The Long-Term and Geographically Constrained Effects of Campaign Advertising on Political Polarization and Sorting

Abstract

Scholars agree that there has been an increase in polarization among political elites, though there continues to be debate on the extent to which polarization exists among the mass public. Still, there is general agreement that the American public has become more sorted over the past two decades, a time during which political ad volumes have increased and ads have become more negative. In this research, we explore whether there is a link between the two. We take advantage of variation in the volume and tone of political advertising across media markets to examine the link between advertising and three dependent variables: issue polarization, affective polarization, and sorting. We focus on the impact of both recent ad exposure and cumulative ad exposure across several election cycles. Ultimately, we find little impact of advertising on polarization or sorting, both overall and among subgroups of the population.