Demographics and the Electorate

[Erc]

(snip)
I don't suppose anyone with a lot of time on their hands would be willing to go through all the national polls one by one to see if they have crosstab info on the %age of the sample with college degrees, and then we could look at whether there's really a systematic deviation from what we would expect?  Also could see if there's a strong correlation between the %age of the sample that has college degrees and the overall support for Clinton.

Thinking about this a bit harder, the abormally low percentage of people with college degrees in these polls is weird, but it's not going to affect the top line that much.

If I'm dialing the turnout of just white RVs with college degrees, this is a group of people that is voting pretty similar to the rest of the country (in aggregate).  Clinton has consistently had a solid lead (5-12 points or so) among these voters, which is pretty similar, in the grand scheme of things, to the polling as a whole, where Clinton has consistently had a lead of 1-6 points. You can decrease white college turnout by 50%, and not really affect the national numbers by more than about a percentage point.

What really matters, in terms of turnout, are the actually polarized groups: white voters without a bachelor's degree (favoring Trump about 2-to-1) and non-white voters (favoring Clinton by at least 4-to-1).

So, the $64,000 question is: in the final voting electorate, what's the ratio of non-college white voters to all non-white voters?

The latest ABC-WaPo poll has that ratio at 163%.
538's demographic calculator (as an extrapolation from 2012) has that ratio at 113%.

That's a big difference.  Is non-white turnout really going to decrease by more than a few points (if that)?  If not, is non-college white turnout really going up by 44%?  (That would require something like an 81% total turnout among non-college white voters, which seems insanely large.  Turnout hasn't been anywhere near such levels since the 19th century.)

Even that 163% figure, plugging it into the calculator, still gives a 4-point Clinton win even if every single white college-educated voter stays home.

[Erc]

FiveThirtyEight has updated its calculators, which has a pretty significant bearing on this discussion.

A point I alluded to briefly earlier in this thread was the large difference between exit polling and census data when it comes to what share of voters have a college degree.  The previous version of the calculator largely used exit polls (47% in 2012), while census data showed 37%.  This is a big discrepancy, and I was (perhaps unfairly) questioning the reality of polls that more closely matched the latter number.

This is not a question that's mattered that much in previous elections, as (controlling for race) education didn't matter all that much.  In this election, it's a big difference, and this is an important question.

The new version of the calculator now "blends" exit poll and census data, along with other sources of information, to break down college vs. non-college white, and the differences are pretty stark.

The old version of the calculator had (with turnout levels unchanged from 2012):
33% Non-College White
37% College White
29% Non-White

The new version has:
42% Non-College White
31% College White
27% Non-White

These are huge changes; they're definitely more in line with what pollsters are assuming about the electorate.

My guess is the polls are weighting their samples to match the census data.  If the census data is wrong (because a lot of people lie about their past voting behavior), we could be in for a whopping Clinton victory on election day, as I argued earlier in this thread.

If the converse is true, and exit polls are oversampling college educated voters (or people with associate's degrees are responding Yes to "Are you a college graduate?"), we could be really excited early in the evening and then less so as the night goes on.

The changes do certainly make it easier to get within the calculator the sorts of results one would expect from the state polls (Trump picking up ME-2 and IA despite losing NC, for example).

[Mr. Morden]

How does the census dataset work?  The census bureau asks people some demographic questions, and also includes the question "Did you vote in the last presidential election?", then releases the demographic breakdown of people who answered "yes" to that question?

[Erc]

How does the census dataset work?  The census bureau asks people some demographic questions, and also includes the question "Did you vote in the last presidential election?", then releases the demographic breakdown of people who answered "yes" to that question?

It seems like, as a supplement to the November 2012 Current Population Survey, they ask people whether they are registered and whether they voted in the general election.

And yeah, they release all the appropriate crosstabs.

The numbers, of course, don't match up perfectly with exit polls or with the actual turnout results as reported by the state election divisions.  This mismatch with actual turnout is pretty bad in midterm years, but isn't so bad for Presidential years.

In 2012:
Actual Turnout: 129.2 m
CPS Turnout: 132.9 m

In 2008:
Actual Turnout: 131.4 m
CPS Turnout: 131.1 m

This suggests that (barring weird cancelling differences among different demographics) there isn't a huge prevalence of people lying about whether they voted in Presidential years.

So it comes down to whether you expect larger systematic issues with sampling in exit polls or in the CPS.  Honestly, since lying about voting doesn't seem to be a large effect on net, I'd be more inclined to trust the CPS rather than the exit polls.  It's very easy to see how exit polls might oversample college-educated voters (for a variety of reasons); less so with the CPS.

The education question for the exit poll asks whether you have:
1) No high school diploma
2) High school graduate
3) Some college / assoc. degree
4) College graduate
5) Postgraduate study

Since associate degrees are explicitly mentioned, it's unlikely that the reason for the discrepancy is people with associate degrees claiming they are college graduates.

[Mr. Morden]

In 2012:
Actual Turnout: 129.2 m
CPS Turnout: 132.9 m

That's only a 3% difference, which is actually much less of a mismatch than I would have guessed.  It seems odd to me that a 3% discrepancy in turnout #s would translate into a 10% discrepancy in the fraction of voters with a college degree.  The best explanation I can think of is that people are more likely to lie to exit pollsters about their educational status than they are to lie to the Census Bureau.

What alternative explanation is there?  Did either the Census Bureau or the exit pollsters do a poor job of selecting a representative sample of voters?

[Erc]

In 2012:
Actual Turnout: 129.2 m
CPS Turnout: 132.9 m

That's only a 3% difference, which is actually much less of a mismatch than I would have guessed.  It seems odd to me that a 3% discrepancy in turnout #s would translate into a 10% discrepancy in the fraction of voters with a college degree.  The best explanation I can think of is that people are more likely to lie to exit pollsters about their educational status than they are to lie to the Census Bureau.

What alternative explanation is there?  Did either the Census Bureau or the exit pollsters do a poor job of selecting a representative sample of voters?

My personal guess is that exit polls are just oversampling college educated voters.  College educated voters are more enthusiastic about voting / civics in the first place (as evidenced by their higher turnout, by any measure), and perhaps are more interested in spending time with an exit pollster.

There are of course also the usual geographic sampling concerns with exit polls, but it's hard to say a priori what sort of effect that would have.

[Mr. Morden]

In 2012:
Actual Turnout: 129.2 m
CPS Turnout: 132.9 m

That's only a 3% difference, which is actually much less of a mismatch than I would have guessed.  It seems odd to me that a 3% discrepancy in turnout #s would translate into a 10% discrepancy in the fraction of voters with a college degree.  The best explanation I can think of is that people are more likely to lie to exit pollsters about their educational status than they are to lie to the Census Bureau.

What alternative explanation is there?  Did either the Census Bureau or the exit pollsters do a poor job of selecting a representative sample of voters?

My personal guess is that exit polls are just oversampling college educated voters.  College educated voters are more enthusiastic about voting / civics in the first place (as evidenced by their higher turnout, by any measure), and perhaps are more interested in spending time with an exit pollster.

There are of course also the usual geographic sampling concerns with exit polls, but it's hard to say a priori what sort of effect that would have.

OK, here's my stupid question: What kind of demographic weighting, if any, do the exit pollsters do?  Do they just pick precincts that are demographically representative, and then poll every third person there, and let the chips fall where they may?  Or do they do anything to account for the possibility of different response rates from different demographic groups....other than weighting the eventual "topline" numbers (what % voted for Obama vs. what % voted for Romney) to match the election result?

[Mr. Morden]

And then there's the question...even if the exit poll #s are biased in a way that the Census #s are not, does that really mean that we should be weighting the current round of telephone polls to match the Census #s?  The telephone polls could have the same bias that the exit polls have.

[Erc]

And then there's the question...even if the exit poll #s are biased in a way that the Census #s are not, does that really mean that we should be weighting the current round of telephone polls to match the Census #s?  The telephone polls could have the same bias that the exit polls have.

If it's a response bias that's an issue in the exit polls, then we should certainly be weighting them to match the census; that's why pollsters do demographic weights.

If the bias is due to people lying about their education, then they shouldn't.

I definitely think it's more of the former than the latter, and thus the pollsters may very well be doing it right.  Of course, how this actually interacts with their likely voter screens is another question; these levels are not fixed in stone.

[Torie]

It'e remarkable that the polls are as accurate as they are.  The guessing about how to reweigh to deal with the fact that a majority of the calls get no response, to match the demographics of who you think will actually vote, seems more like a shot in the dark to me than science. I would not be surprised if the polls fall apart to a considerable extent, where there is sea change in the coalitions of the two parties. In this election cycle, we are seeing some of that, not a sea change perhaps, but certainly more than a zephyr. And the pollster do follow each other at the end, to avoid being left as an outlier, so if the polls fail, it will be most of them all together.

[Mr. Morden]

And then there's the question...even if the exit poll #s are biased in a way that the Census #s are not, does that really mean that we should be weighting the current round of telephone polls to match the Census #s?  The telephone polls could have the same bias that the exit polls have.

If it's a response bias that's an issue in the exit polls, then we should certainly be weighting them to match the census; that's why pollsters do demographic weights.

If the bias is due to people lying about their education, then they shouldn't.

Good point.  If you're right that it's a response bias in the exit polls, then I think that also means that the exit polls from past elections have also gotten it wrong wrt what % of the electorate with a college degree was voting Democratic vs. what % were voting Republican....since they are weighting the toplines to match the election outcome.

I guess one thing to do if someone has a lot of free time on their hands is to go back to pre-election polls from 2012, and look at what they were estimating *before* the election both for the fraction of the electorate with a college degree, and the fraction of each educational group supporting Obama or Romney.  Do those #s line up more with the exit polls or the census #s?

[Erc]

And then there's the question...even if the exit poll #s are biased in a way that the Census #s are not, does that really mean that we should be weighting the current round of telephone polls to match the Census #s?  The telephone polls could have the same bias that the exit polls have.

If it's a response bias that's an issue in the exit polls, then we should certainly be weighting them to match the census; that's why pollsters do demographic weights.

If the bias is due to people lying about their education, then they shouldn't.

Good point.  If you're right that it's a response bias in the exit polls, then I think that also means that the exit polls from past elections have also gotten it wrong wrt what % of the electorate with a college degree was voting Democratic vs. what % were voting Republican....since they are weighting the toplines to match the election outcome.

I guess one thing to do if someone has a lot of free time on their hands is to go back to pre-election polls from 2012, and look at what they were estimating *before* the election both for the fraction of the electorate with a college degree, and the fraction of each educational group supporting Obama or Romney.  Do those #s line up more with the exit polls or the census #s?

Here's an example from the last YouGov poll before the 2012 election (sadly, they don't have education crosstabs this cycle).

Topline: Obama 49 - Romney 47.

College Graduates (34%): Obama 53 - Romney 43
Non-College Graduates (66%): Obama 48 - Romney 47

Compare this to the exit polls:

Topline (adjusted to match the result): Obama 51 - Romney 47

College Graduates (47%): Obama 50 - Romney 48
Non-College Graduates (53%): Obama 51 - Romney 47

Note that the shares are quite different, and that the polarization is essentially nonexistent in the exit polling (and is in fact slightly in the opposite direction).

YouGov is a lot closer to the census data; this is not a surprise, as they heavily, heavily used the 2010 CPS to weight their responses (at least when it comes to registered voters; likely voters is a different question).

[Wisconsin+17]

Swing-o-matic is now much more resistant to swinging. MT isn't going to Clinton. I have to push the college educated vote to 57 percent Clinton to get close, but even that isn't enough. LA and MT will not go to Clinton this election.

[Wisconsin+17]

Interestingly, Trump doing a little better among all the other ethnic groups, a 64 percent share of whites without a degree will give a 337 Trump EC victory.

They also simulate the FREIWALL quite well.

Hillary wins with Trump getting 57 percent of the Whites without a degree, by holding the firewall without VA, but with CO and NV.

He needs a 4 percent shift, to 61 to finally crack the FRIEWALL. That's a 4 percent shift to flip one state.

[Fmr President & Senator Polnut]

And then there's the question...even if the exit poll #s are biased in a way that the Census #s are not, does that really mean that we should be weighting the current round of telephone polls to match the Census #s?  The telephone polls could have the same bias that the exit polls have.

If it's a response bias that's an issue in the exit polls, then we should certainly be weighting them to match the census; that's why pollsters do demographic weights.

If the bias is due to people lying about their education, then they shouldn't.

Good point.  If you're right that it's a response bias in the exit polls, then I think that also means that the exit polls from past elections have also gotten it wrong wrt what % of the electorate with a college degree was voting Democratic vs. what % were voting Republican....since they are weighting the toplines to match the election outcome.

I guess one thing to do if someone has a lot of free time on their hands is to go back to pre-election polls from 2012, and look at what they were estimating *before* the election both for the fraction of the electorate with a college degree, and the fraction of each educational group supporting Obama or Romney.  Do those #s line up more with the exit polls or the census #s?

Here's an example from the last YouGov poll before the 2012 election (sadly, they don't have education crosstabs this cycle).

Topline: Obama 49 - Romney 47.

College Graduates (34%): Obama 53 - Romney 43
Non-College Graduates (66%): Obama 48 - Romney 47

Compare this to the exit polls:

Topline (adjusted to match the result): Obama 51 - Romney 47

College Graduates (47%): Obama 50 - Romney 48
Non-College Graduates (53%): Obama 51 - Romney 47

Note that the shares are quite different, and that the polarization is essentially nonexistent in the exit polling (and is in fact slightly in the opposite direction).

YouGov is a lot closer to the census data; this is not a surprise, as they heavily, heavily used the 2010 CPS to weight their responses (at least when it comes to registered voters; likely voters is a different question).

I'm getting lost in this.

Are you saying the 538 decision was a good/bad or 'meh' decision?

[Mr. Morden]

*bump*

So supposedly the demographic crosstabs were supposed to be telling us that the topline #s in the polls were too Trump-friendly, when in fact it was the opposite.

So what happened?  Which demographics did the pre-election polls get right and wrong?

[muon2]

As a baseline measure of the effect of demographics I'll use this post from June. Note how it gets WI and PA right and has MI and NH on the edge.

I posted this as a prediction, in part because I was surprised at the effect of the 538 calculator on some variables.

I assume about a 6% drop in overall turnout driven by the unpopularity of the major candidates and anticipated negative campaign. That gives a turnout equal to 1996.

College whites 70%-54%R (from 77%-56%R); negative campaigns and disaffected college drop the turnout by 7% as it shifts 2% Dem.

Noncollege whites 53%-70%R (from 57%-62%); the Trump factor plays big here, and the turnout only drops 4% compared to the 6% average.

Blacks 56%-86%D (from 66%-93%D); the lack of Obama on the ticket returns black turnout to previous levels, slightly better than noncollege whites, and though still solid they drop to less than 90% Dem.

Latinos 44%-74%D (from 48%-71%); a drop in turnout equal to noncollege whites and 3% shift to the Dems.

Asians/Other 45%-70%D (from 49%-67%D);  a shift matching that of the Latinos.

Predicted vote Clinton 48.5%, Trump 49.8%. EV Clinton 232 Trump 306.

[Erich Maria Remarque]

Of course it was non-educated whites.

I remember how CNN polls was criticized several times for being too Trump-friendly by having non-coll-educated as high as 44-50% of all LV. But they might've got this trend. Too bad, they didn't have a "final" national poll.

As we know they are 46% of RV. So polls either underestimated their share, Trump's margin or mix of both.

Seems that polls were pretty good on Hispanics&Blacks. Latino Decisions were extremely awful, if exit polls to be believed.

[Mr. Morden]

I'd really like to see someone compare the exit poll demographic breakdown of 1) who showed up and 2) how each group's support split against what the polls were saying....and against the predictions in this thread of what was "realistic".

But I don't have time to do that myself.

[jaichind]

In theory the White share of the electorate fell from 72% to 70% from 2012 to 2016. But I am not sure about that.  Looking at 2012 vs 2016 exit polls we have

2012
White  72
AA       13
Latino  10
Asian     3
Other    2

2016
White  70
AA       12
Latino  11
Asian     4
Other    3

I am bit skeptical about the surge Other from 2->3.  A lot of it might be people that were labeled/identified as White in 2012 but being labeled/identified as bi-racial.  It seems that if we take that into account, despite the demographic decline of Whites from 2012 to 2016 their share of the electorate mostly stayed the same.  Trump have the added advantage of AA turnout being down which to be fair is coupled with a Latino turnout increase.  But Trump/Romney does better with Latinos versus AA so that shift is also a net win for Trump.