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The Efficient Market Hypothesis, according to Shiller, is one of the most
remarkable errors in the history of economic thought. EMH should be consigned
to the dustbin of history. We need to stop teaching it, and brainwashing the
innocent. Rob Arnott tells a lovely story of a speech he was giving to some
200 finance professors. He asked how many of them taught EMH - pretty much
everyone's hand was up. Then he asked how many of them believed it. Only two
hands stayed up!
And we wonder why funds and banks, full of the best and brightest, have made
such a mess of things. Part of the reason is that we have taught economic nonsense
to two generations of students. They have come to rely upon models based on
assumptions that are absurd on their face. And then they are shocked when the
markets deliver them a "hundred-year flood" every 4 years. The models say this
should not happen. But do they abandon their models? No, they use them to convince
regulators that things should not be changed all that much. And who can argue
with a model that was the basis for a Nobel Prize?
I am again out of town this week, but I have been saving a speech done by
my friend James Montier of Société Générale in
London on the problems with the Efficient Market Hypothesis (EFM). While parts
of it are wonkish, there are also parts that are quite funny (at least to an
economist).
Ideas have consequences, and bad ideas usually have bad consequences. The
current maelstrom from which we are emerging (finally, if in fits and starts)
has many culprits. A lot of bad ideas and poor management that came together
to create the perfect storm. Today, we look at some of the ideas that are part
of the problem but are too often glossed over because they are "academic" and
not of the real world. However, gentle reader, academic ideas that are taught
and accepted as gospel by 99% of the professors have real-world consequences.
Where does your money manager stand on these topics? It does make a difference.
And now, let's jump into James's speech.
Six impossible things before breakfast, or how EMH has damaged
our industry
What follows is the text of a speech to be delivered at the CFA UK conference
on "What ever happened to EMH". Dedicated to Peter Bernstein - Peter will be
fondly remembered and sadly missed by all who work in investment. Although
he and I often ended up on opposite sides of the debates, he was true gentleman
and always a pleasure to discuss ideas with. I am sure Peter would have disagreed
with some, much and perhaps all of my speech today, but I'm equally sure he
would have enjoyed the discussion.
The Dead Parrot of Finance
Given that this is the UK division of the CFA I am sure that The Monty Python
Dead Parrot Sketch will be familiar to all of you. The EMH is the financial
equivalent of the Dead Parrot. I feel like the John Cleese character (an exceedingly
annoyed customer who recently purchased a parrot) returning to the petshop
to berate the owner:
"He's passed away, This parrot is no more, He has ceased to be! He's expired
and gone to meet his maker. He's a stiff! Bereft of Life, he rests in peace!
If you hadn't nailed him to the perch he'd be pushing up daisies! His metabolic
processes are now history! He's off the twig! He kicked the bucket. He's
shuffled off his mortal coil, run down the curtain and joined the bleedin'
choir invisible! This is an ex-parrot!!!"
The shopkeeper (picture Gene Fama if you will) keeps insisting the parrot
is simply resting. Incidentally, the Dead Parrot Sketch takes on even more
meaning when you recall Stephen Ross's words that "All it takes to turn a parrot
into a learned financial economist is just one word - arbitrage".

The EMH supporters have strong similarities with the Jesuit astronomers of
the 17th Century who desperately wanted to maintain the assumption that the
Sun revolved around the Earth. The reason for this desire to protect the maintained
hypothesis was simple. If the Sun didn't revolve around the Earth, then the
Bible's tale of Joshua asking God to make the Sun stand still in the sky was
a lie. A bible that lies even once can't be the inerrant foundation for faith!
The efficient market hypothesis (EMH) has done massive amounts of damage to
our industry. But before I explore some errors embedded within the approach
and the havoc that they have wreaked, I would like to say a few words on why
the EMH exists at all.
Academic theories are notoriously subject to path dependence (or hysteresis,
if you prefer). Once a theory has been adopted it takes an enormous amount
of effort to dislocate it. As Max Planck said "Science advances one funeral
at a time".
The EMH has been around in one form or another since the Middle Ages (the
earliest debate I can find is between St. Thomas Aquinas and other monks on
the 'just' price to charge for corn, with St. Thomas arguing that the 'just'
price was the market price). Just imagine we had all grown up in a parallel
universe. David Hirschleifer did exactly that: welcome to his world of the
Deficient Markets Hypothesis.
"A school of sociologists at the University of Chicago proposing the Deficient
Markets Hypothesis - that prices inaccurately reflect all information. A
brilliant Stanford psychologist, call him Bill Blunte, invents the Deranged
Anticipation and Perception Model (DAPM), in which proxies for market misevaluation
are used to predict security returns. Imagine the euphoria when researchers
discovered that these mispricing proxies (such as book/market, earnings/price
and past returns), and that mood indicators such as amount of sunlight, turned
out to be strong predictors of future returns. At this point, it would seem
that the Deficient Markets Hypothesis was the best-confirmed theory in social
science.
To be sure, dissatisfied practitioners would have complained that it is
harder to actually make money than the ivory tower theorists claim. One can
even imagine some academic heretics documenting rapid short-term stock market
responses to news arrival in event studies, and arguing that security return
predictability results from rational premia for bearing risk. Would the old
guard surrender easily? Not when they could appeal to intertemporal versions
of the DAPM, in which mispricing is only corrected slowly. In such a setting,
short window event studies cannot uncover the market's inefficient response
to new information. More generally, given the strong theoretical underpinnings
of market inefficiency, the rebels would have an uphill fight."
In finance we seem to have a chronic love affair with elegant theories. Our
faculties for critical thinking seem to have been overcome by the seductive
power of mathematical beauty. A long, long time ago, when I was a young and
impressionable lad starting out in my study of economics I too was enthralled
by the bewitching beauty and power of the EMH/rational expectations approach
(akin to the Dark Side in Star Wars). However, in practice we should always
remember that there are no points for elegance!
My own disillusionment with EMH and the ultra rational Homo Economius that
it rests upon came in my third year of university. I sat on the oversight committee
for my degree course as a student representative. Now at the university I attended
it was possible to elect to graduate with a specialism in Business Economics,
if you took a prescribed set of courses. The courses necessary to attain this
degree were spread over two years. It wasn't possible to do all the courses
in one year, so students needed to stagger their electives. Yet at the beginning
of the third year I was horrified to find students coming to me to complain
that they hadn't realised this! These young economists had failed to solve
the simplest two-period optimisation problem I can imagine! What hope for the
rest of the world. Perhaps I am living evidence that finance is like smoking.
Ex-smokers always seem to provide the most ardent opposition to anyone lighting
up. Perhaps the same thing is true in finance!
The Queen of Hearts and impossible beliefs
I'm pretty sure that the Queen of Hearts would have made an excellent EMH
economist.
"Alice laughed: "There's no use trying," she said; "one can't believe impossible
things."
"I daresay you haven't had much practice," said the Queen. "When I was younger,
I always did it for half an hour a day. Why, sometimes I've believed as many
as six impossible things before breakfast.""
Lewis Carroll, Alice in Wonderland.
Earlier I alluded to a startling lack of critical thinking in finance. This
lack of 'logic' isn't specific to finance, in general we, as a species, suffer
belief bias. This a tendency to evaluate the validity of an argument on the
basis of whether or not one agrees with the conclusion, rather than on whether
or not it follows logically from the premise.
Consider these four syllogisms:
- No police dogs are vicious.
Some highly trained dogs are vicious.
Therefore some highly trained dogs are not police dogs.
- No nutritional things are inexpensive.
Some vitamin pills are inexpensive.
Therefore, some vitamin pills are not nutritional.
- No addictive things are inexpensive.
Some cigarettes are inexpensive.
Therefore, some addictive things are not cigarettes.
- No millionaires are hard workers.
Some rich people are hard workers.
Therefore, some millionaires are not rich people.
These four syllogisms provide us with a mixture of validity and believability.
The table below separates out the problems along these two dimensions. This
enables us to assess which criteria people use in reaching their decisions.

As the chart reveals, it is the believability not the validity of the concept
that seems to drive behaviour. When validity and believability coincide, then
90% of subjects reach the correct conclusion. However, when the puzzle is invalid
but believable, some 66% still accepted the conclusion as true. When the puzzle
is valid but unbelievable only around 60% of subjects accepted the conclusion
as true. Thus we have a tendency to judge things by their believability rather
than their validity - clear evidence that logic goes out of the window when
beliefs are strong.

All this talk about beliefs makes EMH sound like a religion. Indeed, it has
some overlap with religion in that belief appears to be based on faith rather
than proof. Debating the subject can also give rise to the equivalent of religious
fanaticism. In his book 'The New Finance: The Case Against Efficient Markets',
Robert Haugen (long regarded as a heretic by many in finance) recalls a conference
he was speaking at where he listed various inefficiencies. Gene Fama was in
the audience and at one point yelled "You're a criminal....God knows markets
are efficient".
Slaves of some defunct economist
To be honest I wouldn't really care if EMH was just some academic artefact.
The real damage unleashed by the EMH stems from the fact that as Keynes long
ago noted "practical men... are usually the slaves of some defunct economist".
So let's turn to the investment legacy that the EMH has burdened us with:
first off is the Capital Asset Pricing Model (CAPM). I've criticised the CAPM
elsewhere (see Chapter 35 of Behavioural Investing), so I won't dwell on the
flaws here, but suffice it to say that my view remains that CAPM is CRAP (Completely
Redundant Asset Pricing).
The aspects of CAPM that we do need to address here briefly are the ones that
hinder the investment process. One of the most pronounced of which is the obsession
with performance measurement. The separation of alpha and beta is at best an
irrelevance and at worst a serious distraction from the true nature of investment.
Sir John Templeton said it best when he observed that "the aim of investment
is maximum real returns after tax". Yet instead of focusing on this target,
we have spawned one industry that does nothing other than pigeonhole investors
into categories.
As the late, great Bob Kirby opined "Performance measurement is one of those
basically good ideas that somehow got totally out of control. In many cases,
the intense application of performance measurement techniques has actually
served to impede the purpose it is supposed to serve."
The obsession with benchmarking also gives rise to one of the biggest sources
of bias in our industry - career risk. For a benchmarked investor, risk is
measured as tracking error. This gives rise to Homo Ovinus - a species who
are concerned purely with where they stand relative to the rest of the crowd.
(For those who aren't up in time to listen to Farming Today, Ovine is the proper
name for sheep). This species is the living embodiment of Keynes' edict that "it
is better for reputation to fail conventionally than to succeed unconventionally".
More on this poor creature a little later.

Whilst on the subject of benchmarking, we can't leave without observing that
EMH and CAPM also give rise to market indexing. Only in an efficient market
is a market cap-weighted index the 'best' index. If markets aren't efficient
then cap weighting leads us to overweight the most expensive stocks and underweight
the cheapest stocks!
Before we leave risk behind, we should also note the way in which fans of
EMH protect themselves against evidence that anomalies such as value and momentum
exist. In a wonderfully tautological move, they argue that only risk factors
can generate returns in an efficient market, so these factors must clearly
be risk factors!
Those of us working in the behavioural camp argue that behavioural and institutional
biases are the root causes of the outperformance of the various anomalies.
I have even written papers showing that value isn't riskier than growth on
any definition that the EMH fans might choose to use (see Mind
Matters, 21 April 2008 for details).
For instance, if we take the simplest definition of risk used by the EMH fans
(the standard deviation of returns), then the chart below shows an immediate
issue for EMH. The return on value stocks is higher than the return on growth
stocks, but the so-called 'risk' of value stocks is lower than the risk of
growth stocks - in complete contradiction to the EMH viewpoint.

This overt focus on risk has again given rise to what is in my view yet another
largely redundant industry - risk management. The tools and techniques are
deeply flawed. The use of measures such as VaR gives rise to the illusion of
safety. All too often they use trailing inputs calculated over short periods
of time, and forget that their model inputs are effectively endogenous. The
'risk' inputs such as correlation and volatility are a function of a market
which functions more like poker than roulette (i.e. the behaviour of the other
players matters).
Risk shouldn't be defined as standard deviation (or volatility). I have never
met a long-only investor who gives a damn about upside volatility. Risk is
an altogether more complex topic - I have argued that a trinity of risk sums
up the aspects that investors should be looking at. Valuation risk, business
or earnings risk, and balance sheet risk.
Of course, under CAPM the proper measure of risk is beta. However, as Ben
Graham pointed out beta measures price variability, not risk. Beta is probably
most often used by analysts in their calculations of the cost of capital, and
indeed by CFOs in similar calculations. However, even here beta is unhelpful.
Far from the theoretical upward sloping relationship between risk and return,
the evidence (including that collected by Fama and French) shows no relationship,
and even arguably an inverse one from the model prediction.
This, of course, ignores the difficulties and vagaries of actually calculating
beta. Do you use, daily, weekly or monthly data, over what time period? The
answers to these questions are non-trivial in their impact upon the analysts
calculations. In a very recent paper, Fernandez and Bermejo showed that the
best approach might simply to assume that beta equals 1.0 for all stocks. (Another
reminder that there are no points for elegance in this world!)
The EMH has also given us the Modigliani and Miller propositions on dividend
irrelevance, and capital structure irrelevance. These concepts have both been
used by unscrupulous practitioners to further their own causes. For instance,
those in favour of repurchases over dividends, or even those in favour of retained
earnings over distributed earnings, have effectively relied upon the M&M
propositions to argue that shareholders should be indifferent to the way in
which they receive their return (ignoring the inconvenient evidence that firms
tend to piss away their retained earnings, and that repurchases are far more
transitory in nature than dividends).
Similarly, the M&M capital structure irrelevance proposition has encouraged
corporate financiers and corporates themselves to gear up on debt. After all,
according to this theory investors shouldn't care whether 'investment' is financed
by retained earnings, equity issuance or debt issuance.
The EMH also gave rise to another fallacious distraction of our world - shareholder
value. Ironically this started out as a movement to stop the focus on short-term
earnings. Under EMH, the price of a company is, of course, just the net present
value of all future cash flows. So focusing on maximizing the share price was
exactly the same thing as maximizing future profitability. Unfortunately in
a myopic world this all breaks down, and we end up with a quest to maximize
short-term earnings!
But perhaps the most insidious aspect of the EMH is the way in which it has
influenced the behaviour of active managers in their pursuit of adding value.
This might sound odd, but bear with me while I try to explain what might upon
cursory inspection sound like an oxymoron.
All but the most diehard of EMH fans admit that there is a role for active
management. After all, who else would keep the market efficient - a point first
made by Grossman and Stigliz in their classic paper, 'The impossibility of
the informational efficient market'. The extreme diehards probably wouldn't
even tolerate this, but their arguments don't withstand the reductio ad
absurdum that if the market were efficient, prices would of course be correct,
and thus volumes should be equal to zero.
The EMH is pretty clear that active managers can add value via one of two
routes. First there is inside information - which we will ignore today because
it is generally illegal in most markets. Second, they could outperform if they
could see the future more accurately than everyone else.
The EMH also teaches us that opportunities will be fleeting as someone will
surely try to arbitrage them away. This, of course, is akin to the age old
joke about the economist and his friend walking along the street. The friend
points out a $100 bill lying on the pavement. The economist says, "It isn't
really there because if it were someone would have already picked it up".
Sadly these simple edicts are no joking matter as they are probably the most
damaging aspects of the EMH legacy. Thus the EMH urges investors to try and
forecast the future. In my opinion this is one of the biggest wastes of time,
yet one that is nearly universal in our industry. Pretty much 80-90% of the
investment processes that I come across revolve around forecasting. Yet there
isn't a scrap of evidence to suggest that we can actually see the future at
all.



The EMH's insistence on the fleeting nature of opportunities combined with
the career risk that bedevils Homo Ovinus has led to an overt focus on the
short-term. This is typified by the chart below which shows the average holding
period for a stock on the New York Stock Exchange. It is now just six months!

The undue focus upon benchmark and relative performance also leads Homo Ovinus
to engage in Keynes' beauty contest. As Keynes wrote:
"Professional investment may be likened to those newspaper competitions
in which the competitors have to pick out the six prettiest faces from a
hundred photographs, the price being awarded to the competitor whose choice
most nearly corresponds to the average preference of the competitors as a
whole; so that each competitor has to pick, not those faces which he himself
finds prettiest, but those which he thinks likeliest to catch the fancy of
the other competitors, all of whom are looking at the problem from the same
point of view. It is not a case of choosing those which, to the best of one's
judgment, are really prettiest, nor even those which average opinion genuinely
thinks the prettiest. We have reached the third degree where we devote our
intelligences to anticipating what average opinion expects the average opinion
to be. And there are some, I believe, who practice the fourth, fifth and
higher degrees"
This game can be easily replicated by asking people to pick a number between
0 and 100, and telling them the winner will be the person who picks the number
closest to two-thirds the average number picked. The chart below shows the
results from the largest incidence of the game that I have played - in fact
the third largest game ever played, and the only one played purely among professional
investors.

The highest possible correct answer is 67. To go for 67 you have to believe
that every other muppet in the known universe has just gone for 100. The fact
we got a whole raft of responses above 67 is more than slightly alarming.
You can see spikes which represent various levels of thinking. The spike at
fifty reflects what we (somewhat rudely) call level zero thinkers. They are
the investment equivalent of Homer Simpson, 0, 100, duh 50! Not a vast amount
of cognitive effort expended here!
There is a spike at 33 - of those who expect everyone else in the world to
be Homer. There's a spike at 22, again those who obviously think everyone else
is at 33. As you can see there is also a spike at zero. Here we find all the
economists, game theorists and mathematicians of the world. They are the only
people trained to solve these problems backwards. And indeed the only stable
Nash equilibrium is zero (two-thirds of zero is still zero). However, it is
only the 'correct' answer when everyone chooses zero.
The final noticeable spike is at one. These are economists who have (mistakenly...)
been invited to one dinner party (economists only ever get invited to one dinner
party). They have gone out into the world and realised the rest of the world
doesn't think like them. So they try to estimate the scale of irrationality.
However, they end up suffering the curse of knowledge (once you know the true
answer, you tend to anchor to it). In this game, which is fairly typical, the
average number picked was 26, giving a two-thirds average of 17. Just three
people out of more than 1000 picked the number 17.
I play this game to try to illustrate just how hard it is to be just one step
ahead of everyone else - to get in before everyone else, and get out before
everyone else. Yet despite this fact, it seems to be that this is exactly what
a large number of investors spend their time doing.
Prima facie case against EMH -- Forever blowing bubbles
Let me now turn to the prima facie case against the EMH. Oddly enough it is
one that doesn't attract much attention in academia. As Larry Summers pointed
out in his wonderful parody of financial economics "Traditional finance is
more concerned with checking that two 8oz bottles of ketchup is close to the
price of one 16oz bottle, than in understanding the price of the 16oz bottle".
The first stock exchange was founded in 1602. The first equity bubble occurred
just 118 years later - the South Sea bubble. Since then we have encountered
bubbles with an alarming regularity. My friends at GMO define a bubble as a
(real) price movement that is at least two standard deviations from trend.
Now a two standard deviation event should occur roughly every 44 years. Yet
since 1925, GMO have found a staggering 30 plus bubbles. That is equivalent
to slightly more than one every three years!
In my own work I've examined the patterns that bubbles tend to follow. By
looking at some of the major bubbles in history (including the South Sea Bubble,
the railroad bubble of the 1840s, the Japanese bubble of the late 1980s, and
the NASDAQ bubble¹), I have been able to extract the following underlying
pattern. Bubbles inflate over the course of around three years, with an almost
parabolic explosion in prices towards the peak of the bubble. Then without
exception they deflate. This bursting is generally slightly more rapidly than
the inflation, taking around two years.

Whilst the details and technicalities of each episode are different, the underlying
dynamics follow a very similar pattern. As Mark Twain put it "History doesn't
repeat but it does rhyme". Indeed, the first well documented analysis of the
underlying patterns of bubbles that I can find is a paper by J.S. Mills in
1867. He lays out a framework that is very close to the Minsky/Kindleberger
model that I have used for years to understand the inflation and deflation
of bubbles. This makes it hard to understand why so many amongst the learned
classes seem to believe that you can't identify a bubble before it bursts.
To my mind the clear existence and ex ante diagnosis of bubbles represent by
far and away the most compelling evidence of the gross inefficiency of markets.
The EMH 'Nuclear Bomb'
Now as a behaviouralist I am constantly telling people to beware of confirmatory
bias - the habit of looking for information that agrees you. So in an effort
to avert the accusation that I am guilty of failing to allow for my own biases
(something I've done before), I will now turn to the evidence that the EMH
fans argue is the strongest defence of their belief - the simple fact that
active management doesn't outperform. Mark Rubinstein describes this as the
nuclear bomb of the EMH, and says we behaviouralists have nothing in our arsenal
to match it, our evidence of inefficiencies and irrationalities amounts to
puny rifles.
However, I will argue that this viewpoint is flawed both theoretically and
empirically. The logical error is a simple one. It is to confuse the absence
of evidence with evidence of the absence. That is to say, if the EMH leads
active investors to focus on the wrong sources of performance (i.e. forecasting),
then it isn't any wonder that active management won't be able to outperform.
Empirically, the 'nuclear bomb' is also suspect. Today I want to present two
pieces of evidence that highlight the suspect nature of the EMH claim. The
first is work by Jonathan Lewellen of Dartmouth College.
In a recent paper, Lewellen looked at the aggregate holdings of US institutional
investors over the period 1980-2007. He finds that essentially they hold the
market portfolio. To some extent this isn't a surprise, as the share of institutional
ownership has risen steadily over time from around 30% in 1980 to almost 70%
at the end of 2007. This confirms the zero sum game aspect of active management
(or negative sum, after costs) and also the validity of Keynes' observation
that it [the market] is professional investors trying to outsmart each other.

However, Lewellen also shows that, in aggregate, institutions don't try to
outperform! He sorts stocks into quintiles based on a variety of characteristics
and then compares the fraction of the institutional portfolio invested in each
(relative to institutions' investment in all five quintiles) with the quintile's
weight in the market portfolio (the quintile's market cap relative to the market
cap of all five quintiles) - i.e. he measures the weight institutional investors
place on a characteristic relative to the weight the market places on each
trait.
The chart below shows the results for a sample of the characteristics that
Lewellen used. With the exception of size, the aggregate institutional portfolio
barely deviates from the market weights. So institutions aren't even really
trying to tilt their portfolios towards the factors we know generate outperformance
over the long term.

Lewellen concludes:
"Quite simply, institutions overall seem to do little more than hold the
market portfolio, at least from the standpoint of their pre-cost and pre-fee
returns. Their aggregate portfolio almost perfectly mimics the value-weighted
index, with a market beta of 1.01 and an economically small, precisely estimated
CAPM alpha of 0.08% quarterly. Institutions overall take essentially no bet
on any of the most important stock characteristics known to predict returns,
like book-to market, momentum, or accruals. The implication is that to the
extent that institutions deviate from the market portfolio, they seem to
bet primarily on idiosyncratic returns - bets that aren't particularly successful.
Another implication is that institutions, in aggregate, don't exploit anomalies
in the way they should if they rationally tried to maximize the (pre-cost)
mean variance trade-off of their portfolios, either relative or absolute."
Put into our terms, institutions are more worried about career risk (losing
your job) or business risk (losing funds under management) than they are about
doing the right thing!
The second piece of evidence I'd like to bring to your addition is a paper
by Randy Cohen, Christopher Polk and Bernhard Silli. They examined the 'best
ideas' of US fund managers over the period 1991-2005. 'Best ideas' are measured
as the biggest difference between the managers' holdings and the weights in
the index.
The performance of these best ideas is impressive. Focusing on the top 25%
of best ideas across the universe of active managers, Cohen et al find that
the average return is over 19% p.a. against a market return of 12% p.a. That
is to say, the stocks in which the managers display most confidence did outperform
the market by a significant degree.
The corollary to this is that the other stocks they hold are dragging down
their performance. Hence it appears that the focus on relative performance
-and the fear of underperformance against an arbitrary benchmark - is a key
source of underperformance.
At an anecdotal level I have never quite recovered from discovering that a
value manager at a large fund was made to operate with a 'completion portfolio'.
This was a euphemism for an add-on to the manager's selected holdings that
essentially made his fund behave much more like the index!
As Cohen et al conclude "The poor overall performance of mutual fund managers
in the past is not due to a lack of stock-picking ability, but rather to institutional
factors that encourage them to over-diversify". Thus as Sir John Templeton
said, "It is impossible to produce a superior performance unless you do something
different from the majority".
The bottom line is that the EMH nuclear bomb is more of a party popper than
a weapon of mass destruction. The EMH would have driven Sherlock Holmes to
despair. As Holmes opined "It is a capital mistake to theorize before one has
data. Insensibly one begins to twist facts to suit theories, instead of theories
to suit facts".
The EMH, as Shiller puts it, is "one of the most remarkable errors in the
history of economic thought". EMH should be consigned to the dustbin of history.
We need to stop teaching it, and brain washing the innocent. Rob Arnott tells
a lovely story of a speech he was giving to some 200 finance professors. He
asked how many of them taught EMH - pretty much everyone's hand was up. Then
he asked how many of them believed in it....only two hands remained up!
A similar sentiment seems to have been expressed by the recent CFA UK survey
which revealed that 67% of respondents thought that the market failed to behave
rationally. When a journalist asked me what I thought of this, I simply said "About
bloody time". However, 76% said that behavioural finance wasn't yet sufficiently
robust to replace modern portfolio theory (MPT) as the basis of investment
thought. This is, of course, utter nonsense. Successful investors existed long
before EMH and MPT. Indeed, the vast majority of successful long-term investors
are value investors who reject pretty much all the precepts of EMH and MPT.
Will we ever be successful at finally killing off the EMH? I am a pessimist.
As Jeremy Grantham said when asked what investors would learn from this crisis: "In
the short term, a lot. In the medium term, a little. In the long term, nothing
at all. That is the historical precedent". Or as JK Galbraith put it, markets
are characterised by "Extreme brevity of financial memory... There can be few
fields of human endeavour in which history counts for so little as in the world
of finance".
Footnote:
¹ - Two economists have written a paper arguing that the NASDAQ bubble
might not have been a bubble after all - only an academic with no experience
of the real world could ever posit such a thing.
Maine, Tulsa, and Paul McCartney
I am in Maine today with my youngest son Trey (15), who in all likelihood
is once again going to catch more fish than Dad. I guess after going through
it with his six siblings, I should be used to it by now; but he's hitting me
with, "Dad, when can I get my learner's permit? Did you know you have to have
a learner's permit for a whole six month's before you drive? I don't want to
wait until I'm 16." This conversation or variants of it keep coming up. I tell
him I could predict much better when he would get the permit if I knew how
he would do in math this year. You gotta love it.
August 22 is fast approaching. Amanda is getting married to a fine young ex-Marine,
and of course all the family will be there, along with a large guest list.
Seems everyone knows Amanda. It will be a fun two days.
But one day before leaving for Tulsa, I get to visit Penny Lane by way of
a Paul McCartney concert at the new football edifice that is Cowboys Stadium
in Arlington. I looked at the set of songs he is doing, and the majority are
old Beatle favorites. For one night, I will be taken back in time to when I
was as young as my kids and music was intoxicating and a powerful force in
our lives.
I trust you are enjoying your summer. They go by so fast!
Your realizing that he has an internet addiction problem analyst,
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