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Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

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Re: Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

#101

Post by OscarCunningham »

darawk wrote: post #64
comex wrote: post #41

Earlier quoted context omitted.

I don’t have the background knowledge to properly understand the math in that paper. But I do know that you can’t simply set bounds a priori on how much a probability can change after additional information has been gathered; no matter how pathological the swings, you can design a system, and a series of observations of that system, that would make all the forecasts (i.e. conditional probabilities) correct. Thus the…

I believe he's making a slightly more subtle point. It's not just that the forecasts are swinging too much, it's that they're swinging too much too early. Consider an option on a stock (which is the analogy Taleb is making here). If you buy a 1 year call option on AAPL and tomorrow they announce that they beat earnings by 10%, that's not a huge deal for you. If on the other hand, you owned a 1-week expiration call, i…

I think that Taleb's problem is that he thinks all the uncertainty in Silver's model comes from the fact that people might change their minds about who to vote for.

This is why Taleb can't make a model that fits Silver's forecasts. Silver could only be confident early on if he knew that people weren't going to change their minds much. But if people don't change their minds much then Silver's forecast shouldn't fluctuate much as time passes. Alternatively, if the forecast fluctuates a lot, it must be because lots of people are changing their minds. But then Silver shouldn't have been so confident to begin with!

But in fact the uncertainty in Silver's model isn't (wholy) caused by the possibility that people change their minds. It's mostly caused by the possibility of polling error. As we approach the election people have less time to change their minds, but the possibility of polling error doesn't change. This why Taleb can't create a model under which Silver's forecasts are rational; he's not taking into account polling error.

Re: Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

#102

Post by OscarCunningham »

potatofarmer45 wrote: post #27

Nate Silver built an aleatory model whereby low probability high effect events (Comey reopening the investigation on eve of the election) are discounted because if you add enough of these potential disruptive events the model will be 50%-50% and that has no value to anybody. Who wants to read an article that said "election forecast 50-50" every day. If a 538 model says one outcome is 75% probable, it really should co…

I don't think this is a good description of Silver's model. It doesn't discount disruptive events at all. It implicitly takes them into account.

Silver knows that people's opinions can be changed by events that happen before the election. This is why polls taken early on are less informative about the final result than polls taken closer to the day. Based on historical records, Silver knows how the accuracy of polls depends on the date they are taken, and he weights them accordingly. This process automatically models the possibility that an event could suddenly change people's opinions just before the election. It's taken into account in terms of the accuracy of polls.

Re: Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

#103

Post by n-gatedotcom »

logifail wrote: post #93
_0ffh wrote: post #85

Earlier quoted context omitted.

Yeah, essentially "extremely possible" is just "far from impossible". Something can be very possible but still not very likely, surely?

If you say that X is extremely possible does that mean that X is unlikely to happen (probably won't), or that X is very likely to happen (probably will)? I'd never come across anyone using this phrase until Nate Silver did. Is it a US English thing?

Read very much

Re: Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

#104

Post by MattHeard »

logifail wrote: post #76
ummonk wrote: post #72

Earlier quoted context omitted.

I normally like Taleb's insights but it was obvious when following this that he (and Dinesh D'Souza) were ridiculously misconstruing Nate Silver's comment. Two outcomes being "extremely possible" in no way means they have a 50/50 chance of happening. It merely means that neither outcome has a low enough chance that you should assume it won't happen.

>> Two outcomes being "extremely possible" What on earth is a professional like Silver doing using the word "extremely" in that context? If I'd have written that kind of statement in school, the teacher would have crossed it out in red pen and told me to rephrase. If I toss a coin, are the outcomes "heads" and "tails" both supposed to be "extremely possible", with "landing on its edge" being merely "unlikely"? (In ca…

Both events are extreme yet possible.

Re: Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

#105

Post by JadeNB »

scythe wrote: post #86
JadeNB wrote: post #83

Earlier quoted context omitted.

> He compared a very lopsided win to a slight loss, and those were equally likely. I'm not arguing with you, since the one thing I know is that there's no surer way to making a mistake than jumping in confidently on probabilistic issues, especially issues of interpretation rather than of pure mathematics; but I think you must have misspoke, or I must have misunderstood. The quoted sentence says 'extremely probable' (…

Not "extremely probable" -- it says "extremely possible ", which is a malapropism or a new phrase. It's easy to mistake because it has no clear meaning. The comparison, though, does not appear to be D's win vs D's lose, but D's win by more than X vs D's lose, and the latter clearly (imo) suggests D is favored to win.

> Not "extremely probable" -- it says "extremely possible", which is a malapropism or a new phrase. It's easy to mistake because it has no clear meaning.

Indeed, despite quoting it in my response, I made exactly that mistake. Thanks!

Re: Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

#106

Post by lixtra »

pmart123 wrote: post #33

I liked the first chapter of "Fooled by Randomness," but I stopped reading the book when each chapter regurgitated the same points, each more nihilistic than the last. Perhaps Taleb should concentrate on the accuracy of his own predictions: https://www.businessinsider.com/taleb-every-single-human-bei... >>> "every single human being" should bet U.S. Treasury bonds will decline. >>> Short the S&P vs Long Gold, in a 5…

To be fair this has to be seen in context (in the linked article):

> Hyperinflation bet that could very well not work but if it does "you will never fly in a public jet again."

So it's a bet on a small probability with very high payout. This approach worked for him in the past.

Re: Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

#107

Post by dgroshev »

I'm profoundly confused by the deep respect Taleb commands in the eyes of many people here, apparently. The guy has a few good ideas that he repeats ad nauseam, but he punches way over his own intellectual weight too often. A few especially egregious examples are his deranged GMO hate "paper" which is profoundly ignorant of the involved biology [1], his support of Syrian government's slaughter of civilians [2][3], and his Putinversteher views ([4] reads as a parody for anyone knowing anything about Putin and modern Russia). Combined with his unlimited arrogance, I don't understand how people can respect him intellectually.

[1]: http://www.fooledbyrandomness.com/pp2

[2]: https://medium.com/opacity/the-syrian-war-condensed-a-more-r...

[3]: https://medium.com/@ameraidi/nassim-taleb-is-wrong-on-syria-...

[4]: https://twitter.com/nntaleb/status/773323163509850112

Re: Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

#108

Post by ggambetta »

hn_throwaway_99 wrote: post #37
mturmon wrote: post #25

This is an intellectually confused post. It is so unclear and muddled that only a charitable reader would suppose the author understands the mathematical and modeling issues here. I’m surprised the author published it in this form - you don’t want to jump into a controversy like this with such an unclear discussion. As just one example, the whole digression on a “decision boundary” is conceptually mistaken. Once you…

Agreed. The more I read the more I got embarrassed for the author, mainly because his points were so ridiculously flimsy. I thought this was one of the worst: > Because FiveThirtyEight only predicts probabilities, they do not ever take an absolute stand on an outcome: No ‘skin in the game’ as Taleb would say. This is not, however, something their readers follow suit on. In the public eye, they (FiveThirtyEight) are j…

Author also doesn't seem to understand what "skin in the game" means.

Re: Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

#109

Post by zimablue »

OscarCunningham wrote: post #90
zimablue wrote: post #87

To try and explain Taleb's argument as simply as possible: If someone tells you today that an event is 100% certain, and tomorrow tells you that it is impossible, then you intuitively will not trust their forecasting. If it's certain, then it's certain not to be impossible tomorrow Now if someone tells you something is a 90% chance today, and a 10% chance tomorrow, again you don't trust their predictions. There is a…

> Now Nate Silver accepts this, but says that he's not actually putting a probability on the event in the future, but some non-existent "probability on that event in the future if the future was now". Could you link to where Silver discusses this? I'm interested in seeing his description of exactly what his numbers mean.

https://fivethirtyeight.com/features/a-users-guide-to-fiveth...

What I'm referring to is the "now-cast", but his other two definitions both seem to shy away from saying "this is flat-out the probability we think of the election".

The point is, you can redefine or choose a definition of probability if you want, but if it's less useful than the normal definition (and confusing to people!) then people are free to criticize your work on that basis.

And there's a very useful, testable, mathematical definition of probability that allows us to equally assess everyone's predicting ability, and Nate Silver is dodging it.

If you're interested in this subject, there's a non-mathematical discussion somewhere in Tetlock's book Superforecasting which is interesting in general.

Re: Why we should care about the Nate Silver vs. Nassim Taleb Twitter war

#110

Post by lixtra »

dagw wrote: post #100
starchild_3001 wrote: post #17

Earlier quoted context omitted.

Best solution proposed here! Put your money where your mouth is Taleb and Silver! Btw, I read 3 of Taleb's books, 1 from Nate Silver. Both are pretty good. Taleb is the more original, but also more often-objectionable.

Best solution proposed here So what should the bet be? As far as I can tell they're not disagreeing on anything that can easily be reduced to a bet

Nate calls the chances like 80:20 Clinton:Trump. Taleb takes the side: 100,000 USD that Trump wins. If Trump wins, Nate pays 500,000 to Taleb. If Clinton wins, than Taleb pays 100,000 USD to Nate.

Do this for each election.

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