Electoral Selection, Strategic Challenger Entry, and the Incumbency Advantage

We study the comparative statics of the incumbency advantage in a model of electoral selection and strategic challenger entry. The incumbency advantage arises in the model because, on average, incumbents have greater ability than challengers. This is true for two reasons: high-ability candidates are more likely to win election (electoral selection) and high-quality incumbents deter challengers (strategic challenger entry). We show that this quality-based incumbency advantage is expected to be greater for high visibility offices, in polities with relatively small partisan tides, in unpolarized electoral environments, and in electorates that are relatively balanced in their partisan preferences.