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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

#91

Post by yorwba »

ThrowMeDown01 wrote: post #79
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.

As the blog post rightly said, they present 538 present the forecast in a way that they are never wrong. I can see the point. I also fond the comparison of NFL vs. Senate forecasts meaningful. This kind of "forecasting" seems to be the current version of crystal balling and astrology. They (models) don't really know anything (no causation, and definitely nothing close to an actual model of the real world like in phys…

> As the blog post rightly said, they present 538 present the forecast in a way that they are never wrong.

The whole point of probabilistic modeling is to replace absolute decisions like "right or wrong" by continuous weights on the possibilities. If you absolutely need a definite decision, you can sample a prediction according to the probability assigned by the model. If the true outcome is x and the model assigned it probability p, then that procedure is going to be wrong (1-p) of the time. You could define that number as the "wrongness" of the probabilistic model, as a continuous analog of the definite case.

The advantage of probabilistic modeling is that you can also ask how wrong the model expects to be and get a meaningful answer. If there are many possible outcomes and none of them very likely, any choice is going to be wrong a lot. But you should expect a good model to have a small difference between its expected and actual wrongness. One might call that value "honesty".

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

#92

Post by OscarCunningham »

cm2012 wrote: post #11
tareqak wrote: post #5

As a non-specialist, I like how the discussion boils down the picture at the end: https://cdn-images-1.medium.com/max/1600/1*D_tidaT-fHMY3DRLg... in that it is something I can understand.

Nate Silver always calls the nowcast (blue line) for what it is - a forecast for if the election was held that day. The forecast, made a few days before election day, is the official forecast and the one that beats most other estimates.

That blue line is a record of Silver's forecast, not the nowcast. You can compare them here https://projects.fivethirtyeight.com/2016-election-forecast/

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

#93

Post by logifail »

_0ffh wrote: post #85
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.

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?

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

#94

Post by safgasCVS »

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…

Unlikely. Taleb seems to like how his argument has been summarised.

The crux of the issue taleb has with silver is showing probabilities without making a decision/declaration is cowardly. When asked about making a prediction he says one thing then follows it up with a “ but don’t be surprised if it could be completely random.” And that’s the point - the fact he covers his ass is the problem. Election forecasting is hard so don’t pretend you know something you don’t if you won’t stake something on your predictions. Oh so it could be anything and you don’t want to be held accountable? Then don’t say a damn thing. Basically Silver never wants to be held accountable for his models but always have uncertainty covering his ass as a cop out. so I’m With taleb on this one. Either silver makes a claim and sticks with it or don’t show probabilities and pretend he knows things

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

#95

Post by OscarCunningham »

I think the difference in opinion is caused by Taleb modelling the election as though all of the uncertainty is caused by the fact that people might change their minds, whereas Silver is also including the uncertainty from polling errors.

Silver's predictions fluctuate a lot as time passes. Taleb is assuming that all of these fluctuations are caused by the electorate changing who they're going to vote for. Then he says "if you knew people's opinions were as volatile as this, you shouldn't have been so confident earlier!", or words to that effect. If lots of people will change their minds, then early polling won't be very informative about the final result.

But the fluctuations in Silver's predictions are actually caused by his changing certainty about how accurate the polls are. Silver does take into account that people might change their minds, but this isn't the cause of most changes in his predictions. So people actually change their minds a lot less often than Taleb's model of Silver's model suggests. This is why Silver can make strong predictions early on.

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

#96

Post by OscarCunningham »

safgasCVS wrote: post #94
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…

Unlikely. Taleb seems to like how his argument has been summarised. The crux of the issue taleb has with silver is showing probabilities without making a decision/declaration is cowardly. When asked about making a prediction he says one thing then follows it up with a “ but don’t be surprised if it could be completely random.” And that’s the point - the fact he covers his ass is the problem. Election forecasting is h…

I disagree. Probabilities can be useful even if they're not 0% or 100%. For example weather forecasts often give the probability of rain. My plans will be different if the probability is 20% vs 80%. My plans don't tend to vary based on who wins the election, but I imagine that that information is very useful to some people.

And if your data is telling you to be 80% sure, I don't think you should fudge it and claim 100%. Report the uncertainty that you actually have.

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

#97

Post by coldtea »

coldtea wrote: post #71
VintageCool wrote: post #58

Earlier quoted context omitted.

The 2016 election was swingy and it was uncertain. In 2008 and 2012, the political media was myopically focused on the twists and turns of the horse race and called it 50-50 dead even. Nate Silver's 538 modeled the election as basically stable with only small polling shifts, and the only change in the last month was a steady decline in the remaining time that McCain (or Romney) had to significantly shift the polls. I…

> The 2016 election was swingy and it was uncertain. In retrospect. In real life, only a few pundits called it from the start (even explaining the mechanics, including Taleb and that Dilbert guy). Most of the press and pundits was all certain about a specific outcome until the very last minute.

correction: called it [as such, i.e swingy]

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

#98

Post by elgenie »

VintageCool wrote: post #55
hn_throwaway_99 wrote: post #37

Earlier quoted context omitted.

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…

This "Twitter fight" began with Nate Silver talking to the media, trying to convey both his prediction and its uncertainty: https://thehill.com/homenews/sunday-talk-shows/414759-nate-s... > "So in the House we have Democrats with about a 4 in 5 chance of winning," Silver told ABC's "This Week." > "But no one should be surprised if they only win 19 seats and no one should be surprised if they win 51 seats," Silver add…

The final 538 pre-election forecast is available here: https://projects.fivethirtyeight.com/2018-midterm-election-f... (it moved slightly towards Dems in the last few days)

Silver's point is that their model results in a probability distribution of outcomes and, at the time he was commenting, in 10% of the cases Dems won 19 or fewer seats, resulting in a GOP majority, and in 10% of cases Dems won 51 or more seats, resulting in an overwhelming Dem majority.

That those extremes were approximately equally likely (in CDF terms) tails is willfully missing the point that the vast majority of the 80% of outcomes in the middle between those relatively fat tails involved Democrats winning, which is why the prediction was a 4 in 5 chance of Dems retaining control.

By missing that rather obvious point, D'Souza unsurprisingly comes off as a moron and Taleb also fails to cover himself in glory.

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

#99

Post by [deleted] »

ummonk wrote: post #72
VintageCool wrote: post #55

Earlier quoted context omitted.

This "Twitter fight" began with Nate Silver talking to the media, trying to convey both his prediction and its uncertainty: https://thehill.com/homenews/sunday-talk-shows/414759-nate-s... > "So in the House we have Democrats with about a 4 in 5 chance of winning," Silver told ABC's "This Week." > "But no one should be surprised if they only win 19 seats and no one should be surprised if they win 51 seats," Silver add…

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.

[deleted]

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

#100

Post by dagw »

starchild_3001 wrote: post #17
mhb wrote: post #14

Shouldn't a guy like Taleb be able to propose a bet with Silver that demonstrates he (Taleb) is right?

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

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