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But that’s simply not true. Because Florida and Texas alone were so far off, 10% odds was definitely “way” wrong. Nate’s model predicted that if Florida went Tr

But that’s simply not true. Because Florida and Texas alone were so far off, 10% odds was definitely “way” wrong. Nate’s model predicted that if Florida went Trump the odds were at 33% or so. Texas moreso, etc. Since Florida went incredibly strongly Trump, we can say with certainty he was completely wrong on the 10% chance. That’s the point: he was way overconfident his past model would fit, it should have been closer to a slightly advantage, which would read something like 60/40 at best.

awb 6y ago
> Since Florida went incredibly strongly Trump, we can say with certainty he was completely wrong on the 10% chance. The model generated 40k scenarios, and the scenario you're describing is one of them. The most extreme scenarios have Trump winning all swing states by a few %, which doesn't look likely. So what's playing out is not wildly outside the predictions by any means. In other words, if a 10% chance happens, it doesn't mean the 10% prediction was wrong. The only way to prove a prediction was wrong is to bet against it over time with your own predictions. As Silver has shown there's a huge appetite for election / sports predictions. Anyone able to beat him over time would have enormous income potential. For example, if you thought Trump had at least a 40% chance to win, you'd have a great betting opportunity in the market that had Trump in the 25-33% range. You could have bought in then and sold when Trump's chance peaked at about 50-60%. If you arbitrage those mistakes you've identified in the market, overtime you could become very wealthy. Until then, it's just pundits pontificating after the results are known without putting any money or reputation on the line beforehand, similar to a casual sports fan late in the 4th quarter: "of course the 49ers were going to blow their lead -- I just knew it!"
- nwienert 6y ago
  His probability of Florida being won by that much was basically 0. But it was actually almost the opposite, in the real world the probability of Biden winning was almost 0. The polls were so far off systematically in one direction - it doesn’t mean he was right about the 10% chance, because that would mean there was equally likely a chance they were all off in the other direction, which is obviously just wrong. Polling missed huge groups of voters opinions - it was just wrong. We have numbers now that show that Trump voters also aren’t forthcoming on their vote. Probably on purpose as an effect of last election and being spiteful towards pollsters in general. I actually had this as a strong prior, so my model predicted this would be close, but of course if you “just go by the polls” you’re essentially trusting a flawed system that is gameable. Anyone who trusts the polls is essentially a fool next time, they have been shown to be incorrect now twice in large amounts and I wouldn’t doubt that the “meme” the right has started to purposely deceive them continues even after Trump. You are absolutely wrong on your 49ers analogy and the 10% covering this. Florida disproves it, as do the systemic nature of being off. If they weren’t off systematically, you’d have expected the polls to get Florida wrong one direction but other states wrong in a different direction. That would prove the model, but if every single state was multiple points off all in the same direction, you don’t get to call margin of error. Your bell curve was shifted one direction, it wasn’t a case of the curve being right but the dice rolled in the tail.
  - awb 6y ago
    Yes, some states had big polling errors, while others like GA and AZ were reasonably accurate. But the model doesn't care if the polls are off in FL by 0.1% or 10% because it's a winner take all scenario. So while large polling errors are surprising, they have the same exact impact as a small polling error in a close race, which isn't surprising. But people like to cherry pick and say "how did you get X so wrong?" rather than "how did you get X/10 so right?" In fact, Trump might only end up winning 3 "upsets": FL, NC and ME-2, but they were all under 2% difference in the polls, so no one is shocked to see Trump win there. WI and MI would have been much bigger upsets, but that didn't end up happening and a 20k vote win is as good as a 2M vote win in the EC. The 10% odds come from the path to 270. Here are the 9 states / districts that polled within 2% pre-election (considered toss ups): NE-2, AZ, FL, NC, ME-2, GA, OH, IA, TX. Even if Trump won all of those, he wouldn't get to 270. Using 50/50 odds for all 9 toss ups, Trump only gets a clean sweep 11% of the time. He would then still need another state like PA, WI or MI to get to 270. That's why Silver said that Biden's chances are so high, specifically because Biden could overcome a 2016-level polling error in every toss-up state and still win. In fact we saw 2016-level polling errors in some battleground states, but not all. Another way to view it, is you have a 1/6 (16%) chance of rolling a 1 on a 6-sided die. Even if all 53 states and districts were projected at 84% confidence, and rolling a 1 meant "upset" and rolling 2-6 meant "polls were accurate", you'd end up with 8-9 states resulting in upsets! 84% confidence still means a lot of surprises. Their final FL prediction was only 69% confidence. Also, confidence intervals aren't linear, meaning that a 95% confidence anticipates half as many upsets as a 90% confidence interval. That +5% means -50% upsets, so 69 or 84% confidence is really not as sure a thing as it might sound. So, yes it's worth re-examining why polling was very accurate in AZ & GA but very off in TX & FL (specifically Latino's in Miami). But a 10% chance was not crazy IMO given how easy it was for Biden to overcome even huge polling / vote disparities in multiple states and still win. Again, those who disagree are free to get great odds in the betting markets.
    - nwienert 6y ago
      Bringing in betting markets has nothing to do with the point, but you are right on one thing: if you had bet along with Nate’s odds in a simulation you’d lose money in a Monte Carlo simulator based on current results. The end story is the polls weren’t a reliable measure of the vote. Their predictive ability was low, and even playing by the rules of Nate’s model you have to admit he was off by some 30% at minimum. Nate’s model has the average PA poll at Biden +6 (!!) where the final result looks to be under 1 (and could go either way). It’s simply impossible to argue that was an accurate model.

awb 6y ago

> Since Florida went incredibly strongly Trump, we can say with certainty he was completely wrong on the 10% chance. The model generated 40k scenarios, and the scenario you're describing is one of them. The most extreme scenarios have Trump winning all swing states by a few %, which doesn't look likely. So what's playing out is not wildly outside the predictions by any means. In other words, if a 10% chance happens, it doesn't mean the 10% prediction was wrong. The only way to prove a prediction was wrong is to bet against it over time with your own predictions. As Silver has shown there's a huge appetite for election / sports predictions. Anyone able to beat him over time would have enormous income potential. For example, if you thought Trump had at least a 40% chance to win, you'd have a great betting opportunity in the market that had Trump in the 25-33% range. You could have bought in then and sold when Trump's chance peaked at about 50-60%. If you arbitrage those mistakes you've identified in the market, overtime you could become very wealthy. Until then, it's just pundits pontificating after the results are known without putting any money or reputation on the line beforehand, similar to a casual sports fan late in the 4th quarter: "of course the 49ers were going to blow their lead -- I just knew it!"

nwienert 6y ago
His probability of Florida being won by that much was basically 0. But it was actually almost the opposite, in the real world the probability of Biden winning was almost 0. The polls were so far off systematically in one direction - it doesn’t mean he was right about the 10% chance, because that would mean there was equally likely a chance they were all off in the other direction, which is obviously just wrong. Polling missed huge groups of voters opinions - it was just wrong. We have numbers now that show that Trump voters also aren’t forthcoming on their vote. Probably on purpose as an effect of last election and being spiteful towards pollsters in general. I actually had this as a strong prior, so my model predicted this would be close, but of course if you “just go by the polls” you’re essentially trusting a flawed system that is gameable. Anyone who trusts the polls is essentially a fool next time, they have been shown to be incorrect now twice in large amounts and I wouldn’t doubt that the “meme” the right has started to purposely deceive them continues even after Trump. You are absolutely wrong on your 49ers analogy and the 10% covering this. Florida disproves it, as do the systemic nature of being off. If they weren’t off systematically, you’d have expected the polls to get Florida wrong one direction but other states wrong in a different direction. That would prove the model, but if every single state was multiple points off all in the same direction, you don’t get to call margin of error. Your bell curve was shifted one direction, it wasn’t a case of the curve being right but the dice rolled in the tail.
- awb 6y ago
  Yes, some states had big polling errors, while others like GA and AZ were reasonably accurate. But the model doesn't care if the polls are off in FL by 0.1% or 10% because it's a winner take all scenario. So while large polling errors are surprising, they have the same exact impact as a small polling error in a close race, which isn't surprising. But people like to cherry pick and say "how did you get X so wrong?" rather than "how did you get X/10 so right?" In fact, Trump might only end up winning 3 "upsets": FL, NC and ME-2, but they were all under 2% difference in the polls, so no one is shocked to see Trump win there. WI and MI would have been much bigger upsets, but that didn't end up happening and a 20k vote win is as good as a 2M vote win in the EC. The 10% odds come from the path to 270. Here are the 9 states / districts that polled within 2% pre-election (considered toss ups): NE-2, AZ, FL, NC, ME-2, GA, OH, IA, TX. Even if Trump won all of those, he wouldn't get to 270. Using 50/50 odds for all 9 toss ups, Trump only gets a clean sweep 11% of the time. He would then still need another state like PA, WI or MI to get to 270. That's why Silver said that Biden's chances are so high, specifically because Biden could overcome a 2016-level polling error in every toss-up state and still win. In fact we saw 2016-level polling errors in some battleground states, but not all. Another way to view it, is you have a 1/6 (16%) chance of rolling a 1 on a 6-sided die. Even if all 53 states and districts were projected at 84% confidence, and rolling a 1 meant "upset" and rolling 2-6 meant "polls were accurate", you'd end up with 8-9 states resulting in upsets! 84% confidence still means a lot of surprises. Their final FL prediction was only 69% confidence. Also, confidence intervals aren't linear, meaning that a 95% confidence anticipates half as many upsets as a 90% confidence interval. That +5% means -50% upsets, so 69 or 84% confidence is really not as sure a thing as it might sound. So, yes it's worth re-examining why polling was very accurate in AZ & GA but very off in TX & FL (specifically Latino's in Miami). But a 10% chance was not crazy IMO given how easy it was for Biden to overcome even huge polling / vote disparities in multiple states and still win. Again, those who disagree are free to get great odds in the betting markets.
  - nwienert 6y ago
    Bringing in betting markets has nothing to do with the point, but you are right on one thing: if you had bet along with Nate’s odds in a simulation you’d lose money in a Monte Carlo simulator based on current results. The end story is the polls weren’t a reliable measure of the vote. Their predictive ability was low, and even playing by the rules of Nate’s model you have to admit he was off by some 30% at minimum. Nate’s model has the average PA poll at Biden +6 (!!) where the final result looks to be under 1 (and could go either way). It’s simply impossible to argue that was an accurate model.