Does Spending More Than the Challenger Lead to a Greater Percentage of the Vote?

Previous studies indicate that campaign spending is not a significant factor in determining an incumbent’s share of the vote. In this study, only “competitive” races, defined by Cook Political Report as “Lean Republican,” “Even” or “Lean Democratic”, were considered to examine the the significance of campaign spending without endogenous effects. Other variables, such as the district’s median income, district’s population, number of terms in office, type of race (Senate or House), and education level were also analyzed for their effects on campaign spending and vote share. Results of the present study suggest that the higher the spending difference between the incumbent and the challenger, the greater the incumbent’s vote share. The effect of campaign spending also decreases at higher levels of spending and increases with candidates that have longer political careers