A Theory of Communication in Political Campaigns

In this paper I develop a formal theory of campaign communications. Voters have priors about the quality of candidates' policies in the different policy issues and about the issues’ relative importance. Candidates spend time or money (TV ads, public speeches, etc.) in an effort to influence voters' decisions at the ballot. Influence has two simultaneous effects: (i) it increases the quality of the policy in the issue as perceived by the voters through policy advertising and (ii) it makes the issue more salient through issue priming, thereby increasing the issue's perceived importance. A strategy is an allocation of influence activities to the different issues or topics. I show conditions under which candidates’ strategies converge or diverge, which issues – if any – will dominate the campaign, and under what conditions candidates are forced to focus on issues in which they are perceived to be weak. I develop a set of novel testable predictions and discuss the model’s predictive power by example of the 2008 presidential campaign in the U.S