What Persuades Voters? A Field Experiment on Political Campaigning

Political campaigns spend millions of dollars each voting cycle on persuading voters, and it is well established that these campaigns do affect voting decisions. What is less understood is what element of campaigning—the content of the message or the delivery method itself— sways voters, a question that relates back to how advertising works generally. We use a field experiment in a 2010 general election for local office to identify the persuasive mechanism behind a particular form of campaigning: candidate door-to-door canvassing. In the experiment, the candidate either canvassed a household or left literature without meeting the voters. In addition, the literature either contained information on the candidate or on how to vote. Our main result is that voters are most persuaded by personal contact (the delivery method), rather than the content of the message. Given our setting, we conclude that personal contact seems to work, not through social pressure, but by providing a costly or verifiable signal of quality.