TY  - JOUR
AU  - Gowrisankaran,Gautam
AU  - Mitchell,Matthew F.
AU  - Moro,Andrea
TI  - Why Do Incumbent Senators Win? Evidence from a Dynamic Selection Model
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 10748
PY  - 2004
Y2  - September 2004
UR  - http://www.nber.org/papers/w10748
L1  - http://www.nber.org/papers/w10748.pdf
N1  - Author contact info:
Gautam Gowrisankaran
Professor of Economics
Department of Economics
University of Arizona
P.O. Box 210108
Tucson, AZ 85721-0108
Tel: 520/621-2529
Fax: 520/621-8450
E-Mail: gowrisankaran@eller.arizona.edu

Andrea Moro
Department of Economics
Vanderbilt University
VU Station B #351819
Nashville, TN 37235
E-Mail: andrea.moro@vanderbilt.edu
AB  - 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.
ER  -