The Financial Incumbency Advantage: Causes and Consequences

In this article, we use a regression discontinuity design to estimate the causal effect of incumbency on campaign contributions in the U.S. House and state legislatures. In both settings, incumbency causes approximately a 20–25 percentage-point increase in the share of donations flowing to the incumbent’s party. The effect size does not vary with legislator experience and does not appear to depend on incumbent office-holder benefits. Instead, as...