High rerunning rates among incumbents and among the two major parties allow studies of U.S. incumbency advantage to bypass the selection problem of who chooses to rerun. In countries where rerunning is not widespread among individuals or parties, estimation using methods developed for the United States may result in a sample selection bias. In countries with party switching, there may be a disconnect between party and individual estimates. This article proposes a definition of incumbency advantage that is valid for countries that present any of these characteristics and that is valid for cross-country comparison: the effect of incumbency for an individual politician on the unconditional probability of winning. I illustrate the issues raised in this article with evidence from Brazilian mayoral elections.
- Incumbency Advantage
- Mayoral elections
- Regression Discontinuity Design