I’ve been on a Taleb streak this year (here, here and here). Nassim Nicholas Taleb, that is, the options trader-turned-mathematician-turned public intellectual (and I even managed to get myself on his infamous blocklist after arguing back at him). Many years ago, I read Fooled by Randomness but for some reason it didn’t resonate with me and I wasn’t seeing the brilliance.
Last spring, upon reading former poker champion Annie Duke’s Thinking in Bets and physicist Leonard Mlodinow’s The Drunkard’s Walk, I plunged into Taleb land again, voraciously consuming Fooled, The Black Swan and Skin in the Game, followed by Antifragile just a few months ago.
Taleb is a strange creature; vastly productive and incredibly successful, everything he touches does not quite become gold, but surely stirs up controversy. What he’s managed to do in his popular writing (collected in the Incerto series) is to tie almost every aspect of human life into his One Big Idea (think Isaiah Berlin’s hedgehog): the role of randomness, risk and uncertainty in everyday life.
One theme that comes up again and again is the idea of redundancies: having several different and overlapping systems – back-ups to back-ups – that minimize the chance of fatally bad outcomes. The failures of one of those systems will not result in the extremely bad event you’re trying to avoid.
Focusing primarily on survivability – “absorbing barriers” – through the handed-down wisdom of the Ancients and the Classic, the take-away lesson for Taleb in almost all areas of life is overlapping redundancies. Reality is complicated, and the distribution from which events are drawn is not a well-behaved Gaussian normal distribution, but one of thick tails. How thick nobody knows, but wisdom in the presence of absorbing barriers suggest that taking extreme caution is a prudent long-term strategy.
Of course, in the short run, redundancy amounts to “wasted” resources. In chapter 4 of Fooled, Taleb relates a story from his option trading days where a client angrily calling him up about tail-risk insurance he had sold them. The catastrophic event from which the insurance protected had not taken place, and so the client felt cheated. This behavior, Taleb maintains quite correctly, is idiotic. After all, if an insurance company’s clients consist of only soon-to-be claimants, the company won’t exist for long (or it prices insurance at prohibitively high rates, undermining the business model).
Same thing applies for one of his verbose rants about airline “efficiency,” a rather absurd episode of illustrating “asymmetry” – the idea that downside risks are larger than upside gains. Consider a plane departing JFK for London, a trip scheduled to take 7h trip. Some things can happen to make the trip quicker (speedy departure, weather conditions, landing slot available etc), but only marginally; it would, for instance, not be possible to arrive in London after only an hour. In contrast, the asymmetry arises as there are many things that can delay the trip from mere minutes to infinity – again, weather events, mechanical failures, tech or communication problems.
So, when airlines striving to make their services more efficient by minimizing turnaround time – Southwest’s legendary claim to fame – they hit Taleb’s antifragile asymmetry; getting rid of redundant time on the ground, makes the process of on-loading and off-loading passengers fragile. Any little mistake can cause serious delays, delays that accumulate and domino their way through crowded airport networks.
Embracing redundancies would mean having more time in-between flights, with extra planes and extra mechanics and spare parts available at many airports. Clearly, airlines’ already brittle business model would crumble in a heartbeat.
The flipside efficiency is Taleb’s redundancy. Without optimization, we constantly use more than we need, effectively operating as a tax on all activity. Taleb would of course quibble with that, pointing out that the probability distribution of what “we need” must include Black Swan events that standard optimization arguments overlook.
That’s fine if one places as high a value on risks that Taleb does, and indeed they’re voluntarily paid for. If customers wanted to pay triple the money for airfares in order to avoid this or that delay, there is a market for that – it just seems few people value that price over the damage from (low-probability) delays.
Another example is earthquake-proving buildings that Nate Silver discussed in his The Signal and the Noise regarding the Gutenberg-Ritcher law (the reliably inverse relationship between frequency and magnitude of earthquakes). Constructing buildings that can withstand a high-magnitude earthquake, say a one-in-three-hundred-year event is something rich Californians or Japanese can afford – much-less so a poor country like the Philippines. Yes, Taleb correctly argues, the poor country pays its earthquake expenses in heightened risk of devastating damage.
Large redundancies, back-ups to back-ups, are great if you a) can afford them, and b) are risk-averse enough. Judging by his writing, Taleb is – ironically – far out along the right-tail of risk aversion; for most other people, we have more urgent needs to look after. That means occasionally “blowing up” and suffer hours and hours of airline delays or collapsing buildings after an earthquake.
Taleb rarely considers the trade-offs, and the different subjective value scales (or discount rates!) that differ between people. While Taleb may cherish his redundancies, most of us would rather eliminate them for asymmetrically small gains.
Insurance is a relative assessment of price and risks. Keeping a reserve of redundancies are subjective choices, not an objective necessities.