Decomposing the Sources of Incumbency Advantage in the U. S. House

Abstract

This paper develops a model of incumbency advantage that takes into account candidate quality, and then estimates the parameters of that model using panel data on the U.S. House from 1948 to 1990. Our approach allows us to go beyond the previous literature, which has focused primarily on measurement of incumbency advantage, to a decomposition of its sources. The primary explanation for the rising incumbency advantage appears to be the increasing ability of incumbents to deter high-quality challengers. In contrast, direct officeholder benefits (e.g., franking privileges, media exposure, fund-raising advantages, etc.) have been relatively stable over time and now account for less than half of the overall incumbency advantage.