This paper studies the relationship between incumbents' performance and political polarization, both with theory and data. The theory is based on a spatial model of political competition in which the voters use the incumbent's performance in office to update their beliefs about his competence. A...

We combine Duverger's Law (1954) with Demsetz's (1968) theory of natural monopoly to provide a novel perspective on electoral competitiveness in a single member district, plurality rule system. In the framework we develop, competitiveness depends on the contestability of elections, which...

We show that a large electorate of ignorant voters can succeed in establishing high levels of electoral accountability. In our model an incumbent politician is confronted with a large number of voters who receive very noisy signals about her performance. We find that the accountability problem...