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Answers to your questions about polling and elections.

1. David Callaway writes:

I read elsewhere (Kevin Drum) that the response rate to telephone polling is around 5%. It seems to me that means you are no longer dealing with a random sample, what you have instead is a self selected pool. I understand that to an extent you can correct a model for data problems, but 5% response? How do you know what to correct for? Take another poll to determine what errors to correct for and how much? Use the time honored “listen to my gut” method?

Instead of going to a lot of trouble to gin up a random list sized to leave an adequate-sounding sample after 95% hangups pollsters might instead be honest and just say the current polling methods don’t return usable data, take their ball and go home.

My reply: I’ve heard that the response rate is closer to 1% than to 5%. As to your question of whether pollsters should just “go home” . . . I don’t think so! This is their business. And, hey, the polls were off by about 2.5 percentage points on average. For most applications, that’s not bad at all. I do feel that we have too many polls, but you have to remember that the main economic motivation for polls is not the horse-race questions. Those are just the way that pollsters get attention. They make their money by asking questions for businesses. And if you’re a business trying to learn what percentage of people have heard of your product or whatever, then an error of 2.5 percentage points is not bad at all.

Also, if pollsters were all gonna quit just because their polls are off by more than their stated margin of error, then they should’ve already quit years ago.

2. Another person writes:

I respectfully suggest that you owe it to readers of The Economist (and others) to comment on how you figure it is that your forecasting model erred so badly re the electoral count and the popular vote for the presidency as well.

For a quick answer, we forecast Biden to receive between 259-415 electoral votes and it seems that he’ll end up with about 300, so I wouldn’t say the model “erred so badly.” Similarly for the popular vote. But there were some issues, which we discuss here and here. I do think our model had problems, but there’s a big difference between having problems and “erred so badly.” If you think that what happened was “erred so badly,” I think the problem is that your expectation is too high: the point of the wide uncertainty interval is that our model can’t make a precise prediction.

3. Ricardo Vieira asks what I think about this post, which stated:

Over this and past USA presidential elections my memory says that many states have been won by <<1% between the major parties. I've heard it suggested that this is due to parties modifying their platforms to appeal to just enough voters to win in relevant swing states. It makes sense that they try to rebalance this way, but as a mechanism for the near perfect splits we often observe it is insufficient. If any party had the techniques to know where 50% appeal is, pollsters would too, so we'd also have much more accurate polls. And the "omniscience party" would surely give themselves enough cushion to rarely ever lose. The alternate explanation is chance, i.e.: the results of each state's election are a random sampling over the distribution of possible % splits; in our age the mean of that distribution happens to have shifted to be near 50%; and the "swing states" are those that fall very close to the mean and are thus often decided by <<1%. That's fine in principle, but some of the margins are mind-bogglingly small. The most notable example is Florida in 2000 (wikipedia):

After an intense recount process and the United States Supreme Court’s decision in Bush v. Gore, Bush won Florida’s electoral votes by a margin of only 537 votes out of almost six million cast and, as a result, became the president-elect.

Georgia this year is currently <1500 votes difference (<.1%) with >99% votes counted. PA probably won’t be that close in the end but it’s still gonna pretty damn close, within a few tenths of a point.

Having grown up in this era and never having been a student of political science, how normal is this? Can anyone link a study where folks have looked at the distributions and shown how likely it is for a vote to be decided by 1k or less margins this frequently over 50 states?

Actually Gore won Florida by 30,000 votes, or he would have

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