The Adaptive Dynamics of Turnout

We present a dynamic model of turnout in which voters’ behavior in one election depends only on whether they voted in the last election and whether their party won. This assumption may be justified by assuming citizens satisfice or by assuming they adjust subjective beliefs about being pivotal in ways that depend on whether they voted and on the outcome of the election. Regardless of the individual-level mechanism, the assumption that prior voter turnout and prior electoral outcome affect current turnout has empirical support, and we show that it implies turnout dynamics that are in accord with observed dynamics in several countries. Thus, this assumption or something very much like it is a necessary feature of any model of turnout. The ensuing model meets a basic requirement of any turnout model, substantial steady-state turnout, and correctly predicts some counterintuitive dynamical features of aggregate turnout—including declining turnout despite close elections and nonmonotonic changes—following significant political events such as the (re)establishment of democracy or major wars.