Why Do Incumbent Senators Win? Evidence from a Dynamic Selection Model

35 Pages Posted: 23 Sep 2004 Last revised: 14 Nov 2022

See all articles by Gautam Gowrisankaran

Gautam Gowrisankaran

Columbia University; HEC Montreal; Centre for Economic Policy Research (CEPR); National Bureau of Economic Research (NBER)

Matthew F. Mitchell

Rotman School of Management

Andrea Moro

Vanderbilt University - College of Arts and Science - Department of Economics

Date Written: September 2004

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.

Suggested Citation

Gowrisankaran, Gautam and Mitchell, Matthew F. and Moro, Andrea, Why Do Incumbent Senators Win? Evidence from a Dynamic Selection Model (September 2004). NBER Working Paper No. w10748, Available at SSRN: https://ssrn.com/abstract=590742

Gautam Gowrisankaran (Contact Author)

Columbia University ( email )

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National Bureau of Economic Research (NBER) ( email )

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Matthew F. Mitchell

Rotman School of Management ( email )

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Andrea Moro

Vanderbilt University - College of Arts and Science - Department of Economics ( email )

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