Estimating the Cost-of-Capital
Another important application of the RIM has been in estimating a cost-of-capital.
More than three decades after the development of the Capital Asset Pricing Model
(CAPM), the field of finance continues to struggle with the practical and elemental
problem of estimating a firm's cost-of-equity-capital. This problem is perhaps the single
most pressing research issue in corporate finance.
The traditional approach to compute a cost-of-capital is fraught with estimation
problems. These problems are so severe that the resulting cost-of-capital estimates have
invariably been hopelessly imprecise.'^ Several recent studies in accounting have suggested
an alternative approach. Specifically, they have used the RIM and current market
prices to compute an implied cost-of-capital, i.e., the cost-of-capital that the market
implicitly uses to discount the expected future cash flows of the company. Although this
approach also has its problems, the initial results appear promising.
For example, Botosan (1997) uses this implied rate in evaluating the effect of disclosure
policies on the cost-of-capital. Her results suggest that firms with limited analyst
coverage that provide higher levels of disclosure appear to enjoy lower costs-of-capital.
Claus and Thomas (1998) use the RIM to estimate an aggregate implied market risk
premium. They show that the market risk premium estimated using the RIM is much
lower than the risk premium estimated using historical realized returns. They conclude
that perhaps the current stock market is not as over-priced as it first appears.