An Evaluation of the 2016 Election Polls in the United States

Courtney Kennedy, Mark Blumenthal, Scott Clement, Joshua D. Clinton, Claire Durand, Charles Franklin, Kyley McGeeney, Lee Miringoff, Kristen M Olson, Douglas Rivers, Lydia Saad, G. Evans Witt, Christopher Wlezien

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The 2016 presidential election was a jarring event for polling in the United States. Preelection polls fueled high-profile predictions that Hillary Clinton's likelihood of winning the presidency was about 90 percent, with estimates ranging from 71 to over 99 percent. When Donald Trump was declared the winner of the presidency, there was a widespread perception that the polls failed. But did the polls fail? And if so, why? Those are among the central questions addressed by an American Association for Public Opinion Research (AAPOR) ad hoc committee. This paper presents the committee's analysis of the performance of preelection polls in 2016, how that performance compares to polling in prior elections, and the extent to which performance varied by poll design. In addition, the committee examined several theories as to why many polls, particularly in the Upper Midwest, underestimated support for Trump. The explanations for which the most evidence exists are a late swing in vote preference toward Trump and a pervasive failure to adjust for overrepresentation of college graduates (who favored Clinton). In addition, there is clear evidence that voter turnout changed from 2012 to 2016 in ways that favored Trump, though there is only mixed evidence that misspecified likely voter models were a major cause of the systematic polling error. Finally, there is little evidence that socially desirable (Shy Trump) responding was an important contributor to poll error.

Original languageEnglish (US)
Pages (from-to)1-33
Number of pages33
JournalPublic Opinion Quarterly
Volume82
Issue number1
DOIs
StatePublished - Mar 6 2018

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Systematic errors
election
evaluation
evidence
voter
performance
voter turnout
opinion research
presidential election
public opinion
graduate
cause
Elections
Polls
Evaluation
event
Polling

ASJC Scopus subject areas

  • Communication
  • History
  • Sociology and Political Science
  • Social Sciences(all)
  • History and Philosophy of Science

Cite this

Kennedy, C., Blumenthal, M., Clement, S., Clinton, J. D., Durand, C., Franklin, C., ... Wlezien, C. (2018). An Evaluation of the 2016 Election Polls in the United States. Public Opinion Quarterly, 82(1), 1-33. https://doi.org/10.1093/poq/nfx047

An Evaluation of the 2016 Election Polls in the United States. / Kennedy, Courtney; Blumenthal, Mark; Clement, Scott; Clinton, Joshua D.; Durand, Claire; Franklin, Charles; McGeeney, Kyley; Miringoff, Lee; Olson, Kristen M; Rivers, Douglas; Saad, Lydia; Witt, G. Evans; Wlezien, Christopher.

In: Public Opinion Quarterly, Vol. 82, No. 1, 06.03.2018, p. 1-33.

Research output: Contribution to journalArticle

Kennedy, C, Blumenthal, M, Clement, S, Clinton, JD, Durand, C, Franklin, C, McGeeney, K, Miringoff, L, Olson, KM, Rivers, D, Saad, L, Witt, GE & Wlezien, C 2018, 'An Evaluation of the 2016 Election Polls in the United States', Public Opinion Quarterly, vol. 82, no. 1, pp. 1-33. https://doi.org/10.1093/poq/nfx047
Kennedy C, Blumenthal M, Clement S, Clinton JD, Durand C, Franklin C et al. An Evaluation of the 2016 Election Polls in the United States. Public Opinion Quarterly. 2018 Mar 6;82(1):1-33. https://doi.org/10.1093/poq/nfx047
Kennedy, Courtney ; Blumenthal, Mark ; Clement, Scott ; Clinton, Joshua D. ; Durand, Claire ; Franklin, Charles ; McGeeney, Kyley ; Miringoff, Lee ; Olson, Kristen M ; Rivers, Douglas ; Saad, Lydia ; Witt, G. Evans ; Wlezien, Christopher. / An Evaluation of the 2016 Election Polls in the United States. In: Public Opinion Quarterly. 2018 ; Vol. 82, No. 1. pp. 1-33.
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