As the 2016 presidential primaries approach, voters in key states are being inundated with political ads every time they turn on the TV. But how much do these costly advertisements actually impact election results?
Decades of conventional social-science wisdom would say not much. The so-called “minimal-effects hypothesis,” formulated in the mid–20th century, asserts that political TV ads do not help get out the vote, with numerous studies showing that ads had little to no impact on aggregate voter turnout. More recent studies have cast doubts on the hypothesis. Still, “there’s no consensus,” says Jörg Spenkuch, who studies voting systems at the Kellogg School of Management.
Spenkuch found this lack of conclusive evidence troubling. “It seems implausible that political advertising only has minimal effects,” he says. “It would mean that campaigns are making billion-dollar mistakes every four years.”
Spenkuch, an assistant professor of managerial economics and decision sciences, and coauthor David Toniatti of the economic consulting firm Analysis Group, used a clever quasi-experimental approach based on data from the 2004 and 2008 presidential races to answer this question. Their findings: political advertisements do not change overall voter turnout, but they do impact which candidate gets the most votes by rallying that candidate’s base.