Here's probably one of the toughest review I ever had to write and I am not sure it is a good one, even if the topic I am addressing is great and important. But it's been a challenge to summarize what I learnt: Nicholas Nassim Taleb gives in this follow-up to the Black Swan a very interesting analysis of how the world can be less exposed to Black Swans, not by becoming more robust only, but by becoming antifragile, i.e. by benefiting from random events. His views include tensions between the individual and the groups, how distributed systems are more robust than centralized ones, how small unites are less fragile than big ones. This does not mean Taleb is against orgamizations, governments or laws as too little intervention induces totally messy situations. It is about putting the cursor at the right level. Switzerland represents for Taleb a good illustration of good state organizations with little central government, a lot of local responsibility. He has similar analogies for the work place, where he explains that an independent worker, who knows well his market, is less fragile to crises than big corporations and their employees. One way to make systems less fragile is to put some noise, some randomness which will stabilize them. This is well-known in science and also in social science. Just remember Athens was randomly nominating some of its leaders to avoid excess!
Now let me quote the author. These are notes only but for serious reviews, visit the author's website, fooledbyrandomness. First Taleb is, as usual, unfair but maybe less than in the Black Swan. Here is an example: "Academics (particularly in social science) seem to distrust each other, [...] not to mention a level of envy I have almost never seen in business... My experience is that money and transactions purify relations; ideas and abstract matters like "recognition" and "credit" warp them, creating an atmosphere of perpetual rivalry. I grew to find people greedy for credentials nauseating, repulsive, and untrustworthy." [Page 17] Taleb is right about envy and rivalry but wrong in saying it is worse in academia; I think it is universal! In politics for example. But when money is available, maybe rivalry counts less than where there is little.
Now a topic close to my activity: "This message from the ancients is vastly deeper than it seems. It contradicts modern methods and ideas of innovation and progress on many levels, as we tend to think that innovation comes from bureaucratic funding, through central planning, or by putting people through a Harvard Business School class by one Highly Decorated Professor of Innovation and Entrepreneurship (who never innovated anything) or hiring a consultant (who never innovated anything). This is a fallacy - note for now the disproportionate contribution of uneducated technicians and entrepreneurs to various technological leaps, from the Industrial Revolution to the emergence of Silicon Valley, and you will see what I mean." [Page 42] [Extreme and unfair again, even if not fully wrong!]
"The antifragility of some comes necessarily at the expense of the fragility of others. In a system, the sacrifices of some units - fragile units, that is, or people - are often necessary for the well-being of other units or the whole. The fragility of every start-up is necessary for the economy to be antifragile, and that's what makes, among other things, entrepreneurship work: the fragility of the individual entrepreneurs and their necessarily high failure rate". [Page 65] What surprised me later is that Taleb shows that this is true of restaurants (not many succeed) as much as of high-tech start-ups. So it is not only about the uncertainty of new markets, but about uncertainty above all.
Mathematics of convexity
I have to admit Taleb is not easy to read. Not because it is complex (sometimes his ideas are pure common sense), but because it is dense with different even if consistent ideas. The book is divided in 25 chapters, but also in 7 books. In fact, Taleb insists on it, he might have written 7 different books! Even his mathematics is simple. His definition of convexity is a little strange though I found it interested (I teach convex optimization, and you might not know, it was the topic of my PhD!).
Jensen inequality is interesting [Pages 342, 227 - Jensen was an amateur mathematician!]- the convex transformation of a mean is less or equal than the mean after convex transformation. Again individual (concave, we die) vs. collective (convex, antifragile, benefits from individual failures). So risk taking is good for collectivity if with insurance mechanisms. Risk taking + insurance vs. speculation with no value added. An example of a short and deep idea: "Decision making is based on payoffs, not knowledge". [Page 337]
"Simply, small probabilities are convex to errors of computation. One needs a parameter, called standard deviation, but uncertainty about standard deviation has the effect of making the small probabilities rise. Smaller and smaller probabilities require more precision in computation. In fact small probabilities are incomputable, even if one has the right model - which we of course don't." [Taleb fails to mention Poincare yet he quoted him in the Black Swan, but whatever.]
A visible tension between individual and collective interests
Quotes again: "What the economy, as a collective, wants [business school graduates] to do is not to survive, rather to take a lot, a lot of imprudent risks themselves and be blinded by the odds. Their respective industries improve from failure to failure. Natural and nature-like systems want some overconfidence on the part of the individual economic agents, i.e., the overestimation of their chances of success and underestimation of the risks of failure in their business, provided their failure does not impact others. In other words, they want local, but not global overconfidence". [...] In other words, some class of rash, even suicidal, risk taking is healthy for the economy - under the conditions that not all people take the same risks and that these risks remain small and localized. Now, by disrupting the model, as we will see, with bailouts, governments typically favor a certain class of firms that are large enough to require being saved in order to avoid contagion to other businesses. This is the opposite of healthy risk taking; it is transferring fragility from the collective to the unfit. [...] Nietzsche's famous expression "what does not kill me makes me stronger" can be easily implemented as meaning Mithridatization or Hormesis but it may also mean "what did not kill me did not make me stronger, but it spared me because I am stronger than others; but it killed others and the average population is now stronger because the weak are gone". [...] This visible tension between individual and collective interests is new in history. [...] Some of the ideas about fitness and selection are not very comfortable to this author, which makes the writing of some sections rather painful - I detest the ruthlessness of selection, the inexorable disloyalty of Mother Nature. I detest the notion of improvement thanks to harm to others. As a humanist, I stand against the antifragility of systems at the expense of individuals, for if you follow the reasoning, this makes us humans individually irrelevant. " [Pages 75-77]
A National Entrepreneur Day
"Compare the entrepreneurs to the bean-counting managers of companies who climb the ladder of hierarchy with hardly ever any real downside. Their cohort is rarely at risk. My dream - the solution - is that we would have a National Entrepreneur Day, with the following message: Most of you will fail, disrespected, impoverished, but we are grateful for the risks you are taking and the sacrifices you are making for the sake of the economic growth of the planet and pulling others out of poverty. You are the source of our antifragility. Our nation thanks you." [Page 80]
Local distributed systems, randomness and modernity
"You never have a restaurant crisis. Why? Because it is composed of a lot of independent and competing small units that do not individually threaten the system and make it jump from one state to another. Randomness is distributed rather than concentrated." [Page 98]
"Adding a certain number of randomly selected politicians to the process can improve the functioning of the parliamentary system." [Page 104]
"Modernity is the humans' large-scale domination of the environment, the systematic smoothing of the world's jaggedness, and the stifling of volatility and stressors. We are going into a phase of modernity marked by the lobbyist, the very, very limited liability corporation, the MBA, sucker problems, secularization, the tax man, fear of the boss..." [Page 108]
"Iatrogenics means literally "caused by the healer". Medical error still currently kills between three times (as accepted by doctors) and ten times as many people as car accidents in the United States, it is generally accepted that harm from doctors - not including risks from hospitals germs - accounts for more deaths than any single cancer. Iatrogenics is compounded by the "agency problem" which emerges when one party (the agent) has personal interested that are divorced from those of the one using his services (the principal). An agency problem is present with the stockbroker and medical doctor whose ultimate interest is their own checking account, not your financial and medical health." [Pages 111-112]
Theories and intervention.
"Theories are super-fragile outside physics. The very designation "theory" is even upsetting. In social science, we should call these constructs "chimeras" rather than theories. [Now you understand why Taleb has many enemies.] A main source of the economic crisis started in 2007 in the Iatrogenics of the attempt by [...] Alan Greenspan to iron out the "boom-bust" cycle which caused risks to go hide under the carpet. The most depressing part of the Greenspan story is that the fellow was a libertarian and seemingly convinced of the idea of leaving systems to their own devices; people can fool themselves endlessly. [...] The argument is not against the notion of intervention; in fact I showed above that I am equally worried about under-intervention when it is truly necessary. [...] We have a tendency to underestimate the role of randomness in human affairs. We need to avoid being blinded to the natural antifragility of systems, their ability to take care of themselves and fight our tendency to harm and fragilize them by not giving them a chance to do so. [...] Alas, it has been hard for me to fit these ideas about fragility within the current US political discourse. The democratic side of the US spectrum favors hyper-intervention, unconditional regulation and large government, while the Republican side loves large corporations, unconditional deregulation and militarism, both are the same to me here. Let me simplify my take on intervention. To me it is mostly about having a systematic protocol to determine when to intervene and when to leave systems alone. And we may need to intervene to control the iatrogenics of modernity - particularly the large-scale harm to the environment and the concentration of potential (though not yet manifested) damage, the kind of thing we only notice when it is too late. The ideas advanced here are not political, but risk-management based. I do not have a political affiliation or allegiance to a specific party; rather, I am introducing the idea of harm and fragility into the vocabulary so we can formulate appropriate policies to ensure we don't end up blowing up the planet and ourselves." [Pages 116-118]
"To conclude, the best way to mitigate interventionism is to ration the supply of information. The more data you get, the less you know." [Page 128]
"Political and economic "tail" events are unpredictable and their probabilities are not scientifically measurable." [Page 133]
The barbell strategy and optionality
"The Barbell strategy is a way to achieve anti-fragility, by decreasing downside rather than increasing upside, by lowering exposure to negative Black Swans. So just as Stoicism is the domestication, not the elimination, of emotions, so is the barbell a domestication, not the elimination, of uncertainty." [Page 159] "It is a combination of two extremes, one safe and one speculative, deemed more robust than a monomodal strategy. In biological systems, the equivalent of marrying an accountant and having an occasional fling with a rock star; for a writer, getting a stable sinecure and writing without the pressures of the market. Even trial and error are a form of barbell." [Glossary page 428]
"The strength of the computer entrepreneur Steve Jobs was precisely in distrusting market research and focus groups - those based on asking people what they want - and following his own imagination, his modus was that people don't know what they want until you provide them with it." [Page 171]
"America's asset is simply risk taking and the use of optionality, the remarkable ability to engage in rational forms of trial and error, with no comparative shame in failing, starting again and repeating failure. In modern Japan, by contrast, shame comes, with failure, which causes people to hide risks under the rug, financial or nuclear."
"Nature does a California-style "fail early" - it has an option and uses it. Nature understands optionality effects better than humans. [...] The idea is voiced by Steve Jobs in a famous speech: "Stay hungry, stay foolish." He probably meant "Be crazy but retain the rationality of choosing the upper bound when you see it." Any trial and error can be seen as the expression of an option, so long as one is capable of identifying a favorable result and exploiting it." [Page 181]
"Option is a substitute for knowledge- actually I don't understand what sterile knowledge is, since it is necessarily vague and sterile. So I make the bold speculation that many things we think are derived by skill come largely from options, but well-used options, much like Thales's situation [who had an option with olive presses - pages 173-174] rather than from what we claim to be understanding." [Page 186]
Taleb is skeptical with experts, with anyone believing in a linear model academia -> applied science ->practice ("lecturing birds how to fly"); he believes in tinkering, heuristics, apprenticeship, and makes again many enemies for free! He claims the jet engine, financial derivatives, architecture, medicine were first developed by practitioners and then theorized by scientists, not invented or discovered by them.
Tinkering vs. research
"There has to be a form of funding that works. By some vicious turn of events, governments have gotten huge payoffs from research, but not as intended - just consider the Internet. It is just that functionaries are too teleological in the way they look for things and so are large corporations. Most large companies, such as Big Pharma, are their own enemies. Consider blue sky research, whereby grants and funding are given to people, not projects, and spread in small amounts across many researchers. It's been reported that in California, venture capitalists tend to back entrepreneurs, not ideas. Decisions are largely a matter of opinion, strengthened with who you know. Why? Because innovations drift, and one needs flâneur-like abilities to keep capturing the opportunities that arise. The significant venture capital decisions were made without real business plans. So if there was any analysis, it had to be of a backup, confirmatory nature. Visibly the money should go to the tinkerers, the aggressive tinkerers who you trust will milk the option." [Page 229]
"Despite the commercial success of several companies and the stunning growth in revenues for the industry as a whole, most biotechnology firms earn no profit." [Page 237] [Optionality again]
"(i) Look for optionality; in fact, rank things according to optionality, (ii) preferably with open-ended, not closed-ended, payoffs; (iii) do not invest in business plans but in people, so look for someone capable of changing six or seven times over his career, or more (an idea that is part of the modus operandi of the venture capitalist Marc Andreessen); one gets immunity from the backfit narratives of the business plan by investing in people. Make sure you are barbelled, whatever that means in your business." [Page 238]
"I did here just debunk the lecturing-Birds-How-to-Fly epiphenomenon and the "linear model", suing simple mathematical properties of optionality. There Is no empirical evidence to support the statement that organized research in the sense it is currently marketed leads to great things promised by universities. [Cf also Peter Thiel lamentations about the promise of technologies] Education is an institution that has been growing without external stressors; eventually the thing will collapse." [A conclusion to book IV, page 261]
Why is fragility non linear?
"For the fragile, the cumulative effect of small shocks is smaller than the single effect of an equivalent single large shock. For the antifragile, shocks bring more benefits (equivalently, less harm) as their intensity increases (up to a point)."
Via negativa
"We may not need a name for or even an ability to express anything. We may just say something about what it is not. Michelangelo was asked by the pope about the secret of his genius, particularly how he carved the statue of David. His answer was: It's simple, I just remove everything that is not David." [Page 302-304]
[...] "Charlatans are recognizable in that they will give you positive advice. Yet in practice, it is the negative that's used by the pros. One cannot really tell if a successful person has skills, or if a person with skills will succeed - but we can pretty much predict the negative, that a person totally devoid of skills will eventually fail."
[...] "The greatest - most robust - contribution to knowledge consist in removing what we think is wrong. We know a lot more what is wrong than what is right. Negative knowledge is more robust to error than positive knowledge. [...] Since one small observation can disprove a statement, while millions can hardly confirm it [The Black Swan!], disconfirmation is more rigorous than confirmation. [...] Let us say that, in general, failure (and disconfirmation) are more informative than success and confirmation."
[Funnily, I remember the main critics against my book were the lack of [positive] proposal in the end. I should have said there we many about what not to do!]
"Finally, consider this modernized version in a saying from Steve Jobs: "People think focus means saying yes to the thing you've got to focus on. But that's not what it means at all. It means saying no to the hundred other good ideas that there are. You have to pick carefully. I'm actually as proud of the things we haven't done as the things I have done. Innovation is saying no to 1,000 things." [Page 302-304]
Less is more
"Simpler methods for forecasting and inference can work much, much better than complicated ones. "Fast and frugal" heuristics make good decisions despite limited time. First extreme effects: there are domains in which the rare event (good or bad) plays a disproportionate share and we tend to be blind to it. Just worry about Black Swan exposures and life is easy. There may not be an easily identifiable cause for a large share of the problems, but often there is an easy solution, sometimes with the naked eye rather than the use of the complicated analyses. Yet people want more data to solve problems." [Page 305-306]
"The way to predict rigorously is to take away from the future, reduce from it things that do not belong to the coming times. What is fragile will eventually break, and luckily we can easily tell what is fragile. Positive Black Swans are more unpredictable than negative ones. Now I insist on the via negativa method of prophecy as being the only valid one." [Page 310]
"For the perishable, every additional day in the life translates into a shorter additional life expectancy. For the non perishable, every additional day may imply a longer life expectancy. On general, the older the technology, the longer it is expected to last. I am not saying that all technologies do not age, only that those technologies that were prone to aging are already dead." [Page 319]
"How can we teach children skills for the twenty-first century, since we do not know which skills will be needed? Effectively my answer would make them read the classics. The future is in the past. Actually there is an Arabic proverb to that effect: he who does not have a past has no future." [Page 320]
[As can be read later in the book Taleb does not like the Bay Area culture. And it is no coincidence, it is a region with nearly no past, nearly no history, but it certainly help it create Silicon Valley innovations...]
"If you have an old oil painting and a flat screen television, you will never mind changing the television, not the painting. Same with an old fountain pen and the latest Apple computer; [Taleb is really cautious with modernity and innovation, even if a user of it. With architecture, he has similar concerns. Again he prefers tradition to aggressive modernity. Same with the metric system vs. old methods] Top-down is usually irreversible, so mistakes tend to stick, whereas bottom-up is gradual and incremental, with creation and destruction along the way, thought presumably with a positive slope." [Pages 323-24]
"So we can apply criteria of fragility and robustness to the handling of information - the fragile in that context is, like technology, what does not stand the test of time. [...] Books that have been around for ten years will be around for ten more; books that have been around for two millennia should be around for quite a bit of time. [...] The problem in deciding whether a scientific result or a new "innovation" is a breakthrough, that is, the opposite of noise, is that one needs to see all aspects of the idea - and there is always some opacity that time, and only time, can dissipate." [Page 329]
"Now, what is fragile? The large, optimized, overreliance on technology, overreliance on the so-called scientific method instead of age-tested heuristics."
"By issuing warnings based on vulnerability - that is, substractive prophecy - we are closer to the original role of the prophet: to warn, not necessarily to predict, and to predict calamities if people don't listen."
Ethics
"Under opacity and complexity, people can hide risks and hurt others. Skin in the game is the only true mitigator of fragility. We have developed a fondness for neomanic complication over archaic simplicity. [...] The worst problem of modernity lies in the malignant transfer of fragility and antifragility from one party to the other, with one getting the benefits, the other one (unwittingly) getting the harm, with such transfer facilitated by the growing wedge between the ethical and the legal. Modernity hides it especially well. It is of course an agency problem." [Page 373]
[You can/should have a look at table 7, page 377]
"In traditional societies, a person is only respectable and as worthy as the downside he (or, more, a lot more, than expected, she) is willing to face for the sake of others." [Page 376]
"I want predictors to have visible scars on their body from prediction errors, not distribute these errors to society." [Page 386]
[Don Quixote was already the sign of the end of the heroism, of the ethical behavior. Taleb's models are Malraux and Ralph Nader - "the man is a secular saint" [Page 394]. His enemies Thomas Friedman, Rubin and Stieglitz]
[Is "skin in the game" the only way? The only solution? What about transparency?]
About Science
"Science must not be a competition; it must not have rankings - we can see how such a system will end up blowing up. Knowledge must not have an agency problem. One doctoral student once came to tell me that he believed in my ideas of fat tails and my skepticism of current methods of risk management, but that it would not help him get an academic job. "It's what everybody teaches and uses in papers" he said. Another student explained that he wanted a job at a good university, so he could make money testifying as an expert witness - they would not buy my idea on robust risk management because "everyone uses these textbooks". [Page 419] [So true!]
Conclusion
"All I want is to remove the optionality, reduce the antifragility of some at the expense of others. It is simple via negativa. [...] The golden rule: "Don't do unto others what you don't want them to do to you". [...] Everything gains or loses from volatility. Fragility is what loses from volatility or uncertainty. [...] Time is volatility. Education in the sense of the formation of the character, personality, and acquisition of true knowledge, likes disorder; label-driven education and educators abhor disorder. Innovation is precisely something that grains from uncertainty." [Pages 420-22]
"It so happens that everything nonlinear is convex, concave or both. [...] We can build Black-Swan-protected systems thanks to detection of concavity, [...] and with a mechanism called convex transformation, the fancier name for the barbell. [...] Distributed randomness (as opposed to the concentrated type) is a necessity."
[General comments]
Taleb sometimes gives the feeling of contradictions: marketing is bad, but Steve Jobs is great; barbell strategy and optionality is great, but isn't it about risks and downsides transferred to others [Isn't Thales a pure speculator?], cigarettes are bad but traditions are good.
Also this love of tradition makes people with more background at ease to take risks with barbell strategy; but what about the poor with nothing to lose? Benefits might statistically go to those who already have... [It reminds the story told by J.-B. Doumeng: It is a millionaire who recounts his difficult beginnings: "I bought an apple 50 cents, I polished it to shine and I sold it for one franc. With this, I bought two apples 50cts, I carefully polished and I sold them 2 Fr after a moment, I could buy a cart to sell my apples and then I made a big inheritance..."]
You now know why it has been a challenge. A very strange, dense, fascinating book, but if you like these concepts, you must read Antifragile. In fact you must read the Black Swan first, if you have not and if you like it, I am sure you will read Antifragile.
Antifragile: Things That Gain from Disorder
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Top reviews from the United States
Herve Lebret5.0 out of 5 stars
After the Black Swan, Taleb strikes again with Antifragile
Reviewed in the United States on January 22, 2013
John Walker5.0 out of 5 stars
Superb exploration of systems which benefit from randomness and uncertainty
Reviewed in the United States on December 16, 2019
This book is volume three in the author's
Incerto
series, following
Fooled by Randomness
and
The Black Swan
. It continues to explore the themes of randomness, risk, and the design of systems: physical, economic, financial, and social, which perform well in the face of uncertainty and infrequent events with large consequences. He begins by posing the deceptively simple question, “What is the antonym of ‘fragile’?”
After thinking for a few moments, most people will answer with “robust” or one of its synonyms such as “sturdy”, “tough”, or “rugged”. But think about it a bit more: does a robust object or system actually behave in the opposite way to a fragile one? Consider a teacup made of fine china. It is fragile—if subjected to more than a very limited amount of force or acceleration, it will smash into bits. It is fragile because application of such an external stimulus, for example by dropping it on the floor, will dramatically degrade its value for the purposes for which it was created (you can't drink tea from a handful of sherds, and they don't look good sitting on the shelf). Now consider a teacup made of stainless steel. It is far more robust: you can drop it from ten kilometres onto a concrete slab and, while it may be slightly dented, it will still work fine and look OK, maybe even acquiring a little character from the adventure. But is this really the opposite of fragility? The china teacup was degraded by the impact, while the stainless steel one was not. But are there objects and systems which improve as a result of random events: uncertainty, risk, stressors, volatility, adventure, and the slings and arrows of existence in the real world? Such a system would not be robust, but would be genuinely “anti-fragile” (which I will subsequently write without the hyphen, as does the author): it welcomes these perturbations, and may even require them in order to function well or at all.
Antifragility seems an odd concept at first. Our experience is that unexpected events usually make things worse, and that the inexorable increase in entropy causes things to degrade with time: plants and animals age and eventually die; machines wear out and break; cultures and societies become decadent, corrupt, and eventually collapse. And yet if you look at nature, antifragility is everywhere—it is the mechanism which drives biological evolution, technological progress, the unreasonable effectiveness of free market systems in efficiently meeting the needs of their participants, and just about everything else that changes over time, from trends in art, literature, and music, to political systems, and human cultures. In fact, antifragility is a property of most natural, organic systems, while fragility (or at best, some degree of robustness) tends to characterise those which were designed from the top down by humans. And one of the paradoxical characteristics of antifragile systems is that they tend to be made up of fragile components.
How does this work? We'll get to physical systems and finance in a while, but let's start out with restaurants. Any reasonably large city in the developed world will have a wide variety of restaurants serving food from numerous cultures, at different price points, and with ambience catering to the preferences of their individual clientèles. The restaurant business is notoriously fragile: the culinary preferences of people are fickle and unpredictable, and restaurants who are behind the times frequently go under. And yet, among the population of restaurants in a given area at a given time, customers can usually find what they're looking for. The restaurant population or industry is antifragile, even though it is composed of fragile individual restaurants which come and go with the whims of diners, which will be catered to by one or more among the current, but ever-changing population of restaurants.
Now, suppose instead that some Food Commissar in the All-Union Ministry of Nutrition carefully studied the preferences of people and established a highly-optimised and uniform menu for the monopoly State Feeding Centres, then set up a central purchasing, processing, and distribution infrastructure to optimise the efficient delivery of these items to patrons. This system would be highly fragile, since while it would deliver food, there would no feedback based upon customer preferences, and no competition to respond to shifts in taste. The result would be a mediocre product which, over time, was less and less aligned with what people wanted, and hence would have a declining number of customers. The messy and chaotic market of independent restaurants, constantly popping into existence and disappearing like virtual particles, exploring the culinary state space almost at random, does, at any given moment, satisfy the needs of its customers, and it responds to unexpected changes by adapting to them: it is antifragile.
Now let's consider an example from metallurgy. If you pour molten metal from a furnace into a cold mould, its molecules, which were originally jostling around at random at the high temperature of the liquid metal, will rapidly freeze into a structure with small crystals randomly oriented. The solidified metal will contain dislocations wherever two crystals meet, with each forming a weak spot where the metal can potentially fracture under stress. The metal is hard, but brittle: if you try to bend it, it's likely to snap. It is fragile.
To render it more flexible, it can be subjected to the process of annealing, where it is heated to a high temperature (but below melting), which allows the molecules to migrate within the bulk of the material. Existing grains will tend to grow, align, and merge, resulting in a ductile, workable metal. But critically, once heated, the metal must be cooled on a schedule which provides sufficient randomness (molecular motion from heat) to allow the process of alignment to continue, but not to disrupt already-aligned crystals.
When you observe a system which adapts and prospers in the face of unpredictable changes, it will almost always do so because it is antifragile. This is a large part of how nature works: evolution isn't able to predict the future and it doesn't even try. Instead, it performs a massively parallel, planetary-scale search, where organisms, species, and entire categories of life appear and disappear continuously, but with the ecosystem as a whole constantly adapting itself to whatever inputs may perturb it, be they a wholesale change in the composition of the atmosphere (the oxygen catastrophe at the beginning of the Proterozoic eon around 2.45 billion years ago), asteroid and comet impacts, and ice ages.
Most human-designed systems, whether machines, buildings, political institutions, or financial instruments, are the antithesis of those found in nature. They tend to be highly-optimised to accomplish their goals with the minimum resources, and to be sufficiently robust to cope with any stresses they may be expected to encounter over their design life. These systems are not antifragile: while they may be designed not to break in the face of unexpected events, they will, at best, survive, but not, like nature, often benefit from them.
The devil's in the details, and if you reread the last paragraph carefully, you may be able to see the horns and pointed tail peeking out from behind the phrase “be expected to”. The problem with the future is that it is full of all kinds of events, some of which are un-expected, and whose consequences cannot be calculated in advance and aren't known until they happen. Further, there's usually no way to estimate their probability. It doesn't even make any sense to talk about the probability of something you haven't imagined could happen. And yet such things happen all the time.
Today, we are plagued, in many parts of society, with “experts” the author dubs fragilistas. Often equipped with impeccable academic credentials and with powerful mathematical methods at their fingertips, afflicted by the “Soviet-Harvard delusion” (overestimating the scope of scientific knowledge and the applicability of their modelling tools to the real world), they are blind to the unknown and unpredictable, and they design and build systems which are highly fragile in the face of such events. A characteristic of fragilista-designed systems is that they produce small, visible, and apparently predictable benefits, while incurring invisible risks which may be catastrophic and occur at any time.
Let's consider an example from finance. Suppose you're a conservative investor interested in generating income from your lifetime's savings, while preserving capital to pass on to your children. You might choose to invest, say, in a diversified portfolio of stocks of long-established companies in stable industries which have paid dividends for 50 years or more, never skipping or reducing a dividend payment. Since you've split your investment across multiple companies, industry sectors, and geographical regions, your risk from an event affecting one of them is reduced. For years, this strategy produces a reliable and slowly growing income stream, while appreciation of the stock portfolio (albeit less than high flyers and growth stocks, which have greater risk and pay small dividends or none at all) keeps you ahead of inflation. You sleep well at night.
Then 2008 rolls around. You didn't do anything wrong. The companies in which you invested didn't do anything wrong. But the fragilistas had been quietly building enormous cross-coupled risk into the foundations of the financial system (while pocketing huge salaries and bonuses, while bearing none of the risk themselves), and when it all blows up, in one sickening swoon, you find the value of your portfolio has been cut by 50%. In a couple of months, you have lost half of what you worked for all of your life. Your “safe, conservative, and boring” stock portfolio happened to be correlated with all of the other assets, and when the foundation of the system started to crumble, suffered along with them. The black swan landed on your placid little pond.
What would an antifragile investment portfolio look like, and how would it behave in such circumstances? First, let's briefly consider a financial option. An option is a financial derivative contract which gives the purchaser the right, but not the obligation, to buy (“call option”) or sell (”put option”) an underlying security (stock, bond, market index, etc.) at a specified price, called the “strike price” (or just “strike”). If the a call option has a strike above, or a put option a strike below, the current price of the security, it is called “out of the money”, otherwise it is “in the money”. The option has an expiration date, after which, if not “exercised” (the buyer asserts his right to buy or sell), the contract expires and the option becomes worthless.
Let's consider a simple case. Suppose Consolidated Engine Sludge (SLUJ) is trading for US$10 per share on June 1, and I buy a call option to buy 100 shares at US$15/share at any time until August 31. For this right, I might pay a premium of, say, US$7. (The premium depends upon sellers' perception of the volatility of the stock, the term of the option, and the difference between the current price and the strike price.) Now, suppose that sometime in August, SLUJ announces a breakthrough that allows them to convert engine sludge into fructose sweetener, and their stock price soars on the news to US$19/share. I might then decide to sell on the news, exercise the option, paying US$1500 for the 100 shares, and then immediately sell them at US$19, realising a profit of US$400 on the shares or, subtracting the cost of the option, US$393 on the trade. Since my original investment was just US$7, this represents a return of 5614% on the original investment, or 22457% annualised. If SLUJ never touches US$15/share, come August 31, the option will expire unexercised, and I'm out the seven bucks. (Since options can be bought and sold at any time and prices are set by the market, it's actually a bit more complicated than that, but this will do for understanding what follows.)
You might ask yourself what would motivate somebody to sell such an option. In many cases, it's an attractive proposition. If I'm a long-term shareholder of SLUJ and have found it to be a solid but non-volatile stock that pays a reasonable dividend of, say, two cents per share every quarter, by selling the call option with a strike of 15, I pocket an immediate premium of seven cents per share, increasing my income from owning the stock by a factor of 4.5. For this, I give up the right to any appreciation should the stock rise above 15, but that seems to be a worthwhile trade-off for a stock as boring as SLUJ (at least prior to the news flash).
A put option is the mirror image: if I bought a put on SLUJ with a strike of 5, I'll only make money if the stock falls below 5 before the option expires.
Now we're ready to construct a genuinely antifragile investment. Suppose I simultaneously buy out of the money put and call options on the same security, a so-called “long straddle”. Now, as long as the price remains within the strike prices of the put and call, both options will expire worthless, but if the price either rises above the call strike or falls below the put strike, that option will be in the money and pay off the further the underlying price veers from the band defined by the two strikes. This is, then, a pure bet on volatility: it loses a small amount of money as long as nothing unexpected happens, but when a shock occurs, it pays off handsomely.
Now, the premiums on deep out of the money options are usually very modest, so an investor with a portfolio like the one I described who was clobbered in 2008 could have, for a small sum every quarter, purchased put and call options on, say, the Standard & Poor's 500 stock index, expecting to usually have them expire worthless, but under the circumstance which halved the value of his portfolio, would pay off enough to compensate for the shock. (If worried only about a plunge he could, of course, have bought just the put option and saved money on premiums, but here I'm describing a pure example of antifragility being used to cancel fragility.)
I have only described a small fraction of the many topics covered in this masterpiece, and described none of the mathematical foundations it presents (which can be skipped by readers intimidated by equations and graphs). Fragility and antifragility is one of those concepts, simple once understood, which profoundly change the way you look at a multitude of things in the world. When a politician, economist, business leader, cultural critic, or any other supposed thinker or expert advocates a policy, you'll learn to ask yourself, “Does this increase fragility?” and have the tools to answer the question. Further, it provides an intellectual framework to support many of the ideas and policies which libertarians and advocates of individual liberty and free markets instinctively endorse, founded in the way natural systems work. It is particularly useful in demolishing “green” schemes which aim at replacing the organic, distributed, adaptive, and antifragile mechanisms of the market with coercive, top-down, and highly fragile central planning which cannot possibly have sufficient information to work even in the absence of unknowns in the future.
There is much to digest here, and the ramifications of some of the clearly-stated principles take some time to work out and fully appreciate. Indeed, I spent more than five years reading this book, a little bit at a time. It's worth taking the time and making the effort to let the message sink in and figure out how what you've learned applies to your own life and act accordingly. As Fat Tony says, “Suckers try to win arguments; nonsuckers try to win.”
After thinking for a few moments, most people will answer with “robust” or one of its synonyms such as “sturdy”, “tough”, or “rugged”. But think about it a bit more: does a robust object or system actually behave in the opposite way to a fragile one? Consider a teacup made of fine china. It is fragile—if subjected to more than a very limited amount of force or acceleration, it will smash into bits. It is fragile because application of such an external stimulus, for example by dropping it on the floor, will dramatically degrade its value for the purposes for which it was created (you can't drink tea from a handful of sherds, and they don't look good sitting on the shelf). Now consider a teacup made of stainless steel. It is far more robust: you can drop it from ten kilometres onto a concrete slab and, while it may be slightly dented, it will still work fine and look OK, maybe even acquiring a little character from the adventure. But is this really the opposite of fragility? The china teacup was degraded by the impact, while the stainless steel one was not. But are there objects and systems which improve as a result of random events: uncertainty, risk, stressors, volatility, adventure, and the slings and arrows of existence in the real world? Such a system would not be robust, but would be genuinely “anti-fragile” (which I will subsequently write without the hyphen, as does the author): it welcomes these perturbations, and may even require them in order to function well or at all.
Antifragility seems an odd concept at first. Our experience is that unexpected events usually make things worse, and that the inexorable increase in entropy causes things to degrade with time: plants and animals age and eventually die; machines wear out and break; cultures and societies become decadent, corrupt, and eventually collapse. And yet if you look at nature, antifragility is everywhere—it is the mechanism which drives biological evolution, technological progress, the unreasonable effectiveness of free market systems in efficiently meeting the needs of their participants, and just about everything else that changes over time, from trends in art, literature, and music, to political systems, and human cultures. In fact, antifragility is a property of most natural, organic systems, while fragility (or at best, some degree of robustness) tends to characterise those which were designed from the top down by humans. And one of the paradoxical characteristics of antifragile systems is that they tend to be made up of fragile components.
How does this work? We'll get to physical systems and finance in a while, but let's start out with restaurants. Any reasonably large city in the developed world will have a wide variety of restaurants serving food from numerous cultures, at different price points, and with ambience catering to the preferences of their individual clientèles. The restaurant business is notoriously fragile: the culinary preferences of people are fickle and unpredictable, and restaurants who are behind the times frequently go under. And yet, among the population of restaurants in a given area at a given time, customers can usually find what they're looking for. The restaurant population or industry is antifragile, even though it is composed of fragile individual restaurants which come and go with the whims of diners, which will be catered to by one or more among the current, but ever-changing population of restaurants.
Now, suppose instead that some Food Commissar in the All-Union Ministry of Nutrition carefully studied the preferences of people and established a highly-optimised and uniform menu for the monopoly State Feeding Centres, then set up a central purchasing, processing, and distribution infrastructure to optimise the efficient delivery of these items to patrons. This system would be highly fragile, since while it would deliver food, there would no feedback based upon customer preferences, and no competition to respond to shifts in taste. The result would be a mediocre product which, over time, was less and less aligned with what people wanted, and hence would have a declining number of customers. The messy and chaotic market of independent restaurants, constantly popping into existence and disappearing like virtual particles, exploring the culinary state space almost at random, does, at any given moment, satisfy the needs of its customers, and it responds to unexpected changes by adapting to them: it is antifragile.
Now let's consider an example from metallurgy. If you pour molten metal from a furnace into a cold mould, its molecules, which were originally jostling around at random at the high temperature of the liquid metal, will rapidly freeze into a structure with small crystals randomly oriented. The solidified metal will contain dislocations wherever two crystals meet, with each forming a weak spot where the metal can potentially fracture under stress. The metal is hard, but brittle: if you try to bend it, it's likely to snap. It is fragile.
To render it more flexible, it can be subjected to the process of annealing, where it is heated to a high temperature (but below melting), which allows the molecules to migrate within the bulk of the material. Existing grains will tend to grow, align, and merge, resulting in a ductile, workable metal. But critically, once heated, the metal must be cooled on a schedule which provides sufficient randomness (molecular motion from heat) to allow the process of alignment to continue, but not to disrupt already-aligned crystals.
When you observe a system which adapts and prospers in the face of unpredictable changes, it will almost always do so because it is antifragile. This is a large part of how nature works: evolution isn't able to predict the future and it doesn't even try. Instead, it performs a massively parallel, planetary-scale search, where organisms, species, and entire categories of life appear and disappear continuously, but with the ecosystem as a whole constantly adapting itself to whatever inputs may perturb it, be they a wholesale change in the composition of the atmosphere (the oxygen catastrophe at the beginning of the Proterozoic eon around 2.45 billion years ago), asteroid and comet impacts, and ice ages.
Most human-designed systems, whether machines, buildings, political institutions, or financial instruments, are the antithesis of those found in nature. They tend to be highly-optimised to accomplish their goals with the minimum resources, and to be sufficiently robust to cope with any stresses they may be expected to encounter over their design life. These systems are not antifragile: while they may be designed not to break in the face of unexpected events, they will, at best, survive, but not, like nature, often benefit from them.
The devil's in the details, and if you reread the last paragraph carefully, you may be able to see the horns and pointed tail peeking out from behind the phrase “be expected to”. The problem with the future is that it is full of all kinds of events, some of which are un-expected, and whose consequences cannot be calculated in advance and aren't known until they happen. Further, there's usually no way to estimate their probability. It doesn't even make any sense to talk about the probability of something you haven't imagined could happen. And yet such things happen all the time.
Today, we are plagued, in many parts of society, with “experts” the author dubs fragilistas. Often equipped with impeccable academic credentials and with powerful mathematical methods at their fingertips, afflicted by the “Soviet-Harvard delusion” (overestimating the scope of scientific knowledge and the applicability of their modelling tools to the real world), they are blind to the unknown and unpredictable, and they design and build systems which are highly fragile in the face of such events. A characteristic of fragilista-designed systems is that they produce small, visible, and apparently predictable benefits, while incurring invisible risks which may be catastrophic and occur at any time.
Let's consider an example from finance. Suppose you're a conservative investor interested in generating income from your lifetime's savings, while preserving capital to pass on to your children. You might choose to invest, say, in a diversified portfolio of stocks of long-established companies in stable industries which have paid dividends for 50 years or more, never skipping or reducing a dividend payment. Since you've split your investment across multiple companies, industry sectors, and geographical regions, your risk from an event affecting one of them is reduced. For years, this strategy produces a reliable and slowly growing income stream, while appreciation of the stock portfolio (albeit less than high flyers and growth stocks, which have greater risk and pay small dividends or none at all) keeps you ahead of inflation. You sleep well at night.
Then 2008 rolls around. You didn't do anything wrong. The companies in which you invested didn't do anything wrong. But the fragilistas had been quietly building enormous cross-coupled risk into the foundations of the financial system (while pocketing huge salaries and bonuses, while bearing none of the risk themselves), and when it all blows up, in one sickening swoon, you find the value of your portfolio has been cut by 50%. In a couple of months, you have lost half of what you worked for all of your life. Your “safe, conservative, and boring” stock portfolio happened to be correlated with all of the other assets, and when the foundation of the system started to crumble, suffered along with them. The black swan landed on your placid little pond.
What would an antifragile investment portfolio look like, and how would it behave in such circumstances? First, let's briefly consider a financial option. An option is a financial derivative contract which gives the purchaser the right, but not the obligation, to buy (“call option”) or sell (”put option”) an underlying security (stock, bond, market index, etc.) at a specified price, called the “strike price” (or just “strike”). If the a call option has a strike above, or a put option a strike below, the current price of the security, it is called “out of the money”, otherwise it is “in the money”. The option has an expiration date, after which, if not “exercised” (the buyer asserts his right to buy or sell), the contract expires and the option becomes worthless.
Let's consider a simple case. Suppose Consolidated Engine Sludge (SLUJ) is trading for US$10 per share on June 1, and I buy a call option to buy 100 shares at US$15/share at any time until August 31. For this right, I might pay a premium of, say, US$7. (The premium depends upon sellers' perception of the volatility of the stock, the term of the option, and the difference between the current price and the strike price.) Now, suppose that sometime in August, SLUJ announces a breakthrough that allows them to convert engine sludge into fructose sweetener, and their stock price soars on the news to US$19/share. I might then decide to sell on the news, exercise the option, paying US$1500 for the 100 shares, and then immediately sell them at US$19, realising a profit of US$400 on the shares or, subtracting the cost of the option, US$393 on the trade. Since my original investment was just US$7, this represents a return of 5614% on the original investment, or 22457% annualised. If SLUJ never touches US$15/share, come August 31, the option will expire unexercised, and I'm out the seven bucks. (Since options can be bought and sold at any time and prices are set by the market, it's actually a bit more complicated than that, but this will do for understanding what follows.)
You might ask yourself what would motivate somebody to sell such an option. In many cases, it's an attractive proposition. If I'm a long-term shareholder of SLUJ and have found it to be a solid but non-volatile stock that pays a reasonable dividend of, say, two cents per share every quarter, by selling the call option with a strike of 15, I pocket an immediate premium of seven cents per share, increasing my income from owning the stock by a factor of 4.5. For this, I give up the right to any appreciation should the stock rise above 15, but that seems to be a worthwhile trade-off for a stock as boring as SLUJ (at least prior to the news flash).
A put option is the mirror image: if I bought a put on SLUJ with a strike of 5, I'll only make money if the stock falls below 5 before the option expires.
Now we're ready to construct a genuinely antifragile investment. Suppose I simultaneously buy out of the money put and call options on the same security, a so-called “long straddle”. Now, as long as the price remains within the strike prices of the put and call, both options will expire worthless, but if the price either rises above the call strike or falls below the put strike, that option will be in the money and pay off the further the underlying price veers from the band defined by the two strikes. This is, then, a pure bet on volatility: it loses a small amount of money as long as nothing unexpected happens, but when a shock occurs, it pays off handsomely.
Now, the premiums on deep out of the money options are usually very modest, so an investor with a portfolio like the one I described who was clobbered in 2008 could have, for a small sum every quarter, purchased put and call options on, say, the Standard & Poor's 500 stock index, expecting to usually have them expire worthless, but under the circumstance which halved the value of his portfolio, would pay off enough to compensate for the shock. (If worried only about a plunge he could, of course, have bought just the put option and saved money on premiums, but here I'm describing a pure example of antifragility being used to cancel fragility.)
I have only described a small fraction of the many topics covered in this masterpiece, and described none of the mathematical foundations it presents (which can be skipped by readers intimidated by equations and graphs). Fragility and antifragility is one of those concepts, simple once understood, which profoundly change the way you look at a multitude of things in the world. When a politician, economist, business leader, cultural critic, or any other supposed thinker or expert advocates a policy, you'll learn to ask yourself, “Does this increase fragility?” and have the tools to answer the question. Further, it provides an intellectual framework to support many of the ideas and policies which libertarians and advocates of individual liberty and free markets instinctively endorse, founded in the way natural systems work. It is particularly useful in demolishing “green” schemes which aim at replacing the organic, distributed, adaptive, and antifragile mechanisms of the market with coercive, top-down, and highly fragile central planning which cannot possibly have sufficient information to work even in the absence of unknowns in the future.
There is much to digest here, and the ramifications of some of the clearly-stated principles take some time to work out and fully appreciate. Indeed, I spent more than five years reading this book, a little bit at a time. It's worth taking the time and making the effort to let the message sink in and figure out how what you've learned applies to your own life and act accordingly. As Fat Tony says, “Suckers try to win arguments; nonsuckers try to win.”
Pablo4.0 out of 5 stars
An interesting idea, and a good read
Reviewed in the United States on May 29, 2024
The bad: Taleb is certainly a very smart person but humbleness is not his forte; there is a feeling throughout the book that he is trying to prove himself smarter than a lot of other people that, maybe yes maybe no, are not dumb themselves. Some of his putdowns are unbecoming of a serious book.
The silly: In one example, Taleb states that he refrains from drinking anything other than "coffee, tea, milk or wine" because those drinks have been tested through years to be safe. He conveniently forgets that milk is safe NOW because of that little invention called pasteurization, and that other drinks such as beer have also been around for thousands of years. But this is minor.
The good. it IS a very interesting idea, and Taleb makes a good case. He names and notices many instances in which his concept is solidly grounded, and discusses some in which it will not apply, leaving a lot of thinking to be done by the reader. As with his BLACK SWAN, the idea is profound and worth considering, and he makes a very good case for it. Overall, a very recommended book, if you remind yourself that you want your mind to be antifragile too and subjecting it to this idea may be a good way of doing so.
The silly: In one example, Taleb states that he refrains from drinking anything other than "coffee, tea, milk or wine" because those drinks have been tested through years to be safe. He conveniently forgets that milk is safe NOW because of that little invention called pasteurization, and that other drinks such as beer have also been around for thousands of years. But this is minor.
The good. it IS a very interesting idea, and Taleb makes a good case. He names and notices many instances in which his concept is solidly grounded, and discusses some in which it will not apply, leaving a lot of thinking to be done by the reader. As with his BLACK SWAN, the idea is profound and worth considering, and he makes a very good case for it. Overall, a very recommended book, if you remind yourself that you want your mind to be antifragile too and subjecting it to this idea may be a good way of doing so.