A dynamic model of protocoalition formation in ideologicaln-space

Axelrod's (1970) notion of “connected coalition” is generalized to the N-dimensional case, and a simple but powerful model of coalition dynamics is put forth which generates connected coalitions with certainty in the unidimensional case and which usually, but not necessarily, gives rise to minimal winning coalitions. Political decision making is discussed at the levels of the group, organization, society, and supranational system. Unlike most other models in the coalition literature, the model presented: (a) is based on notions of ideological policy proximity rather than on notions such as least resources or zero-sum conflict; (b) posits a dynamic process of protocoalition formation which permits two actors to join in a (proto)coalition only when each is the other's most preferred partner; and (c) for sufficient information about the policy preferences/ideological views of the political actors, yields unique predictions as to which coalition can be expected to form.