5. Risk and discount rates. Conventional academic and practitioner thinking held that the more risk one took, the more one should get paid. Thus, discount rates used in determining intrinsic values should be determined by the risk of the cash flows being valued. The conventional model for estimating discount rates was the capital asset pricing model (CAPM), which added a risk premium to the long-term risk-free rate of return, such as the U.S. Treasury bond yield.
Buffett departed from conventional thinking by using the rate of return on the long-term (for example, 30 year) U.S. Treasury bond to discount cash flows.13 Defending this practice, Buffett argued that he avoided risk, and therefore should use a “risk-free” discount rate. His firm used almost no debt financing. He focused on companies with predictable and stable earnings. He or his vice chair, Charlie Munger, sat on the boards of directors, where they obtained a candid, inside view of the company and could intervene in managements’ decisions if necessary. Buffett once said, “I put a heavy weight on certainty. If you do that, the whole idea of a risk factor doesn’t make sense to me. Risk comes from not knowing what you’re doing.”14 He also wrote:
We define risk, using dictionary terms, as “the possibility of loss or injury.”
Academics, however, like to define “risk” differently, averring that it is the
relative volatility of a stock or a portfolio of stocks—that is, the volatility as
compared to that of a large universe of stocks. Employing databases and
statistical skills, these academics compute with precision the “beta” of a stock—
its relative volatility in the past—and then build arcane investment and capital
allocation theories around this calculation. In their hunger for a single statistic to
measure risk, however, they forget a fundamental principle: it is better to be
approximately right than precisely wrong.15