538 Model Megathread

[jaichind]

With some of the post-convention bounce polls in, Now Cast has Trump's chances at 57.5%. This plus a bit more as more post-convention bounce polls comes in will most likely be the Trump peak for Now Cast chances for this election.  Polls-plus which I prefer more still has Trump's chances at 41.7% which mostly fit in with how I see the race.

[jaichind]

I am surprised the Nov Polls-only forecast has Trump's chances at 47%.   I would imagine the model takes into account the temporary GOP post-convention bounce.   

[jaichind]

Trump changes on poll-plus approaching levels at the peak of the RNC.

[jaichind]

538 inputed a WV poll incorrectly. It has a Just Win poll with Clinton +27 when it should be Trump +27.  What a bizarre mistake to make.

[jaichind]

Odd... you'd think they'd have scripts to automate those things.

How would such a script work?  Search through the PDF of the poll release for the Clinton and Trump numbers?  When every pollster will have poll releases that look different?  It's a lot easier to just type in the numbers manually.

I was more thinking as one manually enters the numbers and they are off the average by, say, 10%, a popup windows comes up saying "a you sure about that" 

[jaichind]

I don't agree with his odds in swing states and if they are correct then Clinton has a much better chance of winning than he says she does.  Today's map agrees with the overall consensus 273-265 and if her chances are as high in states like PA, VA, CO and NH as he says they are she has more than a 58.1% chance of winning. NH is more likely to go Clinton than CO or VA and PA has a better chance than VA. I do think he's right about the overall odds, although they may be even better, unless, as could happen, Trump improves in the next few weeks,  he could even be tied or ahead, which so far hasn't happened yet. NV, FL and other states are closer to 50-50. IA an AZ should be higher. Overall he might be close, but some states are off. IA is the worst prediction although Trump may be above 50% and he could certainly win there, even though it has been pretty reliable for Dems (except, of course 2004).

edit, however all predictions are open to debate because this election is very unpredictable (IA being a good example, because Clinton could still win there). He might be right about NV being the closest, however.

All things equal I agree with you.  I think the model has a much lower correlation factor between results of places like PA VA NH and CO.  If Clinton comes out ahead in one of them then most likely she will win all 4.  In that sense the real chances of a Trump victory should really be in the mid 30s and not above 40%.  On the other hand these numbers does imply that the chances of Trump coming close to winning but not winning will be quite large. 

[jaichind]

The 538 senate model has also moved over to GOP for Senate control.  Part of it has to do with the fact that 50-50 will be more likely mean GOP control given Trump's chances has surged.  But most of it is just polls moving in GOP direction in the Senate races.

[jaichind]

Looks like 538 entered the latest NM poll incorrectly.  They have it 45 31 24 when it should be 35 31 25.  The Clinton lead is 4 and not 14.

[jaichind]

What is interesting is if you take the Oct 30 538 Trump chances for polls-plus and now-cast it comes out to 23.0% and 22.3% respectively.  In 2012 the Oct 28 (same number of days to election day) Romney chances for the 538 prediction model and the now-cast model comes out to 26.4% and 19.9%.  So at the same point in the campaign Romney and Trump have roughly the same chances of victory. Of course this seems to reflect a greater volatility in the 2016 election.  On the other hand Obama clearly had the momentum the last two weeks of the election whereas Trump seems to have the momentum in the closing days of the election this time around. 

[jaichind]

Trump's chances in Now-cast above 25% and the highest since late Sept.  He pretty much erased all the losses from Pussygate and part of the losses from the first debate. Next few days will see if he can get to the level before the first debate.  If so he has a shot.  If not he will still fall short election day.

[jaichind]

Nowcast has NV FL NC OH IA all leaning Trump.  Some by the narrowest of margins of course.

[jaichind]

For Polls plus the addition of the AZ Saguaro Strategies poll which had Clinton +1 which got adjusted to Trump +1 actually increased Trump's chances from 34.1 to 34.4 which seems bizarre to me given where Trump should be for AZ.  Only reason I can think of is that this poll is slight more positive for Trump than the prev Saguaro Strategies poll had Clinton +2.

[jaichind]

NV leaning Trump on all 3 models again.   Trump ahead in NV FL NC by low 50's percentages in all three models right now.

[jaichind]

Nate is an awful spot here. If Hillary wins, he'll look bad because he was so bullish on Trump relative to the other forecasters. But even if Trump wins he'll get no credit, since he still has Hillary as a (very) modest favorite.

Hopefully Tuesday will spell the end of the discredited fraud's career.

Well, if Clinton wins narrowly with PV spread of around 1%-2% then Nate would look pretty good.

[jaichind]

All 3 models now have NV for Clinton, FL NC and ME2 for Trump.  This matches my prediction exactly.

[jaichind]

The current models seems to have Clinton's lead at 3% which seems to match the medium of the national polls.  So if this site is off then it is more because of how it distributes the votes and not absolute   vote share.  I personally believe Clinton's lead is likely to be less than 3% and have a more Trump friendly distribution than 538.   

[jaichind]

The 538 error map seems highly correlated to the trend map by county.

Trend:

[jaichind]

The lesson to be learned here is to never trust Nate Silver ever again.

Why? He came closer the pretty much all other models.