How surprising was Trump’s victory? Evaluations of the 2016 U.S. presidential election and a new poll aggregation model

The U.S. presidential election results of 2016 surprised many poll-watchers, suggesting possible biases in estimated support for the major party candidates and posing a challenge for poll aggregation as a prediction tool. Using data from earlier elections and the 2016 campaign, we evaluated poll aggregation performance for the major prediction web sites. We found that a proportional bias, partly due to non-major party preference during polling, had a large impact on state-level estimates. CONT.

Fred A. Wright (NC State) & Alec A. Wright (UNC), Electoral Studies