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The Black Swan

The impact of the highly improbable

Cat: SCI
Pub: 2007

Nassim Nicholas Taleb



The Black Swan - The impact of the highly probable

黒い白鳥 - 最も不確実なことのインパクト

  1. Prologue:
  2. The apprenticeship of an empirical skeptic:
  3. Yevgenia's Black Swan:
  4. The speculator and the prostitute:
  5. 1001 days, or how not to be a sucker:
  6. Confirmation Shmonfirmation!:
  7. The narrative fallacy:
  8. Living in the antechamber of hope:
  9. Giacomo Casanova's unfailing luck; the problem of silent evidence:
  10. The ludic fallacy, or the uncertainty of the nerd:
  11. The scandal of prediction:
  12. How to look for bird poop:
  13. Epistemocracy, a dream:
  14. Appelles the painter, or what do you do if you cannot predict?:
  15. Form mediocristan to extremistan, and black:
  16. The bell curve, that great intellectual fraud:
  17. The aesthetics of randomness:
  18. Locke's madmen, or bell curves in the wrong places:
  19. The uncertainty of the phony:
  20. Half and half, or how to get even with the black swan:
  1. 序文:
  2. 実証的懐疑論者の徒弟期間:
  3. イェフゲニアの黒い白鳥:
  4. 投機家と売春婦:
  5. 1001日または騙されない方法:
  6. 確認と偽確認:
  7. 物語の誤謬:
  8. 希望という待合室に生きる:
  9. ジアコモ・カサノヴァの尽きない幸運;沈黙の証拠問題:
  10. 遊びの誤謬またはオタクの不確実性:
  11. 予測のスキャンダル:
  12. 鳥のフンの探し方:
  13. 認識主義という夢:
  14. 予測不能な場合:
  15. 平均国から極端国へまたその逆へ:
  16. ベルカーブ=巨大な知的詐欺:
  17. ランダムの美学:
  18. 場違いのベルカーブ:
  19. 嘘つきの不確実性:
  20. 半々あるいは黒い白鳥へ仕返し:
Platonicity; Mediocristan vs. Extremistan; Negative empiricism; Confirmation bias; Splitting brains; The Tartar Steppe; The butterfly effect; What is history?; Zipf's law; Gaussian; Fractal;
  • Not only Black Swans in Australia, but other unique animals were unknown probably until 18C; first landed Eurepean reported that in this continent, a bird runs (Emu) and an animal jumps (Kangaroo).
  • This book is all about Black Swans; the random events that under lie our lives.
  • Also, this book seems more persuasive, particularly after 3.11 in 2011 the meltdown of 3 nuclear reactors in Fukushima.
  • 豪州の黒い白鳥に限らず18Cまでは他にも未知の動物がいた。豪州を探査した白人はこの大陸では鳥が走り、獣が跳ぶと報告した。
  • 本書は黒い白鳥という我々の生活に潜むランダムな現象を話題にしている。
  • 特に、2011年の3.11の想定外の惨事はこの黒い白鳥の説の信憑性を感じる。

>Top 0. Prologue:

  • Before the discovery of Australia, the Old World were convinced that all swans were white, which seemed completely confirmed by empirical evidence.
    • It illustrates a sever limitation to our learning from observations or experience and the fragility of our knowledge. One single observation can invalidate a general statement derived from millennia of confirmatory sightings.
    • Black Swan:
      • Rarity: it is an outlier, as it lies outside the ream of regular expectations.
      • Extreme impact: it carries an extreme impact.
      • Retrospective predictability: human nature makes us concoct explanations for its occurrence after the fact.
    • We tend to act as if it does not exist!
      • Go ask your portfolio manager about risk, who will supply a measure that excludes the possibility of the Black Swan.
    • Our blindness with respect to randomness, large deviations.
      • life is the cumulative effect of a handful of significant shocks.
      • compare the significant events to what was expected before their advent. How often did these things occur according to plan?
    • What is surprising is not the magnitude of our forecast errors, but our absence of awareness of it.
    • Our predecessors spent more than 100M years as nonthinking mammals; our brain used on subject too peripheral to matter.
      • We do much less thinking than we believe we do.
  • Life is very unusual:
    • We need to study the rare and extreme events in order to figure out common ones.
      • The bell curve ignores large deviations, cannot handle them, and makes us confident that we have tamed uncertainty.
      • GIF, Great Intellectual Fraud.
  • Platonicity: >Top
    • is our tendency to mistake the map for the territory, to focus on pur and well-defined forms. The difficulty is:
      1. you don't know beforehand where the map will be wrong, and
      2. the mistakes can lead to severe consequences.
  • This implies the need
    • to use the extreme event as a starting point and not treat it as an exception.
    • also make the bolder claim that in spite of our progress in knowledge, or perhaps because of such progress, the future will be increasingly less predictable.

0. 序文:

  • 豪州で黒い白鳥が発見されるまでは旧大陸では白鳥は白いものとの
  • blackswanbeer
  • 黒い白鳥の論理
    • 希有性
    • 強い衝撃
    • 事後予想


  • 日常の意外性
    • ベルカーブ=正規曲線が


  • プラトン主義者:
    • 地図と本物の地面との錯覚
    • 理念型に固執


  • 極端なケースは
    • 例外ではなく
    • 知識の発展故に未来は

>Top 1. The apprenticeship of an empirical skeptic:

  • Levant: eastern Mediterranean city:
    • Levantine cities were mercantile in nature;
    • The mosaic of cultures and religions (Maronites, Armenians, Greco-Syrian Byzantine Orthodox, even Byzantine Catholic, Roman Catholics left over from the Crusades); Moslems (Shiite and Sunny); Drugs, a few Jews.
    • It attracted spies (both Soviet and Western), prostitutes, writers, poets, drug dealers, adventures, compulsive gamblers, tennis players, après-skiers, and merchants.
  • History is opaque: you see what comes out, not the scrip that produces events, the generator of history.
    • Human mind suffers from three ailments:
      1. the illusion of understanding, or how everyone thinks he knows what is going on in a world.
      2. retrospective distortion, or how we can assess matters only after the fact, as if they were in a rearview mirror.
      3. overvaluation of actual information and the handicap of authoritative and learned people, particularly when they create categories when they "Platonify."
  • History does not crawl, it jumps:
    • our minds are wonderful explanation machines, capable of making sense out of almost anything.
    • Who predicted the rise of Christianity as a dominant religion in the Mediterranean basin, and later in the Western world? The Roman chroniclers of that period did not even take note of the new religion.
    • How about the competing religion that emerged 7C later; who forecast that a collection of horsemen would spread their empire and Islamic law from the Indian subcontinent to Spain in just a few years. It was the spread of Islam that carried full unpredictability;
    • The best way to prove the arbitrary character of these categories, and the contagion effect they produce.
      • Today's alliance between Christian fundamentalists and the Israeli lobby would certainly seem puzzling to a 19C intellectual - Christians used to be anti-Semites and Moslems were the protectors of the Jews, whom they preferred to Christians.
      • Libertarians used to be left-wing.
      • Categorizing always produces reduction in true complexity. It is a manifestation of the Black Swan generator, that unshakable Platonicity.

1. 経験的懐疑論への見習い:

  • レバント地方:
    • 地中海東岸の都市
    • 各宗教のるつぼ


  • 歴史は不透明
    • 理解することへの幻想
    • 回顧論的ゆがみ
    • プラトン的理想論による

  • 歴史は歩まない、飛躍する
    • 何でも説明したがる性癖
    • キリスト教の布教はローマ帝国も予想外
    • 7C以降のイスラム教の布教も驚異的
    • 19Cには、キリスト教は反ユダヤ教で、イスラム教がむしろユダヤ教を保護

>Top 2. Yevgenia's Black Swan:

  • 5 years ago, Yevgenia Nikolayevna Krasnovwa was an obscure and unpublished novelist. She was a neuroscientist with an interest in philosophy.
    • Publishers were confused by her manuscript. She could not even answer their first question; "Is this fiction or nonfiction?" "Who is this book written for? ""Amateurs write for themselves, professionals writ for others." "Bookstores do not like to be confused and need to know where to place a book on the shelves."
  • Yevgenia ended up posting the entire manuscript of her main book, A story of Recursion, on the Web.
    • It took 5 years for Yevgenia to graduate from the egomaniac, stubborn, and difficult to deal with category to persevering, resolute, painstaking and fiercely independent.
    • Many of the editors she later met blamed her for not coming to them, convinced that they would have immediately seen the merit in her work.

2. イェフゲニアの黒鳥:

  • 出版には明確な分類が必要か

>Top 3. The speculator and the prostitute:

  • Mediocristan vs. Extremistan: (→Table) >Top
  • The best (worst) advice:
    • Most consisted recommendations such as "be measured and reasonable in your statements"
    • The most important advice was, in retrospect, bad, but it was also, paradoxically, the most consequential.
    • How did career advice lead to such ideas about the nature of uncertainty? Some professions, such as dentists, consultants, or massage professionals, cannot be scaled; there is a cap on the number of patients or clients you can see in a given period of time. A prostitute works by the hour and are paid by the hour.
      • Your revenue depends on your continuous efforts more than on the quality of your decisions.
    • If you are an idea person, you do not have to work hard, only think intensely.
      • So the distinction between writer and banker, speculator and doctor, fraudster and prostitute, is a helpful way to kook at the world of activities.
      • It separates those professions in which one can add zeroes of income with no greater labor from those in which one needs to add labor and time - in other words, those subjected to gravity.
    • Furthermore, the big transition in social life came not with the gramophone, but when someone had the great but unjust idea to invent the alphabet, thus allowing us to store information and reproduce it.
      • It accelerate further when starting a printing press, promoting texts across boundaries and triggering into a winner-take-all ecology.
      • in the arts, cinema, things are far more vicious. What we call "talent" generally comes from success rather than its opposite. The move makes the actor, and a large dose of nonlinear luck makes the move.
    • Globalization has allowed US to specialize in the creative aspect of things, the production of concepts and ideas, that is, the scalable part of the products.
    • Extremists does not always imply Black Swans. Some events can be rare and consequential, but somewhat predictable; they are new-Black Swans (gray swans Mandelbrotian randomness)
      • The category encompasses the randomness that produces phenomena commonly known by terms such as scalable, scale-invariant, power laws, Paret-Zipf laws, Yule's laws, Paretian-stable processes, Levy-stable, and fractal laws.

3. 投機家と売春婦:

Mediocristan Extremistan
nonscalable scalable
mild or type-1 randomness wild or type-2 randomness
typical member is mediocre typical is either giant or dwarf; no typical member
winners get a small segment winners take all
audience before gramophone today's audience
impervious to the Black Swan vulnerable to the Black Swan
subject to gravity no physical constraints
utopian equality dominated by extreme inequality
total is not determined by a single instance total will be determined by extreme events
can gent to know what's going ob by observation takes long time to know what's going on
tyranny of the collective tyranny of the accidental
easy to predict from what you see hard to predict from past information
history crawls history makes jumps
events are distributed by bell curve distribution is either gray Swans or totally intractable Black Swans

>Top 4. 1001 days, or how not to be a sucker:

  • How to learn from the turkey:
    • Bertrand Russell: 'Problem of Inductive Knowledge'.
    • Consider a turkey that is fed every day. (Problem of induction)
      • Every single feeding will firm up the bird's belief that it it the general rule of life to be fed every day by friendly members of the human race.
      • On the afternoon of the Wednesday before thanksgiving, something unexpected will happen to the turkey. It will incur a revision of belief.
      • Consider the case of integrated German Jews in 1930, or the population of Lebanon.
      • A big change takes place that is completely unprepared for the past.
    • Prototypical case of the problem of induction as encountered in real life. You observe a hypothetical variable for 1000 days; booksales, blood pressure, crimes, personal income, a given stock, interest on a loan. You subsequently derive solely from past data a few conclusions; for the next 1000, or even 5000 days. On the 1001st day - boom!
      • But in all my experience, I have never been in any accident ... of any sort worth speaking about. I have seen but one vessel in distress in all my years at sea. ... I never saw a wreck and never have been wrecked nor was I ever in any predicament that threatened to end in disaster of any sort. - E. J. Smith, 1907, Captain, RMS Titanic.
        • Titanic sank in 1912; became the most talked about shipwreck in history.
    • Trained to be dull:
      • Banks hire dull people and train them to be even more dull.
      • 1982 summer: Large American banks lost close to all their past cumulative earnings. Lending to South & Central America.
      • early 1990s: real-estate collapse.
      • 1998: Long-Term Capital Management (LTCM)

4. 1001日または騙されない方法:

  • 七面鳥の教訓 :
    • 1000日間飼育の翌日



  • 想定外の出来事
    • タイタニック船長の日記


  • 鈍感になるための訓練

>Top 5. Confirmation Shmonfirmation!

  • Evidence:
    • Naïve empiricism: we have a natural tendency to look for instances that confirm our story and our vision of the world.
    • Negative empiricism: >Top
      • We can get closer to the truth by negative instances, not by verification!. It is misleading to build a general rule from observed facts.
    • Falsification:
      • to falsify is to prove wrong.
      • to distinguish between science and nonscience. This idea about the symmetry of knowledge is so like by practitioners.
      • it is not so easy to falsify, i.e., to stage that something is wrong with full certainty.
      • Popper introduced the mechanism of conjectures and refutations. You formulate a bold conjecture and you start looking for the observation that would prove you wrong.
  • Confirmation bias: >Top
    • Disconfirming instances are far more powerful in establishing truth. Yet we tend to not be aware of this property.
    • P.C. Wason, psychologist presented three number sequence 2,4,6 and asked to guess the rule generating it. The experimenter would respond 'yes' or 'no' consistent with the rule.
      • The correct rule was "numbers in ascending order."
      • Rookies look for confirmatory instances instead of falsifying ones.
      • Sadly, the notion of corroboration is rooted in our intellectual habits and discourse
  • Not everything:
    • It seems that we are endowed with specific and elaborate inductive instincts showing us the way.
      • Studied of infant behavior that we come equipped with mental machinery that causes us to selectively generalize from experiences (i.e., to selective acquire inductive learning in some domains, but remain skeptical in others.)

5. 確認と偽確認:

  • 証拠
    • 無垢な経験論
    • 歪曲


  • 確認バイアス:
    • 2, 4, 6の連続数の規則?


  • 全てに当てはまらないもの
    • 人間の脳の性癖

>Top 6. The narrative fallacy:

  • At a conference 2004 in Rome:
    • Italian professor: "I am a huge fan of your ideas... Had you grown up in a Protestant society where people are told that efforts are linked to rewards and individual responsibility is emphasized, you would never have seen the world in such a manner. You were able to see luck and separate cause and effort because of your Eastern Orthodox Mediterranean heritage."
    • We like stories, we like to summarized, and we like to simplify, i.e., to reduce the dimension of matters.
      • The fallacy is associated with our vulnerability to overinterpretation and our predilection for compact stories over raw truth. It severely distorts our mental representation of the world; it is particularly acute when it comes to the rare event.
      • The narrative fallacy addresses our limited ability to look at sequences of facts without weaving an explanation into them, or, equivalently, forcing a logical link, an arrow of relationship, upon them. Explanations bind facts together. They make them all the more easily remembered; they help them make more sense. Where this propensity can go wrong is when it increases our impression of understanding.
  • Splitting brains: >Top
    • It takes considerable effort to see facts while withholding judgment and resisting explanations. And this theorizing disease is rarely under our control.
      • Try to be a true skeptic with respect to your interpretations and you will be worn out in not time. You will also be humiliated for resisting to theorize.
    • Post hoc rationalization:
      • In an experiment, psychologists asked women to select from among 12 pairs of nylon stockings; then asked the women their reasons for their choices.
      • Texture, feel, and color featured, etc.
      • All the pairs of stocks were in fact identical.
      • Does this suggest that we are better at explaining than at understanding?
    • The idea that the left brain controls language may not be so accurate; the left brain seems more precisely to be where pattern interpretation resides; the right brain deal with novelty. it tends to see the gestalt (the general, or the forest), in a parallel mode, while the left brain is concerned with the trees, in a serial mode.
  • Dopamine:
    • Dopamine also regulates moods and supplies an internal reward system in the brain. A higher concentration of dopamine appears to lower skepticism and result in greater vulnerability to pattern detection.
      • The person become vulnerable to all manner of fads, such as astrology, superstitions, economics, and tarot-card reading.
  • Kolmogorov complexity:
    • A pattern is obviously more compact than raw information. You looked into the book and found a rule.
    • The more random information is, the greater the dimensionality, and thus the more difficult to summarize. The more you summarize, the more order you put in, the less randomness
      • Hence the same condition that makes us simplify pushes us to think that the world is less random than it actually is.
      • And the Black Swan is what we leave out of simplification.
  • Remembrance of things:
    • Conventional wisdom holds that memory is like a serial recording device like a computer diskette.
    • In reality, memory is dynamic - not static - like a paper on which new texts will be continuously recorded, thanks to the power of posterior information; a type of parchment on which old text can be erased and new ones written over them.
    • You remember the last time you remembered the event and, without realizing it, change the story at every subsequent remembrance.
  • The Shortcuts:
    • System-1: The experiential one, is effortless, automatic, fast, opaque, parallel-processed, and can lend itself to errors. It is what we call "intuition."
    • System-2: The cogitative one, is what we normally call thinking. It is effortful, reasoned, slow, logical, serial, progressive, and self-aware. It makes fewer mistakes than the experiential system, and, since you know how you derived your result, you can retrace your steps and correct them in an adaptive manner.
      • Emotions are assumed to be the weapon System-1 uses to direct us and force us to act quickly. It mediates risk avoidance far more effectively than our cognitive system. Indeed, neurobiologists who have studied the emotional system show ho it often reacts to the presence of danger long before we are consciously aware of it - we experience fear and start reacting a few milliseconds before we realize that we are facing a snake.
      • Much of the trouble with human nature resides in our inability to use much of System-2, or to use it in a prolonged way without having to take a long beach vacation.
      • The way to avoid the ills of the narrative fallacy is to favor experimentation over storytelling, experience over history, and clinical knowledge over theories.

6. 物語の誤謬:

  • ローマでの学会(2004):
    • 原因と結果が結びつかない



  • 分裂する脳:
    • 判断を保留するには努力が
    • 事後の合理化
      • 12足のストッキング選定の理由


  • ドーパミン:
    • 脳内ムード作りと報酬


  • Kolmogorovの複雑性:
    • パターンは元情報の圧縮
    • ランダム情報は多次元で
    • 要約することで次元を下げる
    • 黒鳥化現象も簡略化の中で発生した。


  • 物事の記憶:
    • 記憶はコンピュータの記憶のように連続的か
    • 実際にはもっと動的で書き換え可能


  • ショートカット
    • システム1:
    • システム2:
    • システム1の情緒システムの方が危険に対し反射的に反応

>Top 7. Living in the antechamber of hope:

  • Where the relevant is the sensational:
    • Our intuitions are not cut out for nonlinearities.
    • In a primitive environment, the relevant is the sensational. When we try to collect information about the world around us, we tend to be guided by out biology, and our attention flows effortlessly toward the sensational - not the relevant so much as the sensational - not the relevant so much as the sensational.
    • Somehow the guidance system has gone wrong in the process o our coevolution with our habitat - it was transplanted into a world in which the relevant is often boring, nonsensational.
    • Researchers spent some time dealing with this notion of gratification; neurology has been enlightening us about the tension between the notions of immediate rewards and delayed ones.
      • Higher mind; which distinguishes us from animals, can override our animal instinct, which asks for immediate rewards. We are a little better than animals, but perhaps no by much. and not all of the time.
  • Process over results:
    • Those who claim that they value process over result are not telling the whole truth.
      • We often hear the semi-lie that writers do not writ for glory, that artists create for the sake of art, because the activity is its own reward. But this does not man that artists do not crave some form of attention, or that they would not be better off if they got some publicity…
    • Black Swan hunters:
      • are not the one who make the bucks.
      • Return on independent inventions are far lower than those on venture capital.
      • This may apply to all concentrated businesses: VC do better than entrepreneurs, but publishers do better than writers, dealers do better than artists, and science does better than scientists. (about 50% of scientific and scholarly papers, costing months, sometimes years, of effort, are never truly read.)
    • Positive affect:
      • good news is good news first; how good matter rather little. So to have a pleasant life you should spread these small 'affects' across time as evenly as possible.
      • Plenty of mildly good news i preferable to one single lump of great news.
    • Hedonic calculus:
      • it does not pay to shoot for one large win.
      • Mother Nature destined us to derive enjoyment from a steady flow of pleasant small, but frequent, rewards - a little bit here, a little bit there; in the form of food , water and more private.
      • The problem, is that we do no live in an environment where results are delivered in a steady manner.
        • Black Swans dominate much of human history. It is unfortunate that the right strategy for our current environment may not offer internal rewards and positive feedback.
  • "The Desert of the Tartars", or "The Tartar Steppe": >Top
    • Giovanni Drogo is a man of promise; just graduated from the military academy with the rank of junior officer, and active life is just starting.
    • But things do not turn out as planned; his initial 4-year assignment is a remote outpost, the Bastiani fortress, protecting the nation from the Tartars likely to invade from the border desert.
    • The fortress is located a few days by horseback from the town; there is nothing but bareness around it - none of the social buzz that a man of his age could look forward to.
    • Drogo thinks that his assignment in the outpost is temporary. Later, back in town, in his impeccably ironed uniform and with his athletic figure, few ladies will be able to resist him.
    • He discovers a loophole, a way to be transferred after only 4 months.
    • At the very last minute, however, Drogo takes a glance at the desert from the window of the medical office and decides to extend his stay. Something in the walls of the fort and the silent landscape ensnares him.
    • The appeal of the fort and waiting fro the attackers gradually become his only reason to exist. They are so focused that, on rare occasions, they can detect the most insignificant stray animal that appears at the edge of the desert and mistake it for an enemy attack. Drogo spends the rest of his life extending his stay, delaying the beginning of his life in the city - 35 years of pure hope, spent in the grip of the idea that one day, from the remote hills that no human has ever crossed, the attacker will eventually emerge and help him rise to the occasion.
    • At the end of the nove we see Drogo dying in a roadsid inn as the envent for which he has waited all his life takes place. He has missed it.
    • the Black Swan as the outlier, the important event tha tis not expected to happen. But consider the opposite; the unexpected event that you very badly want to happen. Drogo is obsessed and blinded by the possiboility of an unlikely event; that rare occurrence is his raison d'être.
      • A Black Swan is an sysmmetry in consequences - either positive or negative. For Drogo the consequences were 35 years spent waiting in the antechamber of hope for just a few randomly distributed hours of glory - which he ended up missing.
  • Bleed or Blowup:
    • Extremistan are extremely dangerous but do no appear to be so beforehand, since they hid and delay their risks - so suckers think they are 'safe.' It is indeed a property of Extremistan to look less risky, in the short run, than it really is.
    • Some business bets in which one wins big but infrequently, yet loses small but frequently, are worth making if others are suckers for them and if you have the personal and intellectual stamina.
      • A strategy called 'bleed'; You lose steadily, daily, for a long time, except when some event takes place for which you get paid disproportionately well.
    • The hippocampus is the structure where memory is supposedly controlled. It is the most plastic part of the brain; it is also the part that is assumed to absorb all the damage from repeated insults like chronic stress we experience daily from small doses of negative feelings - as opposed to the invigorating 'good stress' of the tiger popping up occasionally in your living room.
      • Contrary to popular belief, these small, seemingly harmless stressors do no strengthen you; they can amputate part of you self.
    • One day Nero sat down and listened very calmly to the evaluation of his supervisor. When Net was handed the evaluation from he tore it into small pieces in front of him. He did this very slowly, accentuating the contrast between the nature of the act and the tranquility with which the tore the paper. Nero focused on his undramatic, slow-motion act. He knew that he would either be fired or left alone. He was left alone.

7. 希望という待合室に生きる:

  • 直感は非線形向きではない
  • つまらないことの多い世界に適応






  • ポジティブ感情
  • 享楽計算:













  • "タタール人の砂漠"
    • 辺境に35年間駐屯した将校の物語



  • 黒い白鳥は外れ値:期待されていない事象
    • 待つが花
    • 結果は非対称





  • 流血か爆破か
    • 極端国のやり方:安全を過小評価

>Top 8. Giacomo Casnova's unfailing luck; the problem of silent evidence:

  • The story of the drowned worshippers:
    • more than 2000 years ago, Marcus Tullius Cicero, presented the following story:
      • One Diagoras, a nonbeliever in the gods, was shown painted tablets bearing the portraits of some worshippers who prayed, then survived a subsequent shipwreck. The implication was that praying protects you from drowning.
      • Diagoras asked, "Where were the pictures of those who prayed then drowned?"
      • This can fool the casual observer into believing in miracles.
    • As drowned worshippers do not write histories of their experiences, so it is with the losers in history, whether people or ideas.
      • Remarkably, historians and other scholars in the humanities who need to understand silent evidence the most do no seem to have a name for it.
      • As for journalist, who are industrial producers of the distortion.
      • The term bias also indicates the condition's potentially quantifiable nature.
  • The cemetery of letters:
    • The Phoenicians produced no literature, although they allegedly invented the alphabet.
    • They are more interested in commerce than in the arts. Accordingly, the Phoenician invention of the alphabet served the lower purpose of commercial record keeping rather than the more noble purpose. of literary production. (merchant race)
  • Balzac:
    • "Nightingale" was given by bookstores to those works residing on the shelves in the solitary depths of their shops.
    • Balzac presents to us the sorry state of contemporary literature when Lucien's manuscript is rejected by a publisher who has never read it; later on, when Lucian's reputation has developed, the very same manuscript is accepted by another publisher who did not read it either! The work itself was a secondary consideration.
  • How to become a millionaire:
    • to figure out the skills required for hotshotness:
      • courage, risk taking, optimism, and so on.
      • the entire notion of biography is grounded in the arbitrary ascription of a causal relation between specified traits and subsequent events.
    • Now consider the cemetery. The graveyard of failed persons will be full of people who shared the following traits; courage, risk taking, optimism, etc. Just like the population of millionaires. There may be some differences in skill, but what truly separated the two is luck. Plain luck.
      • Scalable profession is not a good idea, simply because there are far too fewer winners in these professions. These professions produce a large cemetery; the pool of starving actors is larger than the one of starving accountants, even if you assume that, on average, they earn the same income.
  • The anthropic bias:
    • it points out the gravity of our misunderstanding of historical stability.
    • Consider our own fates:
      • The odds of any of us being in existence are so low that our being here cannot be attributed to an accident of fate.: it could not come from luck.
      • However, our presence in the sample completely vitiates the computation of the odds.
      • The problem here with the universe and the human race is that we are the surviving Casanovas.
      • Form the reference point of the beginning cohort, this is not a big deal.; a long string of wins will appear to be too extraordinary an occurrence o be explained by luck. Note that a history is just a series of number through time.
  • The biggest problem with the educational system:
    • it forces students to squeeze explanations out of subject matters and shames them for withholding judgement, for uttering the "I don't know."
    • Note here that I am not saying causes do not exits; do not use this argument to avoid trying to learn from history.

8. ジアコモ・カサノヴァの尽きない幸運:沈黙の証拠問題:

  • 溺れた信者の話
    • 溺れて助かった話のみ


  • 文字の墓場:
    • フェニキア人は商業民族
    • アルファベットは発明したが文学は残さず



>Top 9. The ludic fallacy, or the uncertainty of the nerd:

  • Uncertainty of the nerd:
    • We tend to underestimate the role of luck in life in general, we tend to overestimate it in games of chance.
      • The gambling building is inside the Platonic fold; life stands outside of it.
  • Gambling with the wrong dice:
    • I learned that the gambling building too was outside the Platonic fold.
    • The casino's risk management:
      • sufficiently diversified across the different tables to not have to worry about taking a hit from an extremely lucky gambler.
      • all they had to do was control "whales", can swing several million dollar in a gambling.
    • Four largest losses incurred or narrowly avoided by the casino:
      1. $100M: an irreplaceable performer in their main show was maimed by a tiger.
      2. A disgruntled contractor made an attempt to dynamite the casino.
      3. The employee was supposed to mail special forms with IRS documenting a gambler's profit it it exceeds a given amount, instead, for completely unexplainable reasons, in boxes under his desk for years without anyone noticing.
      4. Kidnaping of the casino owner's daughter; in order to secure cash for the ransom, to violate gambling laws by dipping into the casino coffers.
  • Distance from primates:
    • A simple step to a higher form of life:
      • You may have to denarrate, shut down the TV set, minimize time spent reading newspapers, ignore the blogs.
      • Train you reasoning abilities to control you decisions; nudge System-1 (heuristic system) out of the important ones.
      • Training yourself to spot the difference between the sensational and the empirical.
      • Bear in mind how shallow we are with probability, the mother of all abstract notions.
      • To focus is a great virtue if you are a watch repairman, a brain surgeon, or a chess player. But this "focus" make you a sucker.

9. 遊びの誤謬またはオタクの不確実性:

>Top 10. The scandal of prediction:

  • Excel spreadsheets:
    • In precomputer days, projections remained vague and qualitative; it was a strain to push scenarios into the future. It took pencils, erasers, reams of paper, and hug wastebaskets.
    • But things changed with the intrusion of the spreadsheet. Sales projection effortlessly extending ad infinitum!: losing its vagueness and abstraction and becoming what philosophers call reified, invested with concreteness. It takes on a new life as a tangible object.
  • Anchoring mechanism discovered by Danny Kahneman and Amos Tversky:
    • We use reference points in our heads, say sales projections, and start building beliefs around them because less mental effort is needed to compare an idea to a reference point than to evaluate it in the absolute (System-1 at work!). We cannot work without a point of reference
    • This is no different from a starting point in a bargaining episode; you open with high number. I want $1M for this house; the bider will answer only $850K.
  • Problem of prediction:
    • its inherent limitation; have little to do with human nature, but instead arise from the very nature of information itself.
    • Black Swan has three attributes: 1) unpredictability, 2) consequences, and 3) retrospective explainability.

10. 予測のスキャンダル:

  • Excel登場後、予測の可視化


  • 不確実性の心理学:


  • 黒い白鳥の特徴:
    • 予測不可能性
    • 重大影響性
    • 遡及説明可能性

>Top 11. How to look for bird poop:

  • 5-year business plan:
    • Being an executive does not require very developed frontal lobes, but rather a combination of charisma, a capacity to sustain boredom, and the ability to shallowly perform on harrying schedules.
    • They wanted to have "vision." But then an event occurred that was not in the previous 5-year plan; today their replacements are still meeting to work on the next 5-year plan. We never learn.
  • Heinri Poíncaré: Nth billiard ball:
  • Difficulty in forecasting in terms of branches growing out of a tree; at every fork we have a multiplication of new branches:
    • 1st impact: a ball at rest, can computer the resistance of the table and can gauge the strength of the impact.
    • 2nd impact: be more careful about the initial states.
    • 9th impact: need to take into account the gravitational pull of someone standing next to the table.
    • 56th impact; every single elementary particle of the universe needs to be present in your assumptions!
  • The butterfly effect: >Top
    • a butterfly moving its wings in India could cause a hurricane in NY, two years later.
    • Edward Lorenz in 1960s;
    • computer model of weather dynamics:
      • he tried to repeat the same stimulation with the exact same model , but got wildly different result.
      • he initially attributed these differences to a computer bug or a calculation error.
      • then he realized that the consequential divergence in his results arose not from error, but from a small rounding in the input parameters.
  • Scattering: (> Fig.)
    • how the second bounce, variations in the initial conditions can lead to extremely divergent results.
  • Hayek:
    • a true forecast is done organically by a system, not by fiat.
    • one single institution, the central planner, cannot aggregate knowledge; many important pieces of information will be missing. But society as a whole will be able to integrate into its functioning these multiple pieces of information.
  • Riddle of induction:
    • We project a straight line only because we have a linear model in our head.

11. 鳥のフンの探し方:

  • 役立たぬ5カ年計画
  • 散乱:
  • scattering



  • プロジェクト予測には線型モデルしかないのか

>Top 12. Epistemocracy, a dream

  • Epistemocracy:
    • Everyone has an idea of utopia; equality, universal justice, freedom from oppression, freedom from work.
    • Utopia is an epistemocracy as society in which anyone of rank is an epistemocrat, and where epistemocrats manage to be elected; a society governed from the basis of the awareness of ignorance, not knowledge.
      • People need to be blinded by knowledge - we are made to follow leaders who can gather people together because the advantages of being in groups trump the disadvantages of being alone.
  • Prediction, Misprediction, and Happiness:
    • The kind of misprediction with respect both pleasant and unpleasant events.
      • We have evidence of a mental block and distortions in the way we fail to learn from our past errors in projecting the future of our affect stage.
      • We grossly overestimate the length of the effect o f misfortune on our lives.
      • You may feel a sting, but it will not be as bad as you expect. This kind of misprediction may have a purpose; to motivate us to perform important acts and to prevent us from taking certain unnecessary risks.
      • We humans are supposed to fool ourselves a little bit here and there.; to orient us favorably toward the future.
    • History is useful for the thrill of knowing the past, and for the narrative, provide it remains a harmless narrative.
      • History is certainly not a place to theorize or deprive general knowledge, not is it meant to help in the future, without some caution.
      • We can get plenty of illusions of knowledge along with it.
    • What is history?: >Top
      • Edward Hallet Carr: explicitly pursuing causation.
      • Herodotus: to preserve a memory of the deeds of the Greeks and barbarians, and in particular beyond everything else, to give a cause to their fighting one another.
      • All theoreticians of history, whether Ibn Khaldoun, Marks, Hegel, enumeration of accounts to be enjoyed with minimal theorizing, the more we get into trouble. Are we so plagued with the narrative fallacy?

12. 認識主義という夢:

  • Epistemology: the theory of knowledge; investigation of what distiguies justified belief from opinion.


  • 予測、誤解、幸福


  • 歴史の役割:
    • 過去の認識と

>Top 13. Appelles the painter, or what do you do if you cannot predict?

  • Nobody knows anything: here are the tricks.
    1. Make a distinction between positive contingencies and negative ones. The lack of predictability can be extremely beneficial and those where the failure to understand the future caused haram. There are both positive and negative Black Swans.
    2. Don't look for the precise and the local. Simply, do not be narrow-minded. Do not try to predict precise Black Swans - it tends to make you more vulnerable to the ones you di not predict. Invest in preparedness, not in prediction.
    3. Seize any opportunity, or anything that looks like opportunity. They are are, much rarer than you think. Remember that positive Black Swans have a necessary first step; you need to be exposed to them. Many people do not realize that they are getting a lucky break in life when they get it.1
    4. Beware of precise plans by governments. Let government predict but do not set much store by what they say. The interest of these civil servants is to survive and self-perpetuate - not to get to the truth.
    5. Do not waste your time trying to fight forecasters, stock analysts, economists, and social scientists except to play pranks on them. They are considerably easy to make fun of , and may get angry quite readily. People will continue to predict foolishly, especially if they are paid for it, and you cannot put an end to institutionalized frauds.

13. 予測不能な場合:

  • 正と負の黒い白鳥がいる。
  • 正確さを求め狭量になるな。
  • あらゆる機会を掴むべし
  • 政府予測には真に受けるな

>Top 14. From Mediocristan to Extremistan, and back:

  • Lingua Franca:
    • Presence in biology of the so-called power laws.
    • Zipf's law in 1940s: >Top
      • the more you use a work, the less effortful you will find it to use that word again, so borrow words from your private dictionary in proportion to their past use.
      • This explains why out of the 6000 main words in English, only a few hundred constitute the bulk of what is used in writings, and even fewer appear regular in conversation.
      • Likewise, the more people aggregate in a particular city, the more likely a stranger will be to pick that city as his destination The big get bigger and the small say small, or get relatively smaller.
      • English usage will spread like an epidemic, and other languages will be rapidly dislodged.
  • Long tail:
    • seems to be the exact opposite of the concentration implied by scalability.
    • the long tail implied that the small guys, collectively, should control a large segment of culture and commerce, thanks to the niches and subspecialties that can now survive thanks to the Internet.
    • it can also imply a large measure of inequality; a large base of small guys and a very small number of supergiants; double tails - a large tail of the small guys, a small tail of the big guys.
    • the long tail is a by-product of Extremistan that makes it somewhat less unfair; the world is made no less unfair for the little guy, but it now becomes extremely unfair for the big man. Nobody is truly established. The little guy is very subversive.

14. 平均国から極端国へまたその逆へ:

  • 生物界は冪乗則
  • Zipfの法則
  • 世界語英語



  • ロングテール:
  • 不平等さの象徴

>Top 15. The bell curve, that great intellectual fraud

  • Grass and trees:
    • Traditional Gaussian way of looking at the world: >Top
      • focusing on the ordinary, and then deals with exceptions or outliers as ancillaries.
    • Gaussian approach in variables fro which there is a rational reason for the largest not to be too far away from the average.
      • if there is gravity pulling number down, or if there are physical limitations preventing very large observations, we end up in Mediocristan.
      • The average will always contain both kinds, giants and dwarves, so that neither should be too rare - unless you get a megagiant or a microdwarf on very rare occasion.
      • The rarer the event, the higher the error in our estimation of its probability even when using the Gaussian.
    • There are other notions that have little or no significance outside of the Gaussian; correlation and regression.
  • Ubiquity of the Gaussian:
    • Gaussian bell curve is not ubiquitous in real life; but a problem in our minds, stemming from the way we look at it.
    • Many people accepted my Black Swan idea but could not take it to its logical conclusion
      • to go the extra step requires courage, commitment, an ability to connect the dots, a desire to understand randomness fully. It also means not accepting other people's wisdom as gospel.

15. ベルカーブ=巨大な知的詐欺:

  • 草と木
  • In Mediocristan, as sample size incrses, the distributio will be narrower:
  • bellcurves

>Top 16. The aesthetics of randomness

  • Logic of fractal randomness: >Top
    • Mandelbrot: 'The fractal geometry of nature'; spread through artistic circles and led to studies in aesthetics, architectural design, even large industrial applications.
    • Visual arts: Most computer-generated objects are now based on some version of the Mandelbrotian fractal. We can also see fractal in architecture, paintings, and many works of visual art.
    • Music: Slowly hum the four-note opening of Beethoven's 5th Symphony. Then replace each individual note with the same four note opening, so that you end up with a measure of 16 notes.
    • Poetry: Emily Dickinson's poetry is fractal; the large resembles the small. A consciously made assemblage of dictions, metres, rhetorics, gestures, and tones.
  • Assumed exponents for various phenomena:
  • Phenomenon Assumed exponent Share of
    top 1%
    Share of
    top 20%
    Intensity of solar flares


    Intensity of wars 0.8    
    Number of persons per family name 1.0 99.99% 99.99%
    Net worth of Americans 1.1 66% 86%
    Frequency of use of words 1.2 47% 76%
    Telephone calls received 1.22    
    Population of US cities 1.3 34% 69%
    Number of hits on websites 1.4 27% 63%
    Number of books sold in US 1.5 22% 58%
    Company size 1.5
    People killed in terrorist attacks 2.0 or lower 10% 45%
    Diameter of moon craters 2.14    
      2.5 6% 38%
    Magnitude of earthquakes 2.8    
    Market moves 3.0 or lower 4.6% 34%
  • Remarks:
    • Look how sensitive the process is: between 1.1 and 1.3 you go from 66% of the total to 34%. Just a 0.2 difference in the exponent changes that result dramatically.
    • Only 96 books a year will sell more than 250,000 copies, and the exponent is around 1.5.
    • You can extrapolate to estimate that around 34 books will sell more than 500,000 copies; and around 12 books more than a million copies.
      • 96×(500000/250000)^(-1.5) = 34
      • 96×(1000000/250000)^(-1.5) = 34
  • Where is the Gray Swan?
    • I have written about the Black Swan. this is not because I am in love with the Black Swan.
    • I hate most of the unfairness and damage it causes. Thus I'd like to eliminate many Black Swans, or at least to mitigate their effects and be protected from them.
    • A Gray Swan concerns modelable extreme events, a Black Swan is about unknown unknowns.
    • French 'hasard' and 'fortuit':
      • hasard: from Arabic az-zahr, implies like alea dice - tractable randomness
      • fortuit is Black Swan - purely accidental and unforeseen.

16. 1333 - 1568: 室町時代:

  • フラクタル分布の論理
  • 諸現象の冪値 (←表)



  • 諸現象の冪乗法則


















  • 灰色の白鳥はどこに?



  • 仏語の
    hasarad: 偶然、運
    fortuit: 不可抗力

>Top 17. Locke's madmen, or bell curves in the wrong places.

  • Robert Merton, Jr., and Myron Scholes were founding partners in LTCM (Long-Term Capital Management)
    • The idea of portfolio theory inspired their risk management of possible outcomes.
    • In summer 1998, a combination of large events, triggered by a Russian financial crisis, took place that lay outside their models.
    • It was just a Black Swan. LTCM went bust and almost took down the entire financial system with it, as the exposures were massive. Since their models ruled out the possibility of large deviations, they allowed themselves to take a monstrous amount of risk. The ideas of Merton and Scholes were starting to go bust.
  • Two ways to approach randomness:
  • Skeptical empiricism Platonic approach
    interested in outside Platonic fold focus on inside of Platonic fold
    have guts to say 'I don't know.' these models are all we have.
    Black Swan as a dominant source or randomness ordinary fluctuations as a dominant source of randomness
    bottom-up top-down
    prefers to be broadly right precisely wrong
    minimal theory, considers theorizing as a disease to resist everything needs to fit general socioeconomic model
    doesn't believe we can compute probabilities can compute probabilities
    develops intuitions from practice, goes from observations to books relies on scientific papers, goes from books to practice
    not inspired by any science inspired by physics
    ideas based on skepticism, on the unread books ideas based on beliefs, on what they think they know
    assumes Extremistan as a starting point assumes Mediocristan as a starting point
    seeks to be approximately right across a broad set of eventualities seeks to be perfectly right in a narrow model, under precise assumptions

17. 場違いのベルカーブ:

  • Merton & Scholesの
  • LTCMの破産:


  • 懐疑的経験主義
    • わからないこと多い
    • ボトムアップ
    • 最小理論
    • 確率は計算可能とは限らない
    • 観察に依存
    • 科学には懐疑的
    • 極論から入る
    • 偶発の連続
  • 理想主義的アプローチ
    • 完璧主義
    • トップダウン
    • 一般論がすべて
    • 確率は計算可能
    • 書籍に依存
    • 物理法則依存
    • 平均重視
    • 正確な予測

>Top 18. The uncertainty of the phony:

  • Ludic fallacy redux:
    • The dice average out so quickly that I can say with certainty that the casino will beat me in the very near long run at, say, roulette.
    • The more you extend the period (or reduce the size of the bets) the more randomness , by virtue of averaging, drops out of these gambling constructs.
    • The ludic fallacy is present in; random walk, dice throwing, coin flipping, the infamous digital heads or tails, Brownian motion, etc.

18. 嘘つきの不確実性:

  • ギャンブルの誤謬
    • 大数の法則に負ける

>Top 19. Half and half or how to get even with the Black Swan:

  • When missing a train is painless:
    • In refusing to run to catch trains, I have felt the true value of elegance and aesthetics in behavior, a sense of being in control of my time, my schedule, and my life. Missing a train is only painful if you run after it!
    • Likewise, not matching the idea of success others expect for you is only painful if that's what you are seeking.
    • You stand above the rat race and the pecking order, not outside of it, if you do so by choice.
    • Quitting a high-paying position, if it is your decision, will seem a better payoff than the utility of the money involved. You have far more control over your life if you decide on your criterion by yourself.
  • We are quick to forget that just being alive is an extraordinary piece of good luck.

19. 半々あるいは黒い白鳥への仕返し

  • 列車を逃すのを苦痛にしない。追いかけるのは美学に反する。
  • 自分の生き様は自分で決定する。それはお金では買えない。
  • 行きていること自体がとてつもなく幸運であることを忘れがち。
  • In geological scale, such as a million years of period, much more drastic catastrophe occurs; continental drift, mountain building, change of glacial periods, and mass extinction, etc. Activities of big earthquakes, volcanoes, or tsunami occurs more frequently probably every hundred of year.
  • The duration of human social activities continues only 40 years (25-65 ages), in which substantial impacts prevail あabout 20 years (35-55 ages). This is too short. This would be a major reason that influential people become conservative.
  • It is interesting that though black swan phenomenon is a small event, but typical example which affects human recognition of changing social and natural environment.
  • 何百万年単位の地質学的スケールでは遙かに激しい天変地異が起こる。大陸移動、造山運動、氷河期交代、大量絶滅など。大地震、火山、津波などはもっと頻繁におそらく百年単位で起こる。
  • 人間の社会的活動は高々40年(25-65歳)で、特に実質影響力は20年 (35-55歳)位であろう。これはあまりにも短期間である。これが影響力のある人々が保守的になる主因であろう。
  • 黒鳥現象は、小事件ではあっても、変化しつつある社会・自然環境に対する人間の認識に与える影響としては典型例ということで興味深い。

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