Academics,
however, like to define investment "risk" differently, averring that
it is the relative volatility of a stock or portfolio of stocks - that is,
their volatility as compared to that of a large universe of stocks. Employing data bases 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.
For
owners of a business - and that's the way we think of shareholders - the
academics' definition of risk is far off the mark, so much so that it produces
absurdities. For example, under
beta-based theory, a stock that has dropped very sharply compared to the market
- as had Washington Post when we bought it in 1973 - becomes
"riskier" at the lower price than it was at the higher price. Would that description have then made any
sense to someone who was offered the entire company at a vastly-reduced price?
In
fact, the true investor welcomes volatility. Ben Graham explained why in Chapter 8 of The
Intelligent Investor. There he introduced
"Mr. Market," an obliging fellow who shows up every day to either buy
from you or sell to you, whichever you wish.
The more manic-depressive this chap is, the greater the opportunities
available to the investor. That's true
because a wildly fluctuating market means that irrationally low prices will
periodically be attached to solid businesses.
It is impossible to see how the availability of such prices can be
thought of as increasing the hazards for an investor who is totally free to either
ignore the market or exploit its folly.
In
assessing risk, a beta purist will disdain examining what a company produces,
what its competitors are doing, or how much borrowed money the business
employs. He may even prefer not to know
the company's name. What he treasures is
the price history of its stock. In
contrast, we'll happily forgo knowing the price history and instead will seek
whatever information will further our understanding of the company's
business. After we buy a stock,
consequently, we would not be disturbed if markets closed for a year or
two. We don't need a daily quote on our
100% position in See's or H. H. Brown to validate our well-being. Why, then, should we need a quote on our 7%
interest in Coke?
In
our opinion, the real risk that an investor must assess is whether his
aggregate after-tax receipts from an investment (including those he receives on
sale) will, over his prospective holding period, give him at least as much
purchasing power as he had to begin with, plus a modest rate of interest on
that initial stake. Though this risk
cannot be calculated with engineering precision, it can in some cases be judged
with a degree of accuracy that is useful.
The primary factors bearing upon this evaluation are:
1)
The certainty with which the long-term economic characteristics of the business
can be evaluated;
2)
The certainty with which management can be evaluated, both as to its ability to
realize the full potential of the business and to wisely employ its cash flows;
3)
The certainty with which management can be counted on to channel the rewards
from the business to the shareholders rather than to itself;
4)
The purchase price of the business;
5)
The levels of taxation and inflation that will be experienced and that will
determine the degree by which an investor's purchasing-power return is reduced
from his gross return.
These
factors will probably strike many analysts as unbearably fuzzy, since they
cannot be extracted from a data base of any kind. But the difficulty of
precisely quantifying these matters does not negate their importance nor is it
insuperable. Just as Justice Stewart
found it impossible to formulate a test for obscenity but nevertheless
asserted, "I know it when I see it," so also can investors - in an
inexact but useful way - "see" the risks inherent in certain
investments without reference to complex equations or price histories.
Is
it really so difficult to conclude that Coca-Cola and Gillette possess far less
business risk over the long term than, say, any computer company or
retailer? Worldwide, Coke sells about
44% of all soft drinks, and Gillette has more than a 60% share (in value) of
the blade market. Leaving aside chewing
gum, in which Wrigley is dominant, I know of no other significant businesses in
which the leading company has long enjoyed such global power.
Moreover,
both Coke and Gillette have actually increased their worldwide shares of market
in recent years. The might of their brand
names, the attributes of their products, and the strength of their distribution
systems give them an enormous competitive advantage, setting up a protective
moat around their economic castles. The
average company, in contrast, does battle daily without any such means of
protection. As Peter Lynch says, stocks
of companies selling commodity-like products should come with a warning label: "Competition
may prove hazardous to human wealth."
The
competitive strengths of a Coke or Gillette are obvious to even the casual
observer of business. Yet the beta of
their stocks is similar to that of a great many run-of-the-mill companies who
possess little or no competitive advantage.
Should we conclude from this similarity that the competitive strength of
Coke and Gillette gains them nothing when business risk is being measured? Or should we conclude that the risk in owning
a piece of a company - its stock - is somehow divorced from the long-term risk
inherent in its business operations? We
believe neither conclusion makes sense and that equating beta with investment
risk also makes no sense.
The
theoretician bred on beta has no mechanism for differentiating the risk
inherent in, say, a single-product toy company selling pet rocks or hula hoops
from that of another toy company whose sole product is Monopoly or Barbie. But it's quite possible for ordinary
investors to make such distinctions if they have a reasonable understanding of
consumer behavior and the factors that create long-term competitive strength or
weakness. Obviously, every investor will make mistakes. But by confining himself to a relatively few,
easy-to-understand cases, a reasonably intelligent, informed and diligent
person can judge investment risks with a useful degree of accuracy.
In
many industries, of course, Charlie and I can't determine whether we are
dealing with a "pet rock" or a "Barbie." We couldn't solve this problem, moreover,
even if we were to spend years intensely studying those industries. Sometimes our own intellectual shortcomings
would stand in the way of understanding, and in other cases the nature of the
industry would be the roadblock. For
example, a business that must deal with fast-moving technology is not going to
lend itself to reliable evaluations of its long-term economics. Did we foresee thirty years ago what would
transpire in the television-manufacturing or computer industries? Of course not. (Nor did most of the investors and corporate
managers who enthusiastically entered those industries.) Why, then, should
Charlie and I now think we can predict the future of other rapidly-evolving
businesses? We'll stick instead with the
easy cases. Why search for a needle
buried in a haystack when one is sitting in plain sight?
Of
course, some investment strategies - for instance, our efforts in arbitrage
over the years - require wide diversification. If significant risk exists in a
single transaction, overall risk should be reduced by making that purchase one
of many mutually-independent commitments.
Thus, you may consciously purchase a risky investment - one that indeed
has a significant possibility of causing loss or injury - if you believe that
your gain, weighted for probabilities, considerably exceeds your loss,
comparably weighted, and if you can commit to a number of similar, but
unrelated opportunities. Most venture
capitalists employ this strategy. Should
you choose to pursue this course, you should adopt the outlook of the casino
that owns a roulette wheel, which will want to see lots of action because it is
favored by probabilities, but will refuse to accept a single, huge bet.
Another
situation requiring wide diversification occurs when an investor who does not
understand the economics of specific businesses nevertheless believes it in his
interest to be a long-term owner of American industry. That investor should both own a large number
of equities and space out his purchases.
By periodically investing in an index fund, for example, the know-nothing
investor can actually out-perform most investment professionals. Paradoxically, when "dumb" money
acknowledges its limitations, it ceases to be dumb.
On
the other hand, if you are a know-something investor, able to understand
business economics and to find five to ten sensibly-priced companies that
possess important long-term competitive advantages, conventional
diversification makes no sense for you. It
is apt simply to hurt your results and increase your risk. I cannot understand why an investor of that
sort elects to put money into a business that is his 20th favorite rather than
simply adding that money to his top choices - the businesses he understands
best and that present the least risk, along with the greatest profit
potential. In the words of the prophet
Mae West: "Too much of a good thing
can be wonderful."
Warren
E. Buffett
March
1, 1994
No hay comentarios:
Publicar un comentario