The Black Swan: The Impact of the Highly Improbable by Nassim Nicholas Taleb Summary and Reviews
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Book Reviews of The Black Swan: The Impact of the Highly Improbable
Book Review: Exposes the Flawed Assumptions of the Bell Curve Nudists, Those Who Always Decide by Using Normal Distribution Models
Summary: 5 Stars
Do you agree that being hit with a tsunami has a totally different effect from a normal high tide? If so, you'll be glad that Professor Taleb has decided to point out that all tsunamis (low probability, high impact events) need special attention, even if they occur infrequently. His advice: Minimize exposure to large potentially harmful events while taking maximum exposure to large potentially helpful events.
I was particularly thrilled to see that Professor Taleb points out the foolishness of economists in preparing theories without checking the data to see if the theories work in practice . . . the greater foolishness of the Nobel committee granting prizes for such work . . . and the greatest foolishness of relying on the advice of such economists.
Why all the fuss? Many phenomena display high predictability and the differences from the average usually don't make all that much difference to you and me (that quality is captured by a statistical display called a bell curve where most cases cluster near the average and vary symmetrically from the average). But in some cases, there are rare events that change the reality so strongly (like a tsunami can do on the negative side or a selection as an Oprah book of the month can do on the positive side) that it would be the height of foolishness to ignore the possibilities.
When it comes to assets, wealth, book sales, athlete pay, and lots of other places where there is lots of competition, there are geometric rewards for a few while the mass do poorly. These are long-tail events (the way statisticians talk about lots of variation from the norm). But almost all human decision making assumes that there is little variation from the norm.
The book concentrates on helping you understand why such a potentially harmful bias exists (brain structure plays a large role). We also assume a continuance of what's in front of us, even when there's obvious evidence to the contrary.
I was pleased to see these descriptions. I constantly run into the same problem with executives who are subject to stalled thinking and don't see opportunities right under their noses to accomplish 20 times as much. I liked Professor Taleb's points about overcoming our ignorance of antiknowledge . . . our tendency to discount what we haven't experienced or measured. I frequently see executives estimate that the best anyone will ever do at a level that someone already exceeded in 1880. In fact, in many important areas such as herbal health remedies, our actual knowledge is receding very rapidly, turning into antiknowledge.
To help break you free of how you think now, he uses a metaphor (a black swan -- is that really a swan?) and new terms (Mediocristan -- where the bell curve is the right way to think about things and Extremistan -- where powerful in effect black swans lurk). I found this tendency to be both helpful and not. It made it clearer to me what he was talking about the first time, and then made things seem muddier after that.
I suspect that for most people, the metaphor itself will be the biggest problem. Do you really care about black swans, per se? I don't. I think Professor Taleb would have done better to use two metaphors (one positive -- perhaps like formation and attraction of wealth to the Bill and Melinda Gates foundation and the foundation's effects on world health, and the other negative -- perhaps like a tsunami) than to focus on one that is mostly about definitions (black swan).
If you agree with Professor Taleb's main points, you will probably want to get lots of advice about how to do so. He's specific only in regard to two areas (wealth management and book publishing opportunities). That's a shame. Perhaps he will write a future book that will go more into solutions.
I was surprised to see that the book pretty much ignores the scenario work that many organizations use to identify the large impact, unlikely occurrence events and to devise strategies that work better under all possibilities. If that subject interests you, I suggest that you read books like The Art of the Long View and Inevitable Surprises by Peter Schwartz, Scenarios by Kees van der Heijdan, and The Irresistible Growth Enterprise by Carol Coles and me.
I was pleased to see that Professor Taleb also feels that many black swans can become "grey swans" by employing new prediction methods (although we cannot predict specifics, we can often predict up or down reasonably well in some situations). That has been my experience is seeing that Modern Portfolio Theory makes no sense in unsettled market conditions while more refined methods built stock-by-stock can be quite predictive over the short run in identifying over and under performers, even during unsettled market periods.
Check your models before you use them each day. Otherwise, you've just checked into work without your brains intact.
Keep your eyes and ears open whenever you are away from bell curves!
Book Review: EGOCENTRICITY
Summary: 1 Stars
This book would be excellent value for money -- IF, but only if one could buy just the Prologue. The rest of the tome is simply a repetition of the key thoughts of the Prologue. Just reading the Prologue would also avoid the painful overexposure to the autho'rs egocentric and self-aggrandizing character plus his bad jokes on the French nation which may result from an inferiority complex developed in his formerly French-civilized Lebanese home country.
Crispin Batten, Cape Town, South Africa
Book Review: The return of Nero Tulip
Summary: 5 Stars
2007 Random House, 396 pages (of which 305 pages for main body of book)
The Black Swan is a very unusual book. A couple of days after finishing it I still feel like I'm struggling to integrate its message with life. It reminds me a little of Richard Dawkins' Selfish Gene in that respect: its central thesis, which appears to be unassailably argued, indicates that the standard view of the world is wrong. In Dawkins' case, the primacy of the individual (as opposed to the gene) and in Taleb's case, the view that the world is essentially driven by normal, day-to-day events.
The subtitle of Taleb's book tells you what it is about: The Impact of the Highly Improbable. According to Taleb, high-impact rare events ('Black Swans') are not anything like as rare as we think they are and their effect is so disproportionately large that they effectively drive events in the world.
This may not sound all that provocative, but Taleb's argument is that virtually everybody's view of the world as essentially linear and step-by-step is just an illusion that protects us from understanding that our progress through life is much more random and fragile than we think.
Taleb's outstanding first book, Fooled by Randomness, is about the much greater role of luck in life than is commonly understood. The Black Swan develops this thesis further and shows that rare and unexpected events (what you might think of as a subdivision of luck) drive much of the results in the world.
Since reading Richard Koch's The 80/20 Principle eight or so years ago - after which I began to look at the world through the lens of unequal cause and effect - I have been coming gradually around to Taleb's views. Even so, The Black Swan is difficult to assimilate - and it must seem extremely odd (and itself most improbable) to those who have not had some preparation.
One can see this difficulty in the absolute refusal of modern academic finance to give up theories of how the world works (the bell curve or pattern of 'normal' distribution) that allow them to use complicated mathematics and which are just plain wrong. Taleb thought the Long Term Capital Management debacle in 1998 - in which various Nobel-winning economists proved their (Nobel-winning) ideas did not apply in the real world - would be the end of these dangerously wrong beliefs.
However, it was Taleb who was wrong about that: a whole gang of academics who have invested a good chunk of their lives in an idea that turns out to be worthless (actually significantly negative) won't give it up easily (and perhaps not until they are all dead). The sub-prime mess, with accompanying cries of surprise and of '25-standard deviation events' from various hog-greedy financiers and hedge fund managers, shows the continued prevalence of these appalling ideas.
After the success of Fooled by Randomness, it would appear that Taleb had more freedom to write (and be published) however he wanted. It makes The Black Swan more idiosyncratic and aggressive than Fooled by Randomness. I imagine this will act as a polariser and some people who would otherwise appreciate the content may not like the delivery. Personally, though, I loved it.
As someone who has tried working in various jobs in the City of London (the UK equivalent of Wall Street) I feel in some ways that Taleb is a kindred spirit: I can't stand arrogant, ignorant 'empty suits' either. I thought his "Get Another Job" section (p. 163) was perfect:
"There are those people who produce forecasts uncritically. When asked why they forecast, they answer, "Well, that's what we're paid to do here."
My suggestion: get another job.
This suggestion is not too demanding: unless you are a slave, I assume you have some amount of control over your job selection. Otherwise this becomes a problem of ethics, and a grave one at that. People who are trapped in their jobs who forecast simply because "that's my job," knowing pretty well that their forecast is ineffectual, are not what I would call ethical. What they do is no different from repeating lies simply because "it's my job.""
Taleb's very severe and aggressive criticism of risk measurement techniques in modern finance could be interpreted as an intemperate rant. I don't subscribe to this view and suspect Taleb chose this approach deliberately in order to make it clear that the prevalent financial risk management techniques and his ideas cannot in any way coexist: they are absolutely and totally mutually exclusive. (Taleb mentions that after finding it impossible to refute his ideas some people then try to combine them with their old ways of operating.)
I also liked the way Taleb approached and structured his book: he uses stories to get ideas across (as with Nero Tulip in Fooled by Randomness) and has separated his book into sections that allow one to understand his ideas with or without the scientific underlay (I think this is a great idea).
Some people (whether wilfully or not) confused the central theme of Fooled by Randomness, that much of life is driven by luck, with the superficially similar but totally different 'all of life is driven by luck'. In a similar way, I believe some people think that Taleb's message in The Black Swan is unremittingly negative: that we are all permanently exposed to large unexpected events that can wreck all our plans in an instant, and which we can do nothing about.
Taleb's point is rather that most specific forecasting is pointless, as large, rare and unexpected events (which by definition could not have been included in the forecast) will render the forecast useless. However, as Black Swans can be both negative and positive, we can try to structure our lives in order to minimise the effect of the negative Black Swans and maximise the impact of the positive ones.
I think this is excellent advice on how to live one's life and seems to be equivalent, for example, to the focus on downside protection (rather than upside potential) that has led to the success of the 'value' approach to investing. Highly recommended.
Book Review: Beware this outlier
Summary: 5 Stars
Taleb's life story is so improbable, his practical adherence to Popperian philosophy so unfashionable, and his style so quirky, that most people will ignore his ranting about fatal bias as the squeaking of a hobby horse ridden by a crank. He is probably better described as a contrarian among contrarians. And boy does he know it.
Still, we should be grateful that Taleb's taste for fame exceeds his avidity. For in exposing the inadequacy of how we model the non-material world, Taleb risks the erosion of the causal blindness arbitrage opportunities from which he claims to have made a living.
The good news is that people are just as stubborn when they are wrong, so there is plenty of time to exploit to your advantage the insights Taleb is offering you here - although an uncharitable reading is that he is simply arguing for a wider use of insurance.
Taleb's Popperian probabilism will eventually enter the mainstream, whereupon it will all seem rather obvious, and you (and he) will be assailed by bores who claim to have been Talebistes all along, just like the traders and pundits Taleb lampoons for triumphantly predicting the past.
If you are content to live life inside one standard deviation, you therefore don't need to read this book - just wait for all this to become 'best practice'.
Incidentally, there is a lot of overlap between this and Fooled by Randomness - you don't really need both, and the latter is more readable.
Book Review: The impact of The Impact of the Highly Improbable
Summary: 4 Stars
An excellent book by NNT, which would have undoubtedly gained a five star rating had it not been sandwiched between my reading of The God Delusion (Richard Dawkins) and When a Crocodile Eats the Sun (Peter Godwin); which were both immense. Taleb articulately, and simply, shows the failings of the philosopher and the forecaster in a book that holds the reader throughout. Often, without story-telling or action, a book can be a slow read, however by using strong anology Taleb conveys his message superbly. Unlike The God Delusion, I began this book uncertain of what I would gain from it, and I can say that The Black Swan has given me a very different view on my life and work.