Research

Strategic Mobilization: Why Disproportional Districts Encourage Partisan Mobilization Efforts

Many scholars suggest that proportional representation increases party mobilization by creating nationally competitive districts that give parties an incentive to mobilize everywhere. This paper provides theoretical and empirical evidence that brings this claim into question. I propose, unlike earlier scholars, that the positive effect of district competitiveness on party mobilization efforts increases as electoral districts become more disproportional, arguing that disproportionality itself encourages mobilization and exaggerates the impact of competitiveness on mobilization. Game-theoretic predictions tested with individual-level survey data from national legislative elections show mobilization levels are much higher and that district competitiveness has a much larger positive effect on parties’ mobilization efforts in single-member districts. Overall, the theoretical and empirical evidence suggests that proportional electoral rules give parties no strong incentive to mobilize anywhere.

Testing Hypotheses of No Meaningful Effect

While most hypotheses in political science suggest positive or negative effects, a substantial subset of important hypotheses suggest that potential explanatory variables should have no meaningful effect on the outcome of interest. Without testing these hypotheses, empirical evaluation of theoretical arguments remains incomplete. Current practice in political science in this situation is to take a statistically insignificant effect as evidence for the research hypothesis, with an occasional discussion of whether or not the test has sufficient power. I explain that this procedure does not align with hypothesis testing conventions in political science and thus is prone to misinterpretations. In particular, a statistically insignificant effect is neither necessary nor sufficient to show that a variable has no meaningful effect. As an alternative, I introduce to political science the intersection-union method for creating tests, which allows researchers to quickly construct tests of hypotheses of no effect using already-available software.