Working Paper: NBER ID: w10748
Authors: Gautam Gowrisankaran; Matthew F. Mitchell; Andrea Moro
Abstract: Since 1914, incumbent U.S. senators running for reelection have won almost 80% of the time. We investigate why incumbents win so often. We allow for three potential explanations for the incumbency advantage: selection, tenure, and challenger quality, which are separately identified using histories of election outcomes following an open seat election. We specify a dynamic model of voter behavior that allows for these three effects, and structurally estimate the parameters of the model using U.S. Senate data. We find that tenure effects are negative or small. We also find that incumbents face weaker challengers than candidates running for open seats. If incumbents faced challengers as strong as candidates for open seats, the incumbency advantage would be cut in half.
Keywords: No keywords provided
JEL Codes: H1; J2; C5
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| tenure effects (C41) | reelection probabilities (D79) |
| tenure effects (C41) | incumbency advantage (D72) |
| challenger quality (L15) | incumbency advantage (D72) |
| incumbents face weaker challengers (D72) | incumbency advantage (D72) |
| selection effects (C52) | incumbency advantage (D72) |