The Commanding General is well aware the forecasts are no good. However, he needs them for planning purposes.”
– Kenneth Arrow, Nobel Laureate Economist…recalling the response he
and colleagues received during the Second World War when they
demonstrated that the military’s long-term weather forecasts were
useless. (via
Future Babble)
Virtually every day there are pundits and gurus on the airwaves,
internet, and print making predictions. At the beginning of 2011 a few
of these gurus made some pronouncements as to the future returns of the
US stock market. Laszlo Biryini contended that the S&P 500
(currently trading at 1300 as of this writing – sorry, wrote this about a
week ago) would rise to 2854 by 2013, or a 120% gain from current
levels. Robert Prechter, on the other hand, said he thought the Dow
would decline 90% by 2017, which would imply that the S&P 500 trades
down to around 130.
So there you have it, opposing gurus who believe that stocks will
either rise or decline by 30% annualized over the next number of years.
(To complicate the matter even further, you have Shiller estimating the
S&P 500 to gain about 10% total by 2020 which splits the two gurus
in half.)
Interestingly enough, if you combine the current S&P 500 level
(1300, PE of 23) with the lowest (5) and highest historical values (45)
for the Shiller cyclically adjusted price earnings ratio (CAPE) you get
to values similar to the forecasts at both ends (300 and 2600). I think
the most interesting but unlikely forecast is all three being correct
over various timeframes!
The only difference between the S&P500 at 300 (an 80% decline)
and the S&P500 at 2600 (a near double) is opinion, namely, what you
think those underlying stocks are worth. Now, we could certainly go on
and on making well-thought out arguments as to why either value is
justified (low/high interest rates, profit margins, productivity, mean
reversion, discounted cash flows, etc.), but at the end of the day it is
simple human beliefs on the value of stocks that drive their short term
price levels. As the late, great Kurt Vonnegut opined in his book
Galapagos,
circa 1985:
“The thing was, though: When James Wait
got there, a worldwide financial crisis, a sudden
revision of human
opinions as to the value of money and stocks and bonds and mortgages and
so on, bits of paper, had ruined the tourist business not only in
Ecuador, but practically everywhere…Ecuador, after all, like the
Galapagos Islands, was mostly lava and ash, and so could not begin to
feed its nine million people. It was bank
http://mebfaber.com/2011/08/09/all-that-had-changed-was-people%E2%80%99s-opinion-of-the-place/rupt, and so could no longer
buy food from countries with plenty of topsoil, so the seaport of
Guayaquil was idle, and the people were beginning to starve to
death…Neighboring Peru and Columbia were bankrupt, too…Mexico and Chile
and Brazil and Argentina were likewise bankrupt – and Indonesia and the
Philippines and Pakistan and India and Thailand and and Italy and
Ireland and Belgium and Turkey. Whole nations were suddenly in the same
situation as the
San Mateo, unable to buy with their paper
money and coins, or their written promises to pay later, even the barest
essentials. ..They were suddenly saying to people with nothing but
paper representations of wealth, “Wake up, you idiots! Whatever made you
think paper was so valuable?”
The financial crisis was simply the
latest in a series of murderous twentieth century catastrophes which had
originated entirely in human brains. From the violence people were
doing to themselves and each other, and to all other living things, for
that matter, a visitor from another planet might have assumed that the
environment had gone haywire, and that people were in such a frenzy
because Nature was about to kill them all.
But the planet a million years ago was as
moist and nourishing as it is today – and unique, in that respect, in
the entire Milky Way. All that had changed was people’s opinion of the place.”
How does an investment manager reconcile all of the various prognostications he hears on a daily basis?
Simple – ignore them.
Now I am not recommending to completely ignore the basis behind the
arguments, as many new approaches and research projects have been
originated by ideas presented in print and on TV. But in general, one
should ignore the
forecasts of so called experts as they are
likely to be about as accurate as a monkey throwing darts against a wall
or a coin flip. There is enormous amount of research to back up the
inability of experts to make solid predictions.
One such researcher on expert predictions is Philip Tetlock, a
professor of management at the Wharton School at UPenn . He started
tracking experts and their forecasts and predictions a quarter century
ago, and he has compiled over 300 professionals and academics that have
made over 80,000 forecasts. (Here is
Tetlock’s home page as well as a
sample book chapter. Daniel Drezner has two excellent posts on the book,
here and
here, and a
review from The New Yorker.)
He examined both the outcomes of their predictions as well as their
processes – i.e. how they reacted to being wrong and how they dealt with
contrary evidence. In general they offered no benefit over a random
prediction, and ironically enough, the more famous the expert, the less
accurate the predictions were. The experts with the least confidence
made the best predictions.
Tetlock states:
“Isaiah Berlin borrowed from a Greek
poet, “The fox knows many things, but the hedgehog knows one big thing”?
The better forecasters were like Berlin’s foxes: self-critical,
eclectic thinkers who were willing to update their beliefs when faced
with contrary evidence, were doubtful of grand schemes and were rather
modest about their predictive ability. The less successful forecasters
were like hedgehogs: They tended to have one big, beautiful idea that
they loved to stretch, sometimes to the breaking point. They tended to
be articulate and very persuasive as to why their idea explained
everything. The media often love hedgehogs. “
BECOMING A BETTER INVESTOR
The characteristics enabling one to appear on TV and become a famous
pundit are not the same as the characteristics of being a successful
trader or money manager. Here is a passage from Future Babble on how to
be a successful pundit, as illustrated by the charismatic
overpopulation doomsdayer Paul Ehrlich:
“Be articulate, enthusiastic, and
authoritative. Be likable. See things through a single analytical lens
and craft an explanatory story that is simple, clear, conclusive, and
compelling. Do not doubt yourself. Do not acknowledge mistakes. And
never, ever say, “I don’t know.”
People unsure about the future want to hear from confident experts
who tell a good story, and Paul Ehrlich was among the very best. The
fact that his predictions were mostly wrong didn’t change that in the
slightest.”
Now notice the difference in thinking with one of the greatest hedge
fund managers ever, George Soros, “I think that my conceptual framework,
which basically emphasizes the importance of misconceptions, makes me
extremely critical of my own decisions.” I know that I am bound to be
wrong, and therefore more likely to correct my own mistakes.”
Most of the greatest traders and money managers I know think in terms
of all sorts of possibilities and probabilities of various scenarios.
Likewise, this follows in line with the old Maynard Keynes
expression, “When the facts change I change my mind. What do you do
sir?”
Indeed, the title of one of my favorite investment books is “Being
Right or Making Money” by Ned Davis. The title alone summarizes almost
everything an investor needs to know about investing – do you care more
about being correct, or do you care more about increasing your wealth?