4/19/17 - Douglas Rivers (Stanford) - What the Hell Happened? The Perils of Polling in the 2016 U.S. Election

Publication information:

4/19/17 - Douglas Rivers (Stanford) - What the Hell Happened? The Perils of Polling in the 2016 U.S. Election. 2017.

Abstract

Douglas Rivers (Stanford) presents

What the Hell Happened?
The Perils of Polling in the 2016 U.S. Election

Most polls at the end of the 2016 U.S. Presidential election campaign showed Hillary Clinton leading Donald Trump and she did indeed win the popular vote by a margin of over two percent. However, several anomalies are apparent in 2016 polling:

1) Some polling exhibited "phantom swings" in support for Clinton and Trump.
2) There is clear evidence of bias in midwestern state polls.
3) Underestimates of mean squared polling error caused poll aggregators to over-estimate Clinton's chances of winning.
4) Republican turnout in 2016 was underestimated by both likely voter screens and historical turnout models.

With the benefit of hindsight, most of these problems could have been avoided. Improved methods are discussed, along with speculations about the limits of campaign analytics.


Full text

Douglas Rivers (Stanford) presents

What the Hell Happened?
The Perils of Polling in the 2016 U.S. Election

Most polls at the end of the 2016 U.S. Presidential election campaign showed Hillary Clinton leading Donald Trump and she did indeed win the popular vote by a margin of over two percent. However, several anomalies are apparent in 2016 polling:

1) Some polling exhibited "phantom swings" in support for Clinton and Trump.
2) There is clear evidence of bias in midwestern state polls.
3) Underestimates of mean squared polling error caused poll aggregators to over-estimate Clinton's chances of winning.
4) Republican turnout in 2016 was underestimated by both likely voter screens and historical turnout models.

With the benefit of hindsight, most of these problems could have been avoided. Improved methods are discussed, along with speculations about the limits of campaign analytics.