A Behavioral Model of Coalition Formation: The French Apparentements Of 1951

In: The journal of conflict resolution: journal of the Peace Science Society (International), Band 20, Heft 4, S. 563-588

Abstract

The 1951 elections for the French National Assembly permitted the formation of distinct formalized coalitions in each of 95 multimember districts. The resulting coalition outcomes are analyzed via a behavioral model that emphasizes real-time constraints that are largely ignored by formal game theory. Other major features of the model include: (1) coalitions are built incrementally and without defection until a coalition controls a majority of the votes; (2) offers to prospective partners are constrained by a graph that represents ideological and other constraints; (3) offers are made probabilistically, proportional to the votes controlled by the potential allies; (4) reciprocated offers are necessary and sufficient for a coalition to form. Estimated with data from districts with five or fewer coalescable parties or lists, the model is validated on districts with six parties or lists. The model has modest explanatory power, its major failure suggesting the influence of political forces at the national level that are beyond the scope of the district level model. Quite speculatively, these national forces may have been essential to preventing De Gaulle's coming to power in 1951. The model attests to both ideological and opportunistic facets of Fourth Republic politics.