The Threat of the Dollar: The Impact of Earmarks on Running Uncontested in U.S. House Races.

House members looking to preserve their seat are at a notable advantage in comparison to potential challengers (Erikson 1971; Bickers and Stein 1996). While many factors influence incumbent advantage, few studies have been devoted to an incumbents' ability to solidify the ultimate form of incumbent security: running unopposed (for exceptions see Wrighton and Squire 1997; Squire 1989). This paper explores the tool of earmarks, a means for all incumbents to fortify their electoral advantage and deter challengers. Utilizing newly-released data on Congressional earmarks from fiscal year 2009, this paper focuses on the 2010 election to draw three substantive conclusions. First, earmarks have no measurable effect on running uncontested for Representatives from safe districts (that is districts where the incumbent received sixty percent or more of the vote in the last election). Second, as would be expected, being elected to a marginal district results in a reduced probability of running uncontested in the next election. Finally, when interacted, for those from marginal districts, earmarks have a significant and positive impact on increasing the chances a member will run unopposed. [ABSTRACT FROM AUTHOR]