Partisanship as a social convention

Existing research models partisanship as a function of either running talli es of party performance evaluations or emotional identifications with parti es. However, these models are arguably insufficient to account for the vari ation in the propensity to act on behalf of a party. This article develops and tests a model of partisanship as a social convention. The decision to a ct on behalf of a party is modeled as an asymmetric n-person coordination g ame with multiple equilibria, where the payoffs from being coordinated on a cts of partisanship are higher than the payoffs from coordination on absten tion if the costs of those actions are sufficiently low. Given that such a coordination game will be easier to solve where acts of partisanship are mo re public, we should see a greater incidence of partisanship in states with laws providing for publicly available party registration, relative to stat es without such laws. The model is tested using data from the 1984-96 Ameri can National Election Studies merged with data on states' party registratio n laws. Several measures of partisanship are shown to be responsive to the presence of laws providing for party registration, controlling for other fa ctors known to affect the propensity to be partisan.