New Paper Questions Accuracy of Voter Predictions

January 9, 2012
By Doug Gavel

Public opinion polling data is of critical importance to political candidates and campaign strategists, but a new Harvard Kennedy School Faculty Working Paper raises serious questions about the accuracy of certain datasets, specifically those relating to predicted voter turnout. "Why Bother Asking? The Limited Value of Self-Reported Vote Intention" is co-authored by Todd Rogers, assistant professor of public policy.

In the paper, Rogers and co-author Masa Aida of Greenberg Quinlan Rosner Research analyzed phone surveys from three recent elections to compare pre-election predictions with actual voting outcomes. The results are intriguing.

"Unsurprisingly, many who predict they will vote actually do not vote," Rogers and Aida write. "More surprisingly, many who predict they will not vote actually do vote (29% to 56%)."

In fact, Rogers and Aida find, "records of past voting behavior predicts turnout substantially better than self-prediction."

The authors argue that their findings should affect the thinking about voter registration policy. "Recall that a large proportion of eligible voters who predicted that they would not vote actually did vote. This suggests that scheduling the deadline for voter registration in advance of an election (as all but a small number of states currently do) may reduce overall turnout. Registration in advance of an election requires that citizens anticipate their interest for casting a vote in an election, and the results we report show that people's ability to do that is limited," they write.

The authors also argue that pollsters need to utilize a hybrid approach, incorporating both self-report and voter file data, to more accurately predict voter turnout on Election Day.

Todd Rogers is an assistant professor of public policy at the Harvard Kennedy School. He is a behavioral scientist who tries to understand and influence socially consequential problems. He was named a Rising Star by Politics Magazine for his work in the 2008 election cycle, and a 40 under 40 award winner by New Leaders Council for leadership in politics.

Todd Rogers headshot

Todd Rogers, assistant professor of public policy

"Unsurprisingly, many who predict they will vote actually do not vote," writes Rogers.

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