Comment by rurp
8 hours ago
I had complaints about 538, especially the early days, but don't understand this critique at all. A 30% chance hitting is completely unremarkable, and it was a perfectly reasonable reading of the evidence at the time. Nate isn't wrong that conventional wisdom was way off, with even supposedly statistical models giving Hillary a 99% chance of winning.
Elections, like many things, have some inherent uncertainty. A several point polling error is normal, so a candidate who is down a couple points on election day has a decent shot of winning.
Discussion of stats models is always complicated by the fact that a lot of people will read "30%" as a "no" prediction and claim your model is wrong if the thing happens. On the one hand, one strategy is to "hide" the numbers a bit behind a blaring headline that says "we are not sure!!" It's a bit of an art to decide when to be "sure" or not. On the other hand, in research for example you can just say screw it, I care if the correct people are correct, not if a bunch of wrong people are wrong.
I feel like the correct strategy for 538 when it was actually niche was to be precise, but then it went viral and maybe should've hit the IDK button much harder and more often after that.
The real caveat is that 538 was a Monte Carlo model, and is only as good as its inputs. "Here's what the current spread in polling numbers is *given our model and the current polling and their reported uncertainties.*" Polling uncertainties are themselves computed under certain models, and those models are subject to errors. I don't think 538 hid this, but it's a difficult caveat for people to reason about because the sorts of modeling errors that have the most influence usually represent "unknown unknowns".
Building a model for predicting the ultimate winner of a US presidential election is particularly difficult, because you are dealing with noisy input data and nonlinear effects, i.e. just a few thousand votes in a few key states can completely flip the outcome. If you then have poorly calibrated polls with a large margin of error, there is really nothing much you can do.
On the other hand, it does raise the question how valuable the 538 models for something like this really are if the outcome is a coin flip anyway.
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Regularly referring to that ~30% spread as "one polling error" made this a lot more understandable than most statistics for many people.
That's a core mechanic in games like Dispatch.
People don't like seeing a 95% chance of winning and then losing. The game tweaks the odds, so certain thresholds become gimmes (something like "if the displayed odds are better than 75%, treat them as 100%").
That's stupid. That would piss me off.
Fire Emblem does something complex with averaging random numbers to do the same thing - a 95% chance to hit becomes 99.5, and the reverse for low percentages.
Conversely weather forecasters report a 40% chance of rain when the actual chance is 10% or similar.
So I have a bit of sympathy for people who don't have a good intuition for probabilities, given that the world is constantly gaslighting them.
> Discussion of stats models is always complicated by the fact that a lot of people will read "30%" as a "no" prediction and claim your model is wrong if the thing happens.
I've even heard things like "70% chance of Hillary winning means she gets 70% of the votes!" (and tangentially, my far-too-long argument with someone on Reddit who insisted "there is no way in hell 50% of the people in this town make above the median income"...)
I don't understand why this is surprising. People didn't go to FiveThirtyEight to marvel the science behind it. The science was just supposed to give you what you came there for: the actual election results.
In the end, it turned out that predicting elections is still very hard, and that for all the fanfare, FiveThirtyEight performed only slightly better than what you could find in any other reputable newspaper, so it kinda lost its appeal.
> it turned out that predicting elections is still very hard
So maybe we shouldn't be doing it. The value of predicting an election in the large out in public seems kind of dubious, and it's more like gambling than actually being useful. A candidate only runs, and continues running, if they think they can win. All predictions like these do is confuse voters leading up to election day and while they are voting. It keep candidates from making strong cases for their platform, keeps the voters from listening to the candidates' platforms, and encourages team-based partisan politics.
> FiveThirtyEight performed only slightly better than what you could find in any other reputable newspaper
FiveThirtyEight gave Trump double the odds of the next highest reputable prediction, which was The New York Times Upshot (15%). Princeton Election Consortium gave Trump less than 1%.
That is not "only slightly better" to anyone who's statistically literate.
A FiveThirtyEight reader in 2016 was significantly better calibrated regarding Clinton’s chances than a reader of other reputable newspapers.
This embodies what 538 and its defenders miss about 538's appeal:
People didn't come to 538 for explanations on subtle points of statistical literacy (although those were provided). They came because, for whatever reason, they wanted to know who would win the election.
People not trained in statistics treated like the scoreboard at a football game- it's always better to be winning, but score is a near perfect predictor in the last minute.
Once 538 stopped delivering perfect predictions and started delivering "Actually the difference between 1% and 30% are way bigger than you think" lectures, the appeal disappeared. There are better places to learn math from.
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538 was never about magically making polls more reliable, and only people that don't understand what polls are could think that (caveat: lots of people don't understand how polls work).
538 was about analyzing and communicating the information from those polls in an easily accessible form. If you came to the site for that, you weren't mad that they "predicted poorly something that was impossible to predict from the data sources they used" ... you were just mad at Trump for winning (despite polls suggesting otherwise).
Again, I don't think any of this matters. People were not coming there to have "information communicated to them". They were coming there for the satisfaction of knowing the results before everyone else. And FiveThirtyEight couldn't realistically deliver on that.
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Polls became much less interesting as an Entertainment category once we all had experience with how unreliable they are.
I can't find the source anymore since 538 is no more, and I recall Nate even describing what could (and did) happen, which was that one swing state moving to the right had a high likelihood of them all moving to the right.
Yeah, Nate has talked a number of times about polling errors being correlated across states. In fact that's probably one of the most common mistakes models can make, treating correlated inputs as independent. There's a long history of that mistake in financial markets as well.
In 2024 the single most likely outcome his model had was trump winning all 7 swing states. The second most likely was Harris winning all 7.
Not just that, predictions also impact voter participation.
I think this is all true, but it dodges the bigger issue. A presidential election has a binary outcome: yes/no, win/lose. If your statistical model doesn’t contain this single bit in its output, then it doesn’t meet the minimum requirement for being a prediction.
Now you might say that it was on me as a consumer to understand this in 2016, but I remember the look of total shock on Nate Silver’s face when he called the winner on live TV that night, so clearly he didn’t really understand it either. Lesson learned for all of us, I guess.
It was 30% in the end, before the nomination it famously gave him a 2% chance of getting nominated. All the talk about 30% is disingenuous
https://en.wikipedia.org/wiki/FiveThirtyEight#2016_U.S._elec...
They had him at 30% at a time when most reputable media had him in single digits at best. You might not remember now, but the result of that election was a real shock.