What Election Forecasts Mean for Electoral Competition and Voter Turnout

• In Event: Polling Results and Voters' Perceptions

Abstract

Recent years have seen a dramatic change in horserace coverage of elections in the U.S.---shifting focus from late-breaking poll numbers to sophisticated meta-analytic forecasts that emphasize candidates' chance of victory. Could this shift have an endogenous effect on election outcomes? We use data from Google News and Twitter to show just how much the media has shifted its focus to election forecasting, and use experiments to show that forecasting (1) increases certainty about an election's outcome and (2) decreases turnout in the context of an election simulation. Furthermore, we show that forecasting is more prominent in media outlets with liberal audiences and tends to affect the candidate who is ahead---raising questions about whether they contributed to Trump's victory over Clinton in 2016. We bring empirical evidence to this question, using ANES data to show that Democrats and Independents expressed an unusual confidence in a decisive 2016 election outcome---and that the same measure of confidence is associated with lower reported turnout.

Authors

• Solomon Messing, Facebook

• Yphtach Lelkes, University of Pennsylvania

• Sean Westwood, Dartmouth College