The Increasing Advantage of Incumbency in the U. S. States

This paper uses district-level electoral returns to estimate the size of the incumbency advantage in 24 U.S. states over the period from 1970 to 1986. Our major findings are two: first, the incumbency advantage in the median state roughly doubled over the time period investigated; second, this increase can be explained in terms of the growth of legislative operating budgets and, by inference, in casework and other particularistic services provided by state legislators to their constituents.