538 model & poll tracker thread

[Antonio the Sixth]

I've noticed that whenever there's a rounding area causing the percentages to add up to 99 instead of 100, they include a tied map in their 100 randomly selected maps. Seems a little misleading.

Isn't a tied map the only reason the %'s wouldn't add up to 100?

I assume that the model isn't literally taking 100 random maps from among all the maps.  If Biden is projected to win 77% of the time, it must always choose exactly 77 maps where Biden is projected to win.  Otherwise, the composition of this sample would fluctuate enormously, as the margin of error for a sample of 100 is around 10%.

Given this, is seems reasonable to deliberately choose exactly one tied map when the tie possibility makes a meaningful difference in the percentages.

Technically yes, but just because the numbers currently don't add up to 100 doesn't mean that the odds of a tie have increased.

And yeah, they are deliberately choosing a number of maps that reflects the current percentage for each candidate. I'm not sure how the algorithm for that works though.

Well, they estimate the probability of a tie to be around 0.5%, so if you're using 100 dots it seems fair to include it about half the time.

[Antonio the Sixth]

This model has become completely perplexing to me. 

On Sept. 19, 11 days ago, Biden was 77% to win.
During the past 11 days, the following things have happened:
1.) Biden’s national lead has grown a full percentage point, from 6.6 to 7.6
2.) There have been three A or A+ quality polls of the tipping point state (PA) suggesting Biden is winning the state by more than his national lead
3.) The election has gone from being 45 days away to 34 days away, which should substantially reduce uncertainty.

And yet Biden’s win % has only increases a single point, to 78%.
How is this possible?  What is actually necessary to move the needle?

The main issue seems to be that Biden was being artificially propped up because the model thought the RNC convention bounce was still going on at that point (kind of weird that they modeled such a long convention bounce, but I guess they're basing themselves off previous cycles when this stuff had more of an impact). Now, that bounce adjustment has almost entirely worn off, which has had the effect of blunting Biden's gains.

Even then, these gains are far from uniform. He's continued to get bad polls in FL, NC and AZ, which while not the most likely tipping points, would be a major freiwall for Biden if he could pull away there.

[Antonio the Sixth]

He said in the aritcle that went up last night that Biden's odds would be 91% on Election Day if things stay consistent.

Given that 91% was exactly the odds he gave Obama 2012 on Election Day when Obama only had a 1.5% national polling average lead over Romney, it says a lot about how much more cautious this model is that it'd give Biden's much larger lead the same chance.

Obama had an electoral college advantage of about 2 points. Biden has an electoral college disadvantage of about 2 points. Adjust for that and the numbers are pretty comparable.

[Antonio the Sixth]

"Model that's explicitly polls-driven is reliant on polls (shocking!) and therefore affected by polling issues" is not a damning criticism. That's just the constraint inherent in the exercise.

You know, it's really telling how people are incapable to simply levy empirical criticism at the 538 model and try to analyze their roots and potential fixes that could be applied, but instead just go off on unhinged rants about how terrible he is and how Nate Silver is a disgusting fraud (by... building a statistical model with a perfectly transparent methodology and being extremely open about its limitations). That suggests pretty deep insecurities if you ask me.

[Antonio the Sixth]

When will the "Economics & incumbency" caveat start to fade? Was it expecting a much better jobs report that wouldn't be overshadowed by the President being hospitalized?

It's the only metric preventing Georgia from being 50/50 on the model

It's already fading pretty fast. It's only weighted around 10% of the forecast in most well-polled states, compared to around 20% a few weeks ago.

[Antonio the Sixth]

When will the "Economics & incumbency" caveat start to fade? Was it expecting a much better jobs report that wouldn't be overshadowed by the President being hospitalized?

It's the only metric preventing Georgia from being 50/50 on the model

It's already fading pretty fast. It's only weighted around 10% of the forecast in most well-polled states, compared to around 20% a few weeks ago.

Feels like it's been around 13% in the closer states for over a week

I seem to remember it was over 15% until a few days ago, and now it's below in most swing states. Also note there haven't been many state polls in the past couple days (we got a lot of national polls but those don't really affect the calculation).

Also, the jobs report did significantly alter the fundamentals forecast in Biden's direction. Prior to it, it had him down in PA by like 7 points, now just 2 points.

[Antonio the Sixth]

Fivey Fox is cringy as hell but the parodies are cringier.