538 Model Megathread

[100% pro-life no matter what]

One more good poll could put Trump above 25 in polls-plus and the nowcast (he is at 24.2 in both).

[muon2]

If you use HuffPo 3-way and limit the polls to nonpartisan pollsters and likely voters the current numbers from their trend lines are Clinton 45.1%, Trump 40.7%, Johnson 5.1%. For the 2-way it gives 45.8% to 42.4% (moderate smoothing)

Why would you do any of this?

This in response to posts on both sides complaining about inclusion of partisan pollsters. HuffPo lets me filter them out so I did this as a point of comparison.

By further comparison that same exercise today has Clinton 45.2%, Trump 42.5%, Johnson 4.9% in the 3-way and Clinton 45.4% to 42.8%  in the 2-way. Clinton's share in both is essentially unchanged from my post 4 days ago.

[Blackacre]

If you use HuffPo 3-way and limit the polls to nonpartisan pollsters and likely voters the current numbers from their trend lines are Clinton 45.1%, Trump 40.7%, Johnson 5.1%. For the 2-way it gives 45.8% to 42.4% (moderate smoothing)

Why would you do any of this?

This in response to posts on both sides complaining about inclusion of partisan pollsters. HuffPo lets me filter them out so I did this as a point of comparison.

By further comparison that same exercise today has Clinton 45.2%, Trump 42.5%, Johnson 4.9% in the 3-way and Clinton 45.4% to 42.8%  in the 2-way. Clinton's share in both is essentially unchanged from my post 4 days ago.

HuffPo lets you do that?  How?

[Mr. Morden]

If you use HuffPo 3-way and limit the polls to nonpartisan pollsters and likely voters the current numbers from their trend lines are Clinton 45.1%, Trump 40.7%, Johnson 5.1%. For the 2-way it gives 45.8% to 42.4% (moderate smoothing)

Why would you do any of this?

This in response to posts on both sides complaining about inclusion of partisan pollsters. HuffPo lets me filter them out so I did this as a point of comparison.

By further comparison that same exercise today has Clinton 45.2%, Trump 42.5%, Johnson 4.9% in the 3-way and Clinton 45.4% to 42.8%  in the 2-way. Clinton's share in both is essentially unchanged from my post 4 days ago.

HuffPo lets you do that?  How?

At the top of the page, click on "customize this chart", and you can select which pollsters you want to include, as well as how much smoothing to use.

[Mr. Morden]

Incidentally, I hadn't noticed previously that HuffPo also allows you to view the polling trendlines among just Dems, just Republicans, and just Indies.

I just compared them, and they showed what I'd been noticing anecdotally in the individual polls: Trump isn't gaining ground among Republicans.  His gains have come from Independents instead.  As the 3rd party vote share has declined, Clinton's gained ground with Dems and Trump has gained ground with Indies.  But Republicans have remained flat, with Trump pulling ~80% of them, compared to Clinton getting ~86% of Dems.  Since Oct. 2, for example, this is the change in support from each party group, using moderate smoothing:

Dems
Clinton +2.9
Trump -1.1
Johnson -0.3

GOP
Clinton no change
Trump -0.2
Johnson -0.9

Indies
Clinton -0.7
Trump +1.9
Johnson -1.5

Link to the charts:

Democrats

Republicans

Independents

[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.

[Erich Maria Remarque]

In now-cast Trump has better chances to win the presidency than Republicans the Senate...

[100% pro-life no matter what]

Florida flips to Trump in polls plus

[Middle-aged Europe]

Last Friday, Nate Silver estimated/predicted that Hillary could drop to 68% in the polls-only model due to Comey-gate. We're at 74% now.

[Erich Maria Remarque]

Poll-plus model.

Last Friday, Nate Silver estimated/predicted that Hillary could drop to 68% in the polls-only model due to Comey-gate. We're at 74% now.

You must be logged in to read this quote.

So Comey [or not] almost cost Clinton 2% points. So far.

[Beefalow and the Consumer]

Poll-plus model.

Last Friday, Nate Silver estimated/predicted that Hillary could drop to 68% in the polls-only model due to Comey-gate. We're at 74% now.

You must be logged in to read this quote.

So Comey [or not] almost cost Clinton 2% points. So far.

Polls-plus is garbage.

[Confused Democrat]

Do we generally view Nate's model as more reliable than the others?

[Blackacre]

Look at that trendline, though. It looks like it's forming a circle, and that's honestly terrifying.

[Erich Maria Remarque]

Polls-plus is garbage.

It is not like there is a big difference. I usually don't post Polls-plus, but they were first to reach this beauriful number, so I made an exception. Sorry, I won't do it from now on

[The Other Castro]

Do we generally view Nate's model as more reliable than the others?

Garbage in, garbage out is how I'm viewing his model right now.

[BoAtlantis]

Do we generally view Nate's model as more reliable than the others?

Silver gets more publicity because his site is more decorated. Drew Linzer of Daily Kos and Sam Wang of Princeton Consortium were more accurate in 2012.

http://rationality.org/2012/11/09/was-nate-silver-the-most-accurate-2012-election-pundit/

Drew Linzer   0.00384
Wang & Ferguson   0.00761
Nate Silver   0.00911
Simon Jackman   0.00971
DeSart & Holbrook   0.01605
Intrade   0.02812
2008 Repeat   0.03922
Margin of Error   0.05075
Coin Flip   0.25000

That doesn't translate to future performance. Sam Wang did way worse in 2014 but that was midterm in which Democrats don't tend to turn out.

Sam Wang also only uses polls and mean-revert whereas Silver uses his own special sauce like the economy, endorsements etc.

[Erich Maria Remarque]

Do we generally view Nate's model as more reliable than the others?

Garbage in, garbage out is how I'm viewing his model right now.

It is certainly a coincidence, but my analysis shows that your garbagemometer is highly correlated with Trump's chances to win.

[Speed of Sound]

While we're comparing the two, I'll admit that I'm a tad shocked that Wang's model hasn't back off at all. Still 97 random/99 Bayesian, as it was a week ago. I thought it might revert a bit, but not so far.

[Confused Democrat]

Do we generally view Nate's model as more reliable than the others?

Silver gets more publicity because his site is more decorated. Drew Linzer of Daily Kos and Sam Wang of Princeton Consortium were more accurate in 2012.

http://rationality.org/2012/11/09/was-nate-silver-the-most-accurate-2012-election-pundit/

Drew Linzer   0.00384
Wang & Ferguson   0.00761
Nate Silver   0.00911
Simon Jackman   0.00971
DeSart & Holbrook   0.01605
Intrade   0.02812
2008 Repeat   0.03922
Margin of Error   0.05075
Coin Flip   0.25000

That doesn't translate to future performance. Sam Wang did way worse in 2014 but that was midterm in which Democrats don't tend to turn out.

Sam Wang also only uses polls and mean-revert whereas Silver uses his own special sauce like the economy, endorsements etc.

Didn't Wang get his Florida prediction wrong in 2012?

[Speed of Sound]

Didn't Wang get his Florida prediction wrong in 2012?

Technically, yes, but not really:

You must be logged in to read this quote.

[Slander and/or Libel]

Silver essentially called Florida a coin flip in 2012. He had it at 50.3% for Obama. It is not in any meaningful sense a "call" that was "correct", nor would it have been wrong had Romney won Florida.

[Erich Maria Remarque]

Why do we always have this discussion, when Donald J Trump has a good week? Correlation?

[100% pro-life no matter what]

While we're comparing the two, I'll admit that I'm a tad shocked that Wang's model hasn't back off at all. Still 97 random/99 Bayesian, as it was a week ago. I thought it might revert a bit, but not so far.

Wang's model has insanely small confidence levels.  Didn't he have the Dems as like 90% favorites to maintain the Senate for most of 2014, but flipped it a few days before the elections?

[Speed of Sound]

While we're comparing the two, I'll admit that I'm a tad shocked that Wang's model hasn't back off at all. Still 97 random/99 Bayesian, as it was a week ago. I thought it might revert a bit, but not so far.

Wang's model has insanely small confidence levels.  Didn't he have the Dems as like 90% favorites to maintain the Senate for most of 2014, but flipped it a few days before the elections?

Maybe true, but he hasn't moved below 95% on this election in eons.

[Slander and/or Libel]

While we're comparing the two, I'll admit that I'm a tad shocked that Wang's model hasn't back off at all. Still 97 random/99 Bayesian, as it was a week ago. I thought it might revert a bit, but not so far.

Wang's model has insanely small confidence levels.  Didn't he have the Dems as like 90% favorites to maintain the Senate for most of 2014, but flipped it a few days before the elections?

As I recall, his model was way optimistic for the Democrats right through the elections. He's gone into a good bit of detail about where the failures were in 2014 and what he's done to address them.