the market return over the risk-
free rate (r
m
–r
f
) may vary substantially. For the 1926 to 2007 period, Ibbotson
calculates a market risk premium of 7.1%.
25
Many investment banks have a firm-wide policy governing market risk premium
in order to ensure consistency in valuation work across their various projects and
departments. The equity risk premium employed on Wall Street typically ranges from
approximately 4% to 8%. Consequently, it is important for the banker to consult
with senior colleagues for guidance on the appropriate market risk premium to use
in the CAPM formula.
Beta (ββ) Beta is a measure of the covariance between the rate of return on a
company’s stock and the overall market return (systematic risk), with the S&P 500
traditionally used as a proxy for the market. As the S&P 500 has a beta of 1.0, a
stock with a beta of 1.0 should have an expected return equal to that of the market.
A stock with a beta of less than 1.0 has lower systematic risk than the market, and a
stock with a beta greater than 1.0 has higher systematic risk. Mathematically, this is
captured in the CAPM, with a higher beta stock exhibiting a higher cost of equity;
and vice versa for lower beta stocks.
A public company’s historical beta may be sourced from financial informa-
tion resources such as Bloomberg,
26
FactSet, or Thomson Reuters. Recent historical
equity returns (i.e., over the previous two-to-five years), however, may not be
a reliable indicator of future returns. Therefore, many bankers prefer to use a
21
Morningstar acquired Ibbotson Associates in March 2006. Ibbotson Associates is a leading
authority on asset allocation, providing products and services to help investment professionals
obtain, manage, and retain assets. Morningstar’s annual Ibbotson
R
SBBI
R
(Stocks, Bonds,
Bills, and Inflation) Valuation Yearbook is a widely used reference for cost of capital input
estimations for U.S.-based businesses.
22
Bloomberg function: “ICUR20” <GO>.
23
While there are currently no 20-year Treasury bonds issued by the U.S. Treasury, as long as
there are bonds being traded with at least 20 years to maturity, there will be a proxy for the
yield on 20-year Treasury bonds.
24
The S&P 500
R
is typically used as the proxy for the return on the market.
25
Expected risk premium for equities is based on the difference of historical arithmetic mean
returns for the 1926 to 2007 period. Arithmetic annual returns are independent of one another.
Geometric annual returns are dependent on the prior year’s returns.
26
Bloomberg function: Ticker symbol <Equity> BETA <GO>.