Political Persuasion

Abstract

How can competing political parties use persuasion to win elections? To study the role of competition in persuasion, I construct a voting model where two political parties compete by designing campaigns that release information about their party's candidate. By designing the whole campaign—as compared to designing a particular message—political parties are able to systematically change the beliefs of a Bayesian voter. Campaigns generate distributions of voter beliefs about the candidate's quality. Under competition, each party must worry about the other party and does not want to design a campaign that is easy to beat. In the unique equilibrium, both parties design campaigns that generate uniform distributions. The uniform distribution means that the voter is equally likely to have a range of beliefs about the candidate's quality after the campaign. It also means that the voter has maximum uncertainty about the candidates.