Nassim Nicholas Taleb

Quick Info

12 September 1960
Amioun, Lebanon

Nassim Taleb is a Lebanon-born American mathematician and statistician whose work concerns problems of randomness, probability and uncertainty.


Nassim Taleb's parents were Nagib Taleb, an oncologist and haematologist, and Minerva Ghosn, a anthropology researcher. Nagib and Minerva were Greek Orthodox Lebanese of the Greek Orthodox Church of Antioch but held French citizenship. Perhaps we should not use the label Lebanese since Nassim Taleb writes in [4]:-
It is remarkable how fast and how effectively you can construct a nationality with a flag, a few speeches, and a national anthem; to this day I avoid the label "Lebanese," preferring the less restrictive "Levantine" designation.
Both families had produced leading citizens in Lebanon. Minerva Ghosn's father, Fouad Nicolas Ghosn, and her grandfather, Nicolas Mikhael Ghosn, both held high ranking positions in the Lebanese government. Fouad Nicolas Ghosn (1911-1984) was elected MP representing Koura in 1953, 1960, 1964, 1968 and 1972. Elected Deputy Speaker of the House in 1963 and 1972, he was also Deputy Prime Minister and Minister of Justice of Lebanon in 1955, and Deputy Prime Minister and Minister of National Defence in 1973. Nicolas Mikhael Ghosn (1883-1955) represented Koura in 1913, was appointed by the French to the Administrative Council in 1920 and re-elected in 1925, 1929, 1934 and 1937. He was Deputy Prime Minister and Minister of Post, Telephone, Commerce and Industry in 1945. Nagib Taleb's father, Nassim Taleb, was a supreme court judge. This family background meant that the subject of this biography was born into a rich and high achieving family.

Nassim explained why his father was known as "Intelligent Student Student Intelligent" [6]:-
My father was known in Lebanon as the "Intelligent Student Student Intelligent", after a play on words as intelligent student (or scholar) meant "Taleb Nagib" and his name was Nagib Taleb, as the newspaper published his name for having the highest grade in the Lebanese baccalaureate, the high school exit exam.
Nagib Taleb had attended a Jesuit school which achieved exceptional results and it certainly did for Nagib since he achieved the highest grade in the Lebanese baccalaureate. Despite this achievement, Nagib did not like the education which produced results at the expense of students having any free time and being put though an extremely hard schedule. Nassim Taleb wrote [6]:-
... observing my father made me realise what being a valedictorian meant, what being an 'Intelligent Student' meant. First, he had a systematic way of viewing things, so I immediately realised, when I was about ten, that school grades weren't as good outside school as they carried some side effect with them. They had to correspond to a sacrifice, an intellectual sacrifice of sorts.
Taleb attended the Grand Lycée Franco-Libanais in Beirut. This school, founded in 1909, was considered the leading French Lycée in the Lebanon. Taleb always passed his examinations without much effort but began to develop a critical approach to the type of education he was receiving [6]:-
My parents had an account with the large bookstore in Beirut and I would pick up books and not pay for them, in what seemed to me unlimited amounts. There was such a difference between the shelves of the library and the narrow school material; so I realised that school was a plot designed to deprive people of erudition by squeezing their knowledge into a narrow set of authors. So, when in high school, around the age of thirteen, I started keeping a log of the number of hours I read, shooting for sixty hours a week, a practice I've kept for a long time.
In 1975 the Lebanese Civil War broke out which caused severe problems for the Grand Lycée Franco-Libanais was near the Green Line which separated the Muslim side of Beirut from the Christian side. The school buildings were badly damaged and access to the school was difficult. The Civil War had a disastrous effect on Taleb's family which lost much of its wealth and lost its political influence. When war broke out, he initially stayed in Beirut, then left, but after a while came back again. He recounted various events of his youth [6]:-
One summer I decided to read the twenty novels by Emile Zola in twenty days, one a day, and managed to do so at great expense. Perhaps joining a secret underground Trotskyist cell motivated me into Marxist studies, and picked up the most about Hegel indirectly ... my father gave me a complete break after I got published as a teenager in the local paper - play it safe at school and read on your own, have zero expectation from school. Later, after I was jailed for assaulting a policeman in a student riot, he acted scared of me and let me do whatever I wanted.
After he graduated from the Grand Lycée Franco-Libanais in Beirut, Taleb went to Paris for his university studies. He graduated with a Bachelor of Science degree with honours and a Master of Science degree. He said [6]:-
I studied the exact minimum necessary to pass any exam, overshooting accidentally once in a while, and only getting in trouble in few times by undershooting.
At the age of nineteen he went to the United States where he studied at the Wharton School at the University of Pennsylvania. This business school was founded by Joseph Wharton in 1881 and from 1921 offered an MBA (Master of Business Administration) programme. Great developments took place in the early 1970, before Taleb enrolled, including the opening of Vance Hall to house the Graduate Division, the creation of the Wharton Entrepreneurial Center and the MBA Program for Executives. Taleb studied at Wharton for his MBA degree but it was during his studies there that he became fascinated by probability arguments [6]:-
... at Wharton, I discovered that I wanted to specialise in a profession linked to probability and rare events, having a probability and randomness obsession forming in my mind. I also smelled some flaws with statistical stuff that the professor could not explain, brushing them away. At some point I realised that there was a fraud somewhere, that "six sigma" events (measures of rare events) were miscomputed and we had no basis for their computation but I could not articulate it clearly, and was getting humiliated by people who started smoking me with complicated mathematics. So I went to the bookstore and ordered (there was no web at the time) almost every book with "probability" or "stochastic" in its title. I started reading them in bed, jumping from one to the other when stuck with something I did not get immediately or felt ever so slightly bored. And I kept ordering those books. It was effortless. That was my best investment as it turned out to be the topic I know the best.
Taleb graduated from the Wharton School with an MBA in 1983. From December 1984 he became a Derivatives Trader [18]:-
... he held senior positions with major financial institutions: Credit Suisse First Boston, UBS, BNP-Paribas, Indosuez (now Calyon), Bankers Trust (now Deutsche Bank). He also worked as an independent pit trader and ran his own derivatives firm for 6 years.
On 30 January 1988, at St Anne's Episcopal Church in Atlanta, he married Cynthia Anne Shelton, the daughter of Joseph Marshall Shelton (1926-2003) of Atlanta. At the time of the marriage, Cynthia was studying for an MBA at New York University. She had graduated from the Woodward Academy in Atlanta and the University of Georgia before beginning the MBA course. Her father, a retired cinematographer, and her mother, Doris Haley Shelton, founded Shelton Productions, a film production company in Atlanta. Nassim and Cynthia Taleb had two children, Sarah Taleb and Alexander Taleb.

In the middle of the 1990s Taleb changed the direction that his career had been taking. The following comes partly from the Preface to [2] and partly from [6]:-
After closing about 200,000 option transactions (that is separate option tickets) over 12 years and studying about 70,000 risk management reports, I felt that I needed to sit down and reflect on the thousands of mishedges I had committed. ... I quietly deposited my necktie in the trash can at the corner of Forty-fifth Street and Park Avenue in New York. I decided to take a few years off and locked myself in the attic, trying to express what was coming out of my guts, trying to frame what I called "hidden nonlinearities" and their effects. ... I clambered up to my attic where, during 6 entire months, I spent 14 hours a day, 7 days a week, immersed in probability theory, numerical analysis, and mathematical statistics (at a Ph.D. level ). ... I fondly remember the two harsh New York winters in the near-complete silence of the attic, with the luminous effect of the sun shining on the snow warming up both the room and the project. I thought of nothing else for years. ... What I had wasn't quite an idea, rather, just a method, for the deeper central idea eluded me. But using this method, I produced close to a six-hundred-page-long discussion of managing nonlinear effects, with graphs and tables. ... "nonlinearity" means that the response is not a straight line. But I was going further and looking at the link with volatility, something that should be clear soon. And I went deep into the volatility of volatility, and such higher-order effects. The book that came out of this solitary investigation in the attic, finally called 'Dynamic Hedging', was about the "techniques to manage and handle complicated nonlinear derivative exposures."
This first major work by Taleb was Dynamic Hedging: Managing Vanilla and Exotic Options (1997).

He worked for a Ph.D. at the University of Paris (Dauphine) advised by Hélyette Geman. His thesis, The Microstructure of Dynamic Hedging, which focused on the mathematics of derivatives pricing, was examined by Hélyette Geman, Dilip Madan, Nicole El Karoui, Michel Lasry, and Marco Avellaneda. He was awarded his doctorate in 1998.

In 2001 Taleb published Fooled by Randomness: The Hidden Role of Chance in Life and in the Markets. Mark Rzepczynski, in the review [24] writes:-
Fooled by Randomness is clearly not a how-to-do-it book. Some, throwing up their hands after reading Taleb's musings, may say that nothing he offers is helpful because everything is subject to chance and cannot be proven. Others may feel uncomfortable with his intellectual wandering. Yet, those who have experienced the unforeseen or improbable in the last two decades will be impressed by the book's dictum that the words "it's not possible that ..." should not be uttered. Rare events are not only possible; they occur more often than we think. Crises are always occurring. Beware or be fooled.
Alex Kozinski, in the review [13] writes:-
Most of us would say you can't argue with success. If [an investment advisor] has managed to make profits over a sustained period, he must have a knack for anticipating the market, and its a pretty good bet he'll keep it up. This, hedge fund operator Taleb tells us, is an example of being fooled by randomness. The investment adviser's long string of successes may be only a streak of good luck that will end once you hand him your money. Counterintuitively, even a long series of wins can be the result of chance; it all depends on how many attempts you make. ... While it is important to remember, as Taleb shows in his charming and colourful book, that randomness can fool us, ignoring the most obvious inference from the available evidence can lead to errors as well. In the end, we cannot escape making judgments - and hoping for a little luck to help us along.
Taleb was appointed as a Fellow in the Mathematics Finance Program and an Adjunct Professor of Mathematics at Courant Institute of Mathematical Sciences of New York University in December 1999 and he continued in this post until December 2005. He served as Dean's Professor of Decision Sciences at the University of Massachusetts, Amherst, from January 2005 to January 2006. Throughout this time he continued working as a derivatives trader but, after spending 21 years doing this and, after closing 650,000 option transactions and examining 200,000 risk reports, Taleb changed his career in 2006 to become a scholar, mathematical researcher and philosophical essayist.

In 2007 Taleb published The Black Swan: The Impact of the Highly Improbable. This book has sold over 3 million copies, been translated into over 30 languages, and been named by The Sunday Times as one of the twelve most influential books since the Second World War.

You can read the beginning of the Prologue to the book at THIS LINK.

You can read some reviews of this 2007 edition and also of the second edition at THIS LINK.

In [30] Taleb summarises his theories as follows:-
I am exposing the fragility of knowledge about the tails of the distributions in domains where errors can be consequential. I discuss my operational reasons to select scalable laws, that is, "true fat tails" as default distributions and as tools to minimize exposure to such consequential errors. It is only in these cases of lessened tail dependence that statistics are safe - and that is where its strength lies. Finally I would like to thank the discussants and 'The American Statistician' for their open-mindedness and for giving me the opportunity to explain myself. This makes me extremely proud to be an applied statistician.
Taleb has written three further books: The Bed of Procrustes: Philosophical and Practical Aphorisms (2010), Antifragile: Things That Gain From Disorder (2012) and Skin in the Game: Hidden Asymmetries in Daily Life (2018). He has also written many papers and we list here some of those with a high mathematical/statistical content: (with Emanuel Derman) The illusions of dynamic replication (2005); Black swans and the domains of statistics (2007); Finiteness of variance is irrelevant in the practice of quantitative finance (2009); (with Charles S Tapiero) Risk externalities and too big to fail (2010); (with Raphael Douady) Mathematical definition, mapping, and detection of (anti)fragility (2013); (with Raphael Douady) On the super-additivity and estimation biases of quantile contributions (2015); (with Donald Geman and Hélyette Geman) Tail risk constraints and maximum entropy (2015); (with Pasquale Cirillo) On the statistical properties and tail risk of violent conflicts (2016); (with Pasquale Cirillo) Expected shortfall estimation for apparently infinite-mean models of operational risk (2016); Election predictions as martingales: an arbitrage approach (2018); and (with Andrea Fontanari and Pasquale Cirillo) Gini estimation under infinite variance (2018).

Taleb was a Visiting Research Professor at the London Business School, London from 2007 to 2009, then a Distinguished Research Scholar at the Said Business School BT Center, Oxford University from 2009 to 2013. He has been the Distinguished Professor of Risk Engineering at the Tandon School of Engineering, New York University since 2008.

Let us end with giving a quote from Taleb's interview [10]:-
I no longer care about the financial system. I gave them my roadmap. OK? Thanks, bye. I've no idea what's going on. I'm disconnected. I'm totally disengaged. People read 3 million copies of 'The Black Swan'. The bulk of them before the crisis. And people love it. They agree with it. They invite me to dinner. And they don't do anything about it. You have to pull back and let the system destroy itself, and then come back. That's Seneca's recommendation. He's the one who says that the sage should let the republic destroy itself. [It used to frustrate me.] Now it doesn't.

References (show)

  1. P Adams, Summary of Antifragile: Things that gain from disorder (BH via PublishDrive, 2018).
  2. N N Taleb, Dynamic Hedging: Managing Vanilla and Exotic Options (J Wiley, 1997).
  3. N N Taleb, Fooled by Randomness: The Hidden Role of Chance in Life and in the Markets (Random House, New York, 2001).
  4. N N Taleb, The Black Swan: The Impact of the Highly Improbable (Random House, New York, 2007).
  5. N N Taleb, The Bed of Procrustes: Philosophical and Practical Aphorisms (Random House, New York, 2010).
  6. N N Taleb, Antifragile: Things That Gain from Disorder (Random House, New York, 2012).
  7. N N Taleb, Skin in the Game: Hidden Asymmetries in Daily Life (Random House, New York, 2018).
  8. A Talk with Nassim Nicholas Taleb, The Edge (April 2004).
  9. A Brown, Strong Language on Black Swans, The American Statistician 61 (3) (2007), 195-197.
  10. C Cadwalladr, Interview: Nassim Taleb: my rules for life, The Guardian (24 November 2012).
  11. P Davidson, Black swans and Knight's epistemological uncertainty: are these concepts also underlying behavioral and post-Walrasian theory?, Journal of Post Keynesian Economics 32 (4) (2010), 567-570.
  12. R Garner and M Ash, Review: The Black Swan: The Impact of the Highly Improbable, by Nassim Nicholas Taleb, Science & Society 74 (2) (2010), 248-258.
  13. A Kozinski, Review: Fooled by Randomness: The Hidden Role of Chance in the Markets and in Life, by Nassim Nicholas Taleb, The Wilson Quarterly (1976-) 26 (2) (2002), 117-118.
  14. Learning to Expect the Unexpected, The New York Times (8 April 2004).
  15. R Lund, Review: The Black Swan: The Impact of the Highly Improbable, by Nassim Nicholas Taleb, The American Statistician 61 (3) (2007), 189-192.
  16. R H Murphy, The Unconstrained Vision of Nassim Taleb, The Independent Review 19 (3) (2015), 427-434.
  17. G L Musgrave, Review: The Black Swan: The Impact of the Highly Improbable, by Nassim Nicholas Taleb, Business Economics 44 (2) (2009), 123-125.
  18. Nassim Nicholas Taleb, Distinguished Professor of Risk Engineering, NTU Tandon School of Engineering.
  19. M Novarese, Review: The Black Swan: The Impact of the Highly Improbable, by Nassim Nicholas Taleb, History of Economic Ideas 15 (3) (2007), 188-191.
  20. Official Research Biography of Nassim Nicholas Taleb.
  21. B Pauker and Nassim Nicholas Taleb, Epiphanies: Nassim Nicholas Taleb, Foreign Policy 196 (2012), 29.
  22. C G Ranade, Review: The Bed of Procrustes: Philosophical and Practical Aphorisms, by Nassim Nicholas Taleb, Economic and Political Weekly 46 (24) (2011), 41-42.
  23. C G Ranade, of Bubbles and Black Swans, Economic and Political Weekly 45 (22) (2010), 4-5.
  24. M S Rzepczynski, Review: Fooled by Randomness: The Hidden Role of Chance in the Markets and in Life, by Nassim Nicholas Taleb, Financial Analysts Journal 58 (3) (2002), 102-103.
  25. P B Stares, Warning Signs: A Response to "The Calm Before the Storm", Foreign Affairs 94 (3) (2015), 160-162.
  26. J Suárez-Lledó, Review: The Black Swan: The Impact of the Highly Improbable (2nd ed.), by Nassim Nicholas Taleb, Academy of Management Perspectives 25 (2) (2011), 87-90.
  27. N N Taleb, The hard problem, The Edge (16 May 2010).
  28. N N Taleb, Real life is not a casino, The Edge (6 November 2008).
  29. N N Taleb, The fourth quadrant: A map of the limits of statistics, The Edge (14 September 2018).
  30. N N Taleb, Black Swans and the Domains of Statistics, The American Statistician 61 (3) (2007), 198-200.
  31. N N Taleb, Finiteness of Variance Is Irrelevant in the Practice of Quantitative Finance, Complexity 14 (3) (2008), 66-76.
  32. N N Taleb, Ten principles for a black-swan-robust world, The Edge (15 April 2018).
  33. A Terzi, Keynes's uncertainty is not about white or black swans, Journal of Post Keynesian Economics 32 (4) (2010), 559-565.
  34. K Vehkalahti, Review: The Black Swan: The Impact of the Highly Improbable, by Nassim Nicholas Taleb, International Statistical Review / Revue Internationale de Statistique 81 (2)(2013), 309-311.
  35. T Volery, Review: The Black Swan: The Impact of the Highly Improbable (2nd ed.), by Nassim Nicholas Taleb, Academy of Management Perspectives 22 (1) (2008), 69-70.
  36. P H Westfall and J M Hilbe, "The Black Swan": Praise and Criticism, The American Statistician 61 (3) (2007), 193-194.

Additional Resources (show)

Written by J J O'Connor and E F Robertson
Last Update January 2019