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Prologue
Mosques in the Clouds
This book is about luck disguised and perceived as non-luck (that is, skills) and, more generally, randomness disguised and perceived as non-randomness (that is, determinism). It manifests itself in the shape of the lucky fool, defined as a person who benefited from a disproportionate share of luck but attributes his success to some other, generally very precise, reason. Such confusion crops up in the most unexpected areas, even science, though not in such an accentuated and obvious manner as it does in the world of business. It is endemic in politics, as it can be encountered in the shape of a country's president discoursing on the jobs that "he" created, "his" recovery, and "his predecessor's" inflation.
We are genetically still very close to our ancestors who roamed the savannah. The formation of our beliefs is fraught with superstitionseven today (I might say, especially today). Just as one day some primitive tribesman scratched his nose, saw rain falling, and developed an elaborate method of scratching his nose to bring on the much-needed rain, we link economic prosperity to some rate cut by the Federal Reserve Board, or the success of a company with the appointment of the new president "at the helm". Bookstores are full of biographies of successful men and women presenting their specific explanation on how they made it big in life (we have an expression, "the right time and the right place" to weaken whatever conclusion can be inferred from them).
This confusion strikes people of different persuasions; the literature professor invests a deep meaning into a mere coincidental occurrence of wordpatterns, while the financial statistician proudly detects "regularities" and "anomalies" in data that are plain random.
At the cost of appearing biased, I have to say that the literary mind can be intentionally prone to the confusion between noise and meaning, that is, between a randomly constructed arrangement and a precisely intended message. However, this causes little harm; few claim that art is a tool of investigation of the Truthrather than an attempt to escape it or make it more palatable. Symbolism is the child of our inability and unwillingness to accept randomness; we give meaning to all manner of shapes; we detect human figures in inkblots. I saw mosques in the clouds announced Arthur Rimbaud the 19th-century French symbolic poet. This interpretation took him to "poetic" Abyssinia (in East Africa), where he was brutalized by a Christian Lebanese slave dealer, contracted syphilis, and lost a leg to gangrene. He gave up poetry in disgust at the age of 19, and died anonymously in a Marseilles hospital ward while still in his thirties. But it was too late. European intellectual life developed what seems to be an irreversible taste for symbolismwe are still paying its price, with psychoanalysis and other fads.
Regrettably, some people play the game too seriously; they are paid to read too much into things. All my life I have suffered the conflict between my love of literature and poetry and my profound allergy to most teachers of literature and "critics". The French poet Paul Valery was surprised to listen to a commentary of his poems that found meanings that had until then escaped him (of course, it was pointed out to him that these were intended by his subconscious).
More generally, we underestimate the share of randomness in about anything, a point that may not merit a bookexcept when it is the specialist who is the fool of all fools. Disturbingly, science has only recently been able to handle randomness (the growth in available information has been exceeded by the expansion of noise). Probability theory is a young arrival in mathematics; probability applied to practice is almost nonexistent as a discipline.
Consider the left and the right columns of Table P. 1. The best way to summarize the major thesis of this book is that it addresses situations (many of them tragicomical) where the left column is mistaken for the right one. The sub-sections also illustrate the key areas of discussion on which this book will be based.
Table P.1 Table of Confusion
Presenting the central distinctions used in the book
GENERAL
LuckSkills
RandomnessDeterminism
ProbabilityCertainty
Belief, conjectureKnowledge, certitude
TheoryReality
Anecdote, coincidenceCausality, law
ForecastProphecy
MARKET PERFORMANCE
Lucky idiotSkilled investor
Survivorship biasMarket outperformance
FINANCE
VolatilityReturn (or drift)
Stochastic variableDeterministic variable
PHYSICS AND ENGINEERING
NoiseSignal
LITERARY CRITICISM
None (literary critics do not seem to have a name for things they do not understand)Symbol
PHILOSOPHY OF SCIENCE
Epistemic probabilityPhysical probability
InductionDeduction
Synthetic propositionAnalytic proposition
The reader may wonder whether the opposite case might not deserve some attention, that is, the situations where non-randomness is mistaken for randomness. Shouldn't we be concerned with situations where patterns and messages may have been ignored? I have two answers. First, I am not overly worried about the existence of undetected patterns. We have been reading lengthy and complex messages in just about any manifestation of nature that presents jaggedness (such as the palm of a hand, the residues at the bottom of Turkish coffee cups, etc.). Armed with home supercomputers and chained processors, and helped by complexity and "chaos" theories, the scientists, semi-scientists, and pseudoscientists will be able to find portents. Second, we need to take into account the costs of mistakes; in my opinion, mistaking the right column for the left one is not as costly as an error in the opposite direction. Even popular opinion warns that bad information is worse than no information at all.
However interesting these areas could be, their discussion would be a tall order. In addition, they are not my current professional specialty. There is one world in which I believe the habit of mistaking luck for skill is most prevalentand most conspicuousand that is the world of trading. By luck or misfortune, that is the world in which I operate. It is my profession, and as such it will form the backbone of this book. It is what I know best. In addition, business presents the best (and most entertaining) laboratory for the understanding of these differences. For it is the area of human undertaking where the confusion is greatest and its effects the most pernicious. For instance, we often have the mistaken impression that a strategy is an excellent strategy, or an entrepreneur a person endowed with "vision", or a trader an excellent trader, only to realize that 99.9% of their past performance is attributable to chance, and chance alone. Ask a profitable investor to explain the reasons for his success; he will offer some deep and convincing interpretation of the results. Frequently, these delusions are intentional and deserve to bear the name "charlatanism".
If there is one cause for this confusion between the left and the right sides of our table, it is our inability to think criticallywe may enjoy presenting conjectures as truth. We are wired to be like that. We will see that our mind is not equipped with the adequate hardware to handle probabilities; such infirmity even strikes the expert, sometimes just the expert. A critical mind, on the other hand, is someone who has the guts, when confronting a given set of information, to attribute a large share of its possible cause to the left column.
The 19th-century cartoon character, pot-bellied bourgeois Monsieur Prudhomme, carried around a large sword with a double intent: primarily to defend the Republic against its enemies, and secondarily to attack it should it stray from its course. In the same manner, this book has two purposes: to defend science (as a light beam across the noise of randomness), and to attack the scientist when he strays from his course (most disasters come from the fact that individual scientists do not have an innate understanding of standard error or a clue about critical thinking). As a practitioner of uncertainty I have seen more than my share of snake-oil salesmen dressed in the garb of scientists. The greatest fools of randomness will be found among these.
This author hates books that can be easily guessed from the table of contentsbut a hint of what comes next seems in order. The book is composed of three parts. The first is an introspection into Solon's warning, as his outburst on rare events became my lifelong motto. In it we meditate on visible and invisible histories. The second presents a collection of probability biases I encountered (and suffered from) in my career in randomnessones that continue to fool me. The third concludes the book with the revelation that perhaps ridding ourselves of our humanity is not in the works; we need tricks, not some grandiose moralizing help. Again the elders can help us with some of their ruses.
Copyright © 2001 Nassim Nicholas Taleb