Downs and Two-Party Convergence

▪ Abstract We take as our starting point the insights of Downs (1957) into two-party competition. A careful reading of Downs offers a much more sophisticated and nuanced portrait of the factors affecting party differentiation than the simplistic notion that, in plurality elections, we ought to expect party convergence to the views of the median voter. Later scholars have built on Downsian ideas to see what happens vis-à-vis party differentiation when we modify key assumptions found in the basic Downsian spatial model. Recent work allows us to turn what is taken to be the Downsian view on its head: Although there are pressures in two-party competition for the two parties to converge, in general we should expect nonconvergence. Moreover, contra the negative portrait offered by Green & Shapiro (1994) of the limited or nonexistent value of research on party competition models in the Downsian tradition, we argue that, when viewed as a whole, neo-Downsian models—especially those of the past decade—do allow us to reconcile theory and data in terms of a multi-componented theory of party competition with testable implications for comparative statics.