All the Best Polls Agree with Me: Bias in Evaluations of Political Polling

Abstract

Do Americans consider polling results an objective source of information? Experts tend to evaluate the credibility of polls based on the survey methods used, vendor track record, and data transparency, but it is unclear if the public does the same. In two different experimental studies—one focusing on candidate evaluations in the 2016 U.S. election and one on a policy issue—we find a significant factor in respondent assessments of polling credibility to be the poll results themselves. Respondents viewed polls as more credible when majority opinion matched their opinion. Moreover, we find evidence of attitude polarization after viewing polling results, suggesting motivated reasoning in the evaluations of political polls. These findings indicate that evaluations of polls are biased by motivated reasoning and suggest that such biases could constrain the possible impact of polls on political decision making.