Microtargeting, Divisive Campaigns and the Rise in Voter Polarization

This paper studies the effects of interactions between campaign spending and ideology on voter polarization. In a setting where microtargeting of advertisements is prevalent, we consider how differences in the resources available to the parties competing in an election, affect the campaign and voter polarization.Spending allocation across the electorate is studied. We show that the joint distribution of party expenditures over the electorate is single peaked, and reaches a maximum for a specific value of the ideological bias of the voters. This value corresponds to the focus of the campaign, and shifts from swing voters to the strongest partisans of the party with the smallest budget, as the budget gap increases. After this shift, the campaign is more divisive because party messages increasingly deal with wedge issues. A rise in voter polarization follows, which increases as electoral competition becomes more unequal in terms of party campaign expenditures