(Not) Addressing Issues in Electoral Campaigns

Two candidates competing for election may raise some issues for debate during the electoral campaign, while avoiding others. We present a model in which the decision to introduce an issue, or to reply to the opponent's position on one that she raised, may result in further additions to the list of topics that end up being discussed. Candidates' strategic decisions are driven by their appraisal of their expected vote share at the end of the campaign. Our analysis appeals to a protocol-free equilibrium concept, and predicts the list of topics that will be touched upon by each candidate, and the order in which they might be addressed. We show that important phenomena observed during campaigns, like the convergence of the parties to address the same issues, or else their diverging choice on which ones to treat, or the relevance of issue ownership can be explained within our stark basic model.