A Take on Taleb's Take...

 A popular Twitter thread on N. Taleb's Real World Risk Institute's 2-week program:

https://twitter.com/emigal/status/1459647941396910086

Taleb On the Pandemic

Nassim Taleb recently on the pandemic, risk, fat tails, etc. (hour+ podcast), with an odd digression to geronticide toward the end:

https://www.listennotes.com/podcasts/econtalk/nassim-nicholas-taleb-on-the-i3JgS0nsF6W/

Summary/review of the podcast here:

https://podcastnotes.org/econtalk/nassim-nicholas-taleb-on-econtalk/

"Complex systems..."

This Sunday's reflection:

"Complex systems are full of interdependencies -- hard to detect -- and nonlinear responses. 'Nonlinear' means that when you double the dose of say, a medication, or when you double the number of employees in a factory, you don't get twice the initial effect, but rather a lot more or a lot less. Two weekends in Philadelphia are not twice as pleasant as a single one -- I've tried. When the response is plotted on a graph, it does not show as a straight line ('linear'), rather as a curve. In such environments, simple causal associations are misplaced; it is hard to see how things work by looking at single parts."

-- Nassim Taleb in "Antifragile"

Taleb Provokes...

Interesting short reading (pdf download) a few days back, "On Things That Do Not Average or the Mean Field Problem," from irascible Nassim Taleb in what I presume is an excerpt (preliminary draft) from his next book:

dl.dropboxusercontent.com/u/50282823/meanfield.pdf

 In it, he rebukes "psychology, 'evolutionary theory,' game theory, behavioral economics, neuroscience and similar fields not subjected to proper logical (and mathematical) rigor" (...can't believe he left out epidemiology ;-) for their inadequacy in dealing with nonlinearity.

Toward the end he writes:

"Much of the local research in experimental biology, in spite of its seemingly 'scientific' and evidentiary attributes fail a simple test of mathematical rigor.
"This means we need to be careful of what conclusions we can and cannot make about what we see, no matter how locally robust it seems. It is impossible, because of the curse of dimensionality, to produce information about a complex system from the reduction of conventional experimental methods in science. Impossible." 

On a side-note, a guest post in October at Cathy O'Neil's blog drew LOTS of comments pro-and-con about the likelihood that computer scientists will ever truly simulate the human brain (with huge MONEY being poured into such projects).
Taleb makes it clear here that he's in the camp arguing we will "never" understand the 
workings of the brain based on an understanding its parts, and not because it is too difficult, but because it is mathematically "impossible."


ADDENDUM: yesterday, Taleb followed up the above paper with this far more technical version (again pdf) on the subject:

https://t.co/gTpPZwPU1C

(image: via SThought/WikimediaCommons  )

A Tenet From Taleb

A quick Sunday reflection from Nassim Taleb in "Antifragile":

"...let me express my rule as follows: what Mother Nature does is rigorous until proven otherwise; what humans and science do is flawed until proven otherwise."

[...recently finished reading Taleb's 2012 "Antifragile" and enjoyed it even more than his prior "The Black Swan" and "Fooled By Randomness". The last third of the irascible volume is especially good. Recommended.]

Black Swans…

Today's Sunday reflection comes from the "Prologue" to Nassim Taleb's "The Black Swan":

"Before the discovery of Australia, people in the Old World were convinced that all swans were white, an unassailable belief as it seemed completely confirmed by empirical evidence. The sighting of the first black swan might have been an interesting surprise for a few ornithologists… but that is not where the significance of the story lies. It illustrates a severe limitation to our learning from observations or experience and the fragility of our knowledge. One single observation or experience can invalidate a general statement derived from millennia of confirmatory sightings of millions of white swans….
"I push one step beyond this philosophical-logical question into an empirical reality, and one that has obsessed me since childhood. What we call here a Black Swan is an event with the following three attributes.
"First, it is an outlier, as it lies outside the realm of regular expectations, because nothing in the past can convincingly point to its possibility. Second, it carries an extreme impact. Third, in spite of its outlier status, human nature makes us concoct explanations for its occurrence after the fact, making it explainable and predictable.
"I stop and summarize the triplet: rarity, extreme impact, and retrospective (though not prospective) predictability. A small number of Black Swans explain almost everything in our world, from the success of ideas and religions, to the dynamics of historical events, to elements of our own personal lives. Ever since we left the Pleistocene, some ten millennia ago, the effect of these Black Swans has been increasing. It started accelerating during the industrial revolution, as the world started getting more complicated, while ordinary events, the ones we study and discuss and try to predict from reading the newspapers, have become increasingly inconsequential"…..

"…I stick my neck out and make a claim, against many of our habits of thought, that our world is dominated by the extreme, the unknown, and the very improbable (improbable according to our current knowledge) -- and all the while we spend our time engaged in small talk, focusing on the known, and the repeated. This implies the need to use the extreme event as a starting point and not treat it as an exception to be pushed under the rug."


[Meanwhile, over at MathTango this morning a new interview with one of my favorite current math writers, Richard Elwes.]


 

Taleb on Randomness

Today, a number of bits from an older Nassim Taleb volume, "Fooled By Randomness":

"Probability is not a mere computation of odds on the dice or more complicated variants; it is the acceptance of the lack of certainty in our knowledge and the development of methods for dealing with our ignorance. Outside of textbooks and casinos, probability almost never presents itself as a mathematical problem or a brain teaser. Mother Nature does not tell you how many holes there are on the roulette table, nor does she deliver problems in a textbook way (in the real world one has to guess the problem more than the solution)."

"This book is about luck disguised and perceived as nonluck (that is skills) and, more generally, randomness disguised and perceived as non-randomness (that is, determinism). It manifests itself in the shape of the lucky fool, defined as a person who benefited from a disproportionate share of luck but attributes his success to some other, generally very precise, reason."

"We are still very close to our ancestors who roamed the savannah. The formation of our beliefs is fraught with superstitions -- even today (I might say especially today). Just as one day some primitive tribesman scratched his nose, saw rain falling, and developed an elaborate method of scratching his nose to bring on the much-needed rain, we link economic prosperity to some rate cut by the Federal Reserve Board, or the success of a company with the appointment of a new president 'at the helm.'"

"Disturbingly, science has only recently been able to handle randomness (the growth in available information has been exceeded only by the expansion of noise). Probability theory is a young arrival in mathematics; probability applied to practice is almost nonexistent as a discipline"

"Indeed, probability is an introspective field of inquiry, as it affects more than one science, particularly the mother of all sciences: that of knowledge. It is impossible to assess the quality of the knowledge we are gathering without allowing a share of randomness in the manner it is obtained and cleaning the argument from the chance coincidence that could have seeped into its construction. In science, probability and information are treated in exactly the same manner. Literally every great thinker has dabbled with it, most of them obsessively."


[…If you have a favorite math-related passage that might make a nice Sunday morning reflection here let me know (SheckyR@gmail.com). If I use one submitted by a reader, I'll cite the contributor.]