The binary policy model

We introduce a tractable multi-issue model of electoral competition in which candidates are ex-ogenously committed to particular positions on a subset of issues, while they can choose a sequence of binary positions for the remaining issues to maximize their winning probability. A majority-efficient position is defined as one where a candidate cannot make a majority of the electorate better off, taking as given his fixed positions. We characterize conditions for majority-efficient positions to exist. In contrast to models where candidates can choose all relevant positions, the candidates’ fixed positions in our framework imply that only some voters are swing voters. Whether candidates choose majority-efficient or majority-inefficient positions depends on properties of the distribution of these swing voters. We also use our framework to analyze plurality rule and runoff rule in elec-tions with multiple candidates