title: The convergence coefficient across political systems.
abstract: Formal work on the electoral model often suggests that parties or candidates should locate themselves at the electoral mean. Recent research has found no evidence of such convergence. In order to explain nonconvergence, the stochastic electoral model is extended by including estimates of electoral valence. We introduce the notion of a convergence coefficient, c. It has been shown that high values of c imply that there is a significant centrifugal tendency acting on parties. We used electoral surveys to construct a stochastic valence model of the the elections in various countries. We find that the convergence coefficient varies across elections in a country, across countries with similar regimes, and across political regimes. In some countries, the centripetal tendency leads parties to converge to the electoral mean. In others the centrifugal tendency dominates and some parties locate far from the electoral mean. In particular, for countries with proportional electoral systems, namely, Israel, Turkey, and Poland, the centrifugal tendency is very high. In the majoritarian polities of the United States and Great Britain, the centrifugal tendency is very low. In anocracies, the autocrat imposes limitations on how far from the origin the opposition parties can move.
authors.affiliation: Center in Political Economy, Washington University, 1 Brookings Drive, Saint Louis, MO 63130, USA ; Department of Economics, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON, Canada N2L 3C5.
authors.forename: Maria
authors.initials: M
authors.lastname: Gallego
authors.affiliation: Center in Political Economy, Washington University, 1 Brookings Drive, Saint Louis, MO 63130, USA.
authors.forename: Norman
authors.initials: N
authors.lastname: Schofield
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003657:Decision Making; D003661:Decision Support Techniques; D015233:Models, Statistical; D011057:Politics; D013269:Stochastic Processes