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Did Shy Trump Supporters Bias the 2016 Polls? Evidence from a Nationally-representative List Experiment

Alexander CoppockORCID iD: http://orcid.org/0000-0002-5733-2386
Published Online: 2017-06-26 | DOI: https://doi.org/10.1515/spp-2016-0005


Explanations for the failure to predict Donald Trump’s win in the 2016 Presidential election sometimes include the “Shy Trump Supporter” hypothesis, according to which some Trump supporters succumb to social desirability bias and hide their vote preference from pollsters. I evaluate this hypothesis by comparing direct question and list experimental estimates of Trump support in a nationally representative survey of 5290 American adults fielded from September 2 to September 13, 2016. Of these, 32.5% report supporting Trump’s candidacy. A list experiment conducted on the same respondents yields an estimate 29.6%, suggesting that Trump’s poll numbers were not artificially deflated by social desirability bias as the list experiment estimate is actually lower than direct question estimate. I further investigate differences across measurement modes for relevant demographic and political subgroups and find no evidence in support of the “Shy Trump Supporter” hypothesis.


  • Aronow, P. M., A. Coppock, F. W. Crawford and D. P. Green (2015) “Combining List Experiment and Direct Question Estimates of Sensitive Behavior Prevalence,” Journal of Survey Statistics and Methodology, 3:43–66.CrossrefGoogle Scholar

  • Blair, G. and K. Imai (2012) “Statistical Analysis of List Experiments,” Political Analysis, 20:47–77.CrossrefGoogle Scholar

  • Curtice, J. (1997) “So How Well Did They Do? The Polls in the 1997 Election,” Journal of the Market Research Society, 39:449–462.Google Scholar

  • Dropp, K. (2015) “Why Does Donald Trump Perform Better in Online Versus Live Telephone Polling?”.Google Scholar

  • Dropp, K. (2016) “Yes, There Are Shy Trump Voters. No, They Won’t Swing the Election,” URL https://morningconsult.com/2016/11/03/yes-shy-trump-voters-no-wont-swing-election/.

  • Durand, C., A. Blais and S. Vachon (2001) “Review: A Late Campaign Swing or a Failure of the Polls? The Case of the 1998 Quebec Election,” The Public Opinion Quarterly, 65:108–123.Google Scholar

  • Frye, T., S. Gehlbach, K. L. Marquardt and O. J. Reuter (2016) “Is Putin’s Popularity Real?” Post-Soviet Affairs, 1–15.Google Scholar

  • Glynn, A. N. (2013) “What Can We Learn with Statistical Truth Serum? Design and Analysis of the List Experiment,” Public Opinion Quarterly, 77:159–172.CrossrefGoogle Scholar

  • Hopkins, D. J. (2009) “No More Wilder Effect, Never a Whitman Effect: When and Why Polls Mislead about Black and Female Candidates,” The Journal of Politics, 71:769–781.CrossrefGoogle Scholar

  • Imai, K. (2011) “Multivariate Regression Analysis for the Item Count Technique,” Journal of the American Statistical Association, 106:407–416.CrossrefGoogle Scholar

  • Kuklinski, J. H., P. M. Sniderman, K. Knight, T. Piazza, P. E. Tetlock, G. R. Lawrence and B. Mellers (1997) “Racial Prejudice and Attitudes Toward Affirmative Action,” American Journal of Political Science, 41:402–419.CrossrefGoogle Scholar

  • LaBrie, J. W. and M. Earleywine (2000) “Sexual Risk Behaviors and Alcohol: Higher Base Rates Revealed Using the Unmatched-Count Technique,” Journal of Sex Research, 37:321–326.CrossrefGoogle Scholar

  • Lax, J. R., J. H. Phillips and A. F. Stollwerk (2016) “Are Survey Respondents Lying About Their Support for Same-Sex Marriage? Lessons from a List Experiment,” Public Opinion Quarterly, 80:510–533.CrossrefGoogle Scholar

  • Lyall, J., G. Blair and K. Imai (2013) “Explaining Support for Combatants duringWartime: A Survey Experiment in Afghanistan,” American Political Science Review, 107:679–705.CrossrefGoogle Scholar

  • Mellon, J. and C. Prosser (2017) “Missing Nonvoters and Misweighted Samples: Explaining the 2015 Great British Polling Miss,” Public Opinion Quarterly, forthcoming.Google Scholar

  • Miller, J. (1984) A New Survey Technique for Studying Deviant Behavior, Phd thesis., George Washington University.

  • Payne, J. G. (2010) “The Bradley Effect: Mediated Reality of Race and Politics in the 2008 US Presidential Election,” American Behavioral Scientist, 54: 417–435.CrossrefGoogle Scholar

  • Powell, R. J. (2013) “Social Desirability Bias in Polling on Same-sex Marriage Ballot Measures,” American Politics Research, 41:1052–1070.CrossrefGoogle Scholar

  • Streb, M. J., B. Burrell, B. Frederick and M. A. Genovese (2008) “Social Desirability Effects and Support for a Female American President,” Public Opinion Quarterly, 72:76–89.CrossrefGoogle Scholar

About the article

Published Online: 2017-06-26

Published in Print: 2017-10-26

Citation Information: Statistics, Politics and Policy, Volume 8, Issue 1, Pages 29–40, ISSN (Online) 2151-7509, ISSN (Print) 2194-6299, DOI: https://doi.org/10.1515/spp-2016-0005.

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