Incumbent-Challenger and Incumbent-Runner-Up Advantage: Estimation and Bounds

• In Event: Poster Session: Political Methodology & Political Science Education & Civic Engagement
  In Poster Session: Poster Session: Political Methodology

Abstract

Different variants of the incumbency advantage concept have been applied in different settings, making cross-country comparisons difficult. We discuss these different variants and one that should be used in cross-country analysis. The incumbent-runner-up advantage can be estimated straightforwardly with Regression Discontinuity Design (RDD),but does not represent the most common variant in theoretical work, i.e., the incumbent-challenger advantage. The latter can be approximated with RDD comparing winners and runners-up under certain conditions. In a two-party system a party level estimate works. If the two-party condition fails, further assumptions are necessary, particularly on the imputed success of runners-up who are compliers (rerun only if won). Also, upper and lower bounds must be specified. We show that the upper-bound of the estimate of the incumbent-challenger advantage is equivalent to the upper-bound of the incumbent-runner-up advantage. Thus, the `upper-bound  incumbency advantage' can be estimated in most settings and has a clear meaning across concepts. We show results comparing this object across a series of countries. 

Authors

• Leandro M. De Magalhaes, University of Bristol

• Salomo Hirvonen, University of Bristol