Rebuttal to Jacobson's "New Evidence for Old Arguments"

In "Salvation for the Spendthrift Incumbent" (Green and Krasno 1988), we argue that incumbent spending has a sizable effect on the House vote. This stands in direct contrast to Professor Jacobson's well-known view that "campaign spending by incumbents is not related to how well they do at the polls" (Jacobson 1983, 42, emphasis in the original). In his rebuttal Jacobson criticizes our findings on three grounds. First, he argues that the instrument we use in our twostage least squares model for incumbent spending is invalid. Second, he complains that our model fails to account for diminishing marginal returns. Finally, Jacobson asserts that our findings for the 1978 election do not hold for subsequent years. In this paper we briefly respond to these criticisms. Using data drawn from the 1976-86 elections, we demonstrate that incumbent spending has a substantial influence on the vote. We then critique the assumptions underlying Jacobson's individual-level analysis. In the end we find little empirical support for Jacobson's contention that the effects of incumbent spending are "substantively small and statistically insignificant." Much of Jacobson's essay focuses on the question of whether incumbent spending is as effective as challenger spending. This comparative question, however, occupies a minor place in our "Salvation" essay; our main objective was to show that incumbent spending has more than a trivial influence on electoral outcomes. We do not disagree, in fact, with Jacobson's position that the marginal effect of challenger spending exceeds that of incumbent spending. But this is not the only way to gauge the relative importance of incumbent and challenger spending. Another way would be to compare the yield, the number of votes "purchased" by challengers and incumbents in each district. This standard takes into account the fact that incumbents typically outspend their opponents. Data from 1976-86 indicate that the yield from incumbent spending is both considerable and on par with the yield from challenger expenditures. In sum, access to financial resources represents one of the important advantages of incumbency, for the spendthrift incumbent is able to offset the effects of campaign expenditures by the opposition.