Strategic Interaction and Candidate Competition in U.S. House Elections: Empirical Applications of Probit and Strategic Probit Models

In recent work, Signorino (American Political Science Review93:279–297, 1999; International Interactions 28:93–115,2002) has sought to test statistical models derived from extensive-formgames in the context of international relations research focusingon conflict and interstate bargaining. When two or more actorsinteract with one another under conditions of uncertainty, Signorinodemonstrates that it is necessary to incorporate such strategicinteraction into the underlying model to avoid potential threatsto statistical inference. Outside the realm of internationalrelations research, however, there have been limited applicationsof Signorino's strategic probit model in understanding strategicinteraction. In this article, I present an empirical comparisonof probit and strategic probit models in the context of candidatecompetition in House elections during the 1990s. I show thatincumbent spending deters challenger entry and factors suchas minority party affiliation and redistricting significantlyaffect incumbent career decisions, findings that run counterto those reported in the nonstrategic model. Overall, the resultsillustrate that failing to account for strategic interactioncan lead to biased and inaccurate estimates related to challengerand incumbent entry decisions.