A regression discontinuity design analysis of the incumbency advantage and tenure in the U.S. House

This paper uses a regression discontinuity design to compare the incumbency advantage enjoyed by freshmen and non-freshmen incumbents. The results show that compared to freshmen incumbents that barely won the last election, non-freshmen incumbents that barely won get 2.3 percentage points more in the next election. Further results suggest that the ability to deter high quality challengers is an important source of that advantage.