538 Model Megathread

[twenty42]

Not to mention Silver had a 50.3% chance of Obama winning Florida in 2012. That's flipping a coin that it would take thousands of flips to determine is slightly weighted one way. In what sense was that a "call"?

Trump's very margin at this very moment in Florida.

[Sorenroy]

For some reason in their polls-plus model Ohio currently sits at a 46.3-46.2 Clinton win, but they have their odds of winning at 50.1-49.9 in favor of Trump.

[Sprouts Farmers Market ✘]

For the first time in forever, Trump has passed 40% in 538's polls-plus model.

Projected as the favorite in both Ohio and Florida. That doesn't make any sense.

[Ebsy]

For the first time in forever, Trump has passed 40% in 538's polls-plus model.

Projected as the favorite in both Ohio and Florida. That doesn't make any sense.

The model doesn't make any sense this far out.

[heatcharger]

For the first time in forever, Trump has passed 40% in 538's polls-plus model.

Projected as the favorite in both Ohio and Florida. That doesn't make any sense.

I think this model is too sensitive to trendlines for specific pollsters, namely Quinnipiac.

[Crumpets]

For the first time in forever, Trump has passed 40% in 538's polls-plus model.

Projected as the favorite in both Ohio and Florida. That doesn't make any sense.

I think this model is too sensitive to trendlines for specific pollsters, namely Quinnipiac.

I also don't get why they don't seem to have taken into account the convention bounce they projected. If Trump wants to be on track to get a 50-50 finish, he should probably be up a point or two in the swing states right now at least.

[Erich Maria Remarque]

For the first time in forever, Trump has passed 40% in 538's polls-plus model.

Projected as the favorite in both Ohio and Florida. That doesn't make any sense.

I think this model is too sensitive to trendlines for specific pollsters, namely Quinnipiac.

I also don't get why they don't seem to have taken into account the convention bounce they projected. If Trump wants to be on track to get a 50-50 finish, he should probably be up a point or two in the swing states right now at least.

But there were almost no polls after convention!

[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.

[Sprouts Farmers Market ✘]

For the first time in forever, Trump has passed 40% in 538's polls-plus model.

Projected as the favorite in both Ohio and Florida. That doesn't make any sense.

The model doesn't make any sense this far out.

Trump now projected as the favorite in Nevada!!! They're adjusting all polling in the wrong direction!

[Sir Mohamed]

For the first time in forever, Trump has passed 40% in 538's polls-plus model.

Projected as the favorite in both Ohio and Florida. That doesn't make any sense.

The model doesn't make any sense this far out.

Trump now projected as the favorite in Nevada!!! They're adjusting all polling in the wrong direction!

LOL. Same in NH.

[Erich Maria Remarque]

For the first time in forever, Trump has passed 40% in 538's polls-plus model.

Projected as the favorite in both Ohio and Florida. That doesn't make any sense.

The model doesn't make any sense this far out.

Trump now projected as the favorite in Nevada!!! They're adjusting all polling in the wrong direction!

Nate is fascist!

[The Other Castro]

He also has 57.5% chance of winning the presidency.

If it were held today.

[Seriously?]

For the first time in forever, Trump has passed 40% in 538's polls-plus model.

Projected as the favorite in both Ohio and Florida. That doesn't make any sense.

The model doesn't make any sense this far out.

Trump now projected as the favorite in Nevada!!! They're adjusting all polling in the wrong direction!

LOL. Same in NH.

Trump +3 nationally would do that to NV, OH, FL, NH, PA, probably IA, CO, VA etc., etc. etc. It's basic math.

Obama won by around 4.5% in 2008. Trump at +3 is a 7.5% swing. Those states would end up in the Trump camp.

[Gustaf]

Serious question - why does the Nowcast do a trendline? That doesn't make sense to me. If Clinton leads in Nevada now (as she does per their poll model) why would the Nowcast not predict her as ahead?

[afleitch]

Serious question - why does the Nowcast do a trendline? That doesn't make sense to me. If Clinton leads in Nevada now (as she does per their poll model) why would the Nowcast not predict her as ahead?

I've wondered that too. I also think he's launched his model too soon. There has been a relative drought in state polls in comparison to recent years. There's a poll from November in his model for Nevada. That shouldn't be there at this stage.

[emailking]

Serious question - why does the Nowcast do a trendline? That doesn't make sense to me. If Clinton leads in Nevada now (as she does per their poll model) why would the Nowcast not predict her as ahead?

Maybe I'm misunderstanding something, but the latest 5 it's showing have Trump up in 3 and Clinton up in 1. The most recent is Clinton +4, but it gets adjusted to a tie based on other factors (e.g. national polling, covariance with other states). So I guess it doesn't surprise me.

[Gustaf]

Serious question - why does the Nowcast do a trendline? That doesn't make sense to me. If Clinton leads in Nevada now (as she does per their poll model) why would the Nowcast not predict her as ahead?

Maybe I'm misunderstanding something, but the latest 5 it's showing have Trump up in 3 and Clinton up in 1. The most recent is Clinton +4, but it gets adjusted to a tie based on other factors (e.g. national polling, covariance with other states). So I guess it doesn't surprise me.

If you look at the Nevada Nowcast it has a polling average of Clinton +1.5%.

Adjustment for some of their stuff brings it to Clinton +1.2%.

THEN they adjust for "trend" which swings it by 4.5% in Trump's favour and gives it as Trump +3.4%.

I don't get what trend they're adjusting for if it's "election held today". The net swing is roughly the same as in the forecasts for November 8th.

[hopper]

I'll just go with the "Now Cast Model" and just look at that model on a daily basis which still has Hillary winning.

[Erc]

Serious question - why does the Nowcast do a trendline? That doesn't make sense to me. If Clinton leads in Nevada now (as she does per their poll model) why would the Nowcast not predict her as ahead?

Maybe I'm misunderstanding something, but the latest 5 it's showing have Trump up in 3 and Clinton up in 1. The most recent is Clinton +4, but it gets adjusted to a tie based on other factors (e.g. national polling, covariance with other states). So I guess it doesn't surprise me.

If you look at the Nevada Nowcast it has a polling average of Clinton +1.5%.

Adjustment for some of their stuff brings it to Clinton +1.2%.

THEN they adjust for "trend" which swings it by 4.5% in Trump's favour and gives it as Trump +3.4%.

I don't get what trend they're adjusting for if it's "election held today". The net swing is roughly the same as in the forecasts for November 8th.

Perhaps it's the fact that Trump has gained in recent national polling, and all of the polls are at least two weeks old?  Since Trump has gained nationally, you'd expect him to have gained in Nevada as well compared to the old polls.

It's amusing that the current polls-only forecast is the 269-269 tie, but there's something seriously wrong with any model that gives Trump a better than 1-in-3 chance of winning.

[Nym90]

Serious question - why does the Nowcast do a trendline? That doesn't make sense to me. If Clinton leads in Nevada now (as she does per their poll model) why would the Nowcast not predict her as ahead?

Maybe I'm misunderstanding something, but the latest 5 it's showing have Trump up in 3 and Clinton up in 1. The most recent is Clinton +4, but it gets adjusted to a tie based on other factors (e.g. national polling, covariance with other states). So I guess it doesn't surprise me.

If you look at the Nevada Nowcast it has a polling average of Clinton +1.5%.

Adjustment for some of their stuff brings it to Clinton +1.2%.

THEN they adjust for "trend" which swings it by 4.5% in Trump's favour and gives it as Trump +3.4%.

I don't get what trend they're adjusting for if it's "election held today". The net swing is roughly the same as in the forecasts for November 8th.

They are looking at how the national polls have changed since those Nevada state polls were conducted, and assuming Nevada has gone to the right at the same pace since then as the rest of the country (even though we don't have recent Nevada polls to confirm this).

[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.   

[Classic Conservative]

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.   

It did

[Wells]

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.   

It did

It doesn't. Only polls-plus does that.

[Mr. Morden]

Serious question - why does the Nowcast do a trendline? That doesn't make sense to me. If Clinton leads in Nevada now (as she does per their poll model) why would the Nowcast not predict her as ahead?

Maybe I'm misunderstanding something, but the latest 5 it's showing have Trump up in 3 and Clinton up in 1. The most recent is Clinton +4, but it gets adjusted to a tie based on other factors (e.g. national polling, covariance with other states). So I guess it doesn't surprise me.

If you look at the Nevada Nowcast it has a polling average of Clinton +1.5%.

Adjustment for some of their stuff brings it to Clinton +1.2%.

THEN they adjust for "trend" which swings it by 4.5% in Trump's favour and gives it as Trump +3.4%.

I don't get what trend they're adjusting for if it's "election held today". The net swing is roughly the same as in the forecasts for November 8th.

They are looking at how the national polls have changed since those Nevada state polls were conducted, and assuming Nevada has gone to the right at the same pace since then as the rest of the country (even though we don't have recent Nevada polls to confirm this).

Yeah, now-cast doesn't mean you take all the polls as is at the time they were taken.  It means you take the polls and adjust them for any trends in national polls that have happened since they were taken, to see what they would look like if taken right now.

[Gustaf]

Serious question - why does the Nowcast do a trendline? That doesn't make sense to me. If Clinton leads in Nevada now (as she does per their poll model) why would the Nowcast not predict her as ahead?

Maybe I'm misunderstanding something, but the latest 5 it's showing have Trump up in 3 and Clinton up in 1. The most recent is Clinton +4, but it gets adjusted to a tie based on other factors (e.g. national polling, covariance with other states). So I guess it doesn't surprise me.

If you look at the Nevada Nowcast it has a polling average of Clinton +1.5%.

Adjustment for some of their stuff brings it to Clinton +1.2%.

THEN they adjust for "trend" which swings it by 4.5% in Trump's favour and gives it as Trump +3.4%.

I don't get what trend they're adjusting for if it's "election held today". The net swing is roughly the same as in the forecasts for November 8th.

They are looking at how the national polls have changed since those Nevada state polls were conducted, and assuming Nevada has gone to the right at the same pace since then as the rest of the country (even though we don't have recent Nevada polls to confirm this).

Yeah, now-cast doesn't mean you take all the polls as is at the time they were taken.  It means you take the polls and adjust them for any trends in national polls that have happened since they were taken, to see what they would look like if taken right now.

I thought about that but then why are the trends not a lot stronger for the November forecasts? It's cancelled out by the polls themselves being valued less?