Book Summary: Nassim Nicholas Taleb “The Black Swan”
A Black Swan is a rare, high-impact event that catches us by surprise. It has three characteristics:
- It is an outlier in the sense that it cannot be expected based on the past
- It is impactful
- We can (and do) rationalize explanations after the fact to the point that we end up believing it could have been predicted
While the concept of the Black Swan gives name to the book, perhaps even more interesting are the concepts of Extremistan and Mediocristan.
Mediocristan is an area where a single observation cannot wildly change the average. In this terrain, we can simplify reality into averages and other statistic shortcuts without too much distortion. Human height lives in Mediocristan: no human is short enough or tall enough to drastically change the average height of humanity — not even the average height of a small town.
Extremistan is an area where a single observation can disproportionately impact the aggregate. In this type of terrain, statistical shortcuts are misleading, so failing to identify what type of terrain you are in can lead to catastrophe.
Furthermore, Taleb believes that a small number of black swans are responsible for almost everything, so our understanding of Mediocristan is not useful as often as we think. To make matters even worse, our minds trick us into thinking we are in Mediocristan even when we are not, so we use the wrong toolkit to estimate risks.
It is as if humans have been set up to fall for the Mediocristan trap: we overestimate how much of the terrain belongs to Mediocristan and we have a strong toolkit to operate in Mediocristan, so we default to the Mediocristan toolkit.
We suffer from epistemic arrogance (overestimating what we know and underestimating uncertainty), survivor bias (drawing conclusions from winners while ignoring the silent graveyard of losers) and narrative fallacy (creating stories around facts, forcing logic into the data).
Nassim uses the turkey to illustrate how easily one can get fooled by data. Nassim speaks of the turkey that is fed day after day and the longer feeding goes on, the more comfortable he feels, oblivious to the reality that slaughter is getting closer and closer. The turkey assumed that observations of the past would be representative of the future1.
At times, we are not mere turkeys and we actively tilt chances towards disaster. Taleb points our that nature over-invests in redundancy (two kidneys, not one), while modern optimization culture strips it out in the name of efficiency, leaving systems fragile.
That idea made me think of how I’ve been approaching investments and an idea that felt like a gut punch is that popular investment advice is to diversify risk, but Taleb made me see that doing that is just averaging out the risk, which is not the same as limiting it.
My dad, who retired early and focused on managing the family wealth, has reminded me repeatedly over the years: if you lose 20%, a gain of 20% is not enough to get you back to where you were. This is known as the asymmetry of losses. It is the other side of the coin in compounding: the drag of losses can be severe enough in the long term that avoiding ruin may (but doesn’t necessarily) outperform chasing average returns.
All these concepts lead Taleb to propose the barbell strategy: don't lose big. Ever. Then swing aggressively with a small portion you can afford to lose.
Nassim disagrees with Adam Smith as much as with Marx: “free markets work because they allow people to be lucky”, not because they reward skill. The corollary is to take wild swings and tinker as much as possible to maximize one’s exposure to positive Black Swans.
On top of that, I tie this matter to my wealth principles. One of them is: Wealth gives peace of mind. If it increases stress or reduces security, it’s not wealth.
After the release and success of the book, Nassim was convinced that he had an obligation to at least try to make the horse drink. And so, second edition added a postscript essay to address that. I have to admit that, even with the additional essay, I struggle to reach the water.
I am not quite a turkey. I don’t feel safer with every feeding. I am more like a turkey who sees the knife coming and hasn't moved. I need to take action, but the barbell strategy is easier to understand than to implement. I've started — the defensive side is taking shape. The aggressive side remains fuzzy. But Taleb would probably say that's the right order. First, make sure you can't be wiped out. Then, swing as much as you can.
LSS: Iron Butterfly 'In-A-Gadda-Da-Vida'
Ironically, Taleb picks an unverifiable narrative, since we don’t truly know if the turkey grows more trusting every day. Perhaps he falls victim himself to the narrative fallacy, but the illustration works.↩