HorsesAss.Org

  • Home
  • About HA
  • Advertise
  • Archives
  • Donate

2016 National Polling

by Darryl — Thursday, 11/10/16, 3:18 pm

How did the pollsters do for the 2016 election? That is a big and complicated question, because there are many different types and levels of polling done. In this post, I’ll look at the national polling in the Clinton—Trump race.

If my Twitter feed is any indication, the media seems hell-bent on the meme that “the polling was terrible” or “this is the end of polling.” But, as I show below, it wasn’t completely terrible for the national polling.

Yesterday, I heard a story on KUOW (I don’t remember the show, but perhaps All Things Considered or Here & Now) about the national polls. The story had things exactly wrong. They interviewed the director of the LA Times/USC poll (you know, the one that consistently had Trump leading Clinton), introducing it as “the one that got it right.” In fact, the LA Times/USC poll was the one that got it wrong.

Remember, national polls only tell us about the popular vote. And, as of this morning, Clinton leads in the popular vote. The LA Times/USC poll does use very interesting methods, asking their internet panel of respondents the probability of voting for each candidate. That is very cool (except for the internet panel part). But ultimately something about their poll led them to, almost uniquely, pick the wrong winner.

There are other criteria besides picking the right/wrong winner that are useful for evaluating the polls. A natural criterion is to ask which poll gets the percentages closest. That is what I have done. I’ve taken the national polling data as posted by Real Clear Politics and statistically evaluated “goodness of fit” between the poll result and the actual election outcome (as of this morning). The test I use is call a G-test of Goodness of Fit.

First I begin with the polls that did 2-way Clinton–Trump match-ups. Here are the polls from 31 Oct on, sorted newest to oldest (click for a larger image):

table1

The “fit” of the poll is better for smaller numbers in the X^2 column, and the last column gives, essentially, the probability of observing deviations from the actual outcome at least this large given the sample size, assuming the poll was a true reflection of the outcome. I’ve highlighted the best fitting with darker colors (orange). The shades of yellow denote other polls that do not differ significantly. The worst fitting, those that differ significantly from the results, are shown in white.

The best polls are the four highlighted in orange, in order: The Gravis poll taken on 31 October, the FOX News poll taken from 1-3 Nov, IBD/TIPP Tracking poll taken 4-7 Nov, and the McClatchy poll taken 1-3 Nov. Odd that the three oldest polls are the closest.

The worst poll, by far, was the NBC News/Survey Monkey online tracking poll. This poll was way too optimistic for Clinton.

The LA Times/USC poll was middling. There is only a 6% probability of observing results this bad by chance. And, of course, the poll got the wrong winner.

But we see, using 4-way races, most of the national polls were, statistically, in the ball park. Ten of 14 weren’t had outcomes that were not statistically different from the actual election.

Here is the polling for the 4-way race. The extra two categories (Johnson and Stein) provides for more ways a poll can “deviate” from the observed election results, so the polls don’t fit as well overall. Many polls are heavily penalized for doing a lousy job in the Johnson or Stein percentages, even if the Trump and Clinton percentages are okay.

table2

The best poll was by Gravis on 1-2 Nov. A later Gravis poll taken 3-6 Nov was actually one of the worst polls.

We see that, looking at a four-way race, the pollsters did not do that well. Only two of 19 polls did the results not differ significantly from the actual four-candidate distribution.

But what if we only consider the races that matter—Clinton and Trump? I’ve taken the four-way races and turned them into 2-way races. Mathematically, when doing the test, I “normalize” the results so that the sum of Clinton and Trump percentages are now 100%.

table3

We see that for 14 of the 19 polls, the results did not differ from the actual outcome. Again, the worst poll, by far, was the NBC News/Survey Monkey online tracking poll. With such a large sample, they should have been much closer than they ended up being.

So, whatever you’ve heard, the national polls were generally not that far off in predicting two outcomes of the popular vote: The winner of Clinton v. Trump, and the relative proportions of Clinton v. Trump votes.

Share:

  • Facebook
  • Reddit
  • LinkedIn
  • Email
  • Print

Related

Comments

  1. 1

    ArtFart spews:

    Thursday, 11/10/16 at 4:00 pm

    In this case, it might be appropriate to refer to NPR’s program by the label applied to it by Rush Limbaugh years ago: “All Things Distorted”.

  2. 2

    Mark Adams spews:

    Friday, 11/11/16 at 6:37 pm

    Of course it’s a misuse of polls to rely on them as to predict the outcome of a political race. Otherwise gamblers would use them at the horse races. Which are always more fun when someone other than the best horse and/or the best jockey who are the favorites win. I think some pollsters are in trouble as the results fell outside of the vig.

Recent HA Brilliance…

  • Monday Open Thread Monday, 6/16/25
  • Friday Night Multimedia Extravaganza! Friday, 6/13/25
  • Friday Open Thread Friday, 6/13/25
  • Wednesday Open Thread Wednesday, 6/11/25
  • Drinking Liberally — Seattle Tuesday, 6/10/25
  • Monday Open Thread Monday, 6/9/25
  • Friday Night Multimedia Extravaganza! Friday, 6/6/25
  • Monday Open Thread Friday, 6/6/25
  • Wednesday! Wednesday, 6/4/25
  • Drinking Liberally — Seattle Tuesday, 6/3/25

Tweets from @GoldyHA

I no longer use Twitter because, you know, Elon is a fascist. But I do post occasionally to BlueSky @goldyha.bsky.social

From the Cesspool…

  • Vicious Troll on Monday Open Thread
  • RedReformed on Monday Open Thread
  • G on Monday Open Thread
  • G on Monday Open Thread
  • EvergreenRailfan on Monday Open Thread
  • Roger Rabbit on Monday Open Thread
  • EvergreenRailfan on Monday Open Thread
  • lmao on Monday Open Thread
  • lmao on Monday Open Thread
  • lmao on Monday Open Thread

Please Donate

Currency:

Amount:

Archives

Can’t Bring Yourself to Type the Word “Ass”?

Eager to share our brilliant political commentary and blunt media criticism, but too genteel to link to horsesass.org? Well, good news, ladies: we also answer to HASeattle.com, because, you know, whatever. You're welcome!

Search HA

Follow Goldy

[iire_social_icons]

HA Commenting Policy

It may be hard to believe from the vile nature of the threads, but yes, we have a commenting policy. Comments containing libel, copyright violations, spam, blatant sock puppetry, and deliberate off-topic trolling are all strictly prohibited, and may be deleted on an entirely arbitrary, sporadic, and selective basis. And repeat offenders may be banned! This is my blog. Life isn’t fair.

© 2004–2025, All rights reserved worldwide. Except for the comment threads. Because fuck those guys. So there.