@FiveThirtyEight What makes this really powerful is that it incorporates correlated errors. Biden is ahead in the polls in PA, so if Trump wins it, that means the polls were off (or that something else changed). That shifts probabilities elsewhere as well, esp. nearby states like Ohio.

@bencasselman @FiveThirtyEight If I understand this correctly, the outcomes are correlated. So choosing Trump to win PA increases his odds of winning other states. It’s the correct model IMO but changes the interpretation.

@danielmangrum @FiveThirtyEight Yes, that's right. The polls favor Biden in PA, so if Trump wins it, that indicates the polls were off there (or something changed in the real world), so probabilities in other states shift as well. (With some states correlated more strongly with PA than others.)

@bencasselman @FiveThirtyEight You've not understood the model - by giving Trump or Biden PA the other states' results are affected, as you can see on the screenshots

@AScribbledEagle @FiveThirtyEight Right. The model (correctly) recognizes that results are correlated. If Trump wins PA, that means the polls there were off (or something changed), so that means other states will probably swing in his direction as well.

@bencasselman @FiveThirtyEight Ben that's not totally accurate . It also depends on what other swing states you project dump to win or lose .

@dumpchrump @FiveThirtyEight Well, but the example I showed was assuming you make no other selection, and it updates its probabilities based on how you assign PA.

@bencasselman @FiveThirtyEight I am feeling increasing optimistic that if Trump wins PA, Biden can make up for with NC and AZ.

@bencasselman @FiveThirtyEight Their biggest problem is still that common folks don't trust the polls to be right. Sure Nate got it 2 prez elections in a row, but basically he saying "our models say 9 out of the 10 invitees to your dinner party aren't axe murderer of democracy" but if it happens... He still $

@bencasselman @FiveThirtyEight Stop doing this to us, I’m telling you we are at maximum freakout level here in PA already!!

@bencasselman @FiveThirtyEight Polls are nothing. JUST VOTE.

@bencasselman @FiveThirtyEight He doesn't want it.

@bencasselman @FiveThirtyEight Just sayin but Biden prob won’t win North Carolina

@bencasselman @FiveThirtyEight Excellent. Now I can play out all my doom scenarios today.

@bencasselman @BrandenHarvey @FiveThirtyEight Surprising that tossup states have a large effect on model predictions for other states. E.g., calling Ohio (predicted 50/50) should change outcome distribution (locks in EVs), but absent data on margin of victory, outcome of Ohio doesn't provide much information abt other states

@bencasselman @FiveThirtyEight Interesting. If you give Trump PA , but lock in CO, MN and MI for Joe...it’s basically 50-50.

@bencasselman @FiveThirtyEight @GandhiSanjay68 @r_s_gandhi @AvaniGandhi11 keep that phone banking going!

@bencasselman @FiveThirtyEight Same with Wisconsin. And both don’t start counting mail in ballots until Election Day...