On uniqueness of coalitional equilibria

Michael Finus^a, Pierre von Mouche^b, Bianca Rundshagen<sup>c

a</sup> University of Bath, Department of Economics, Bath BA2 7AY, United Kingdom
^b Wageningen Universiteit, Hollandseweg 1, 6700 EW, Wageningen, The Netherlands
^c Universität Hagen, Department of Economics, Universitätsstrasse 11, 58097 Hagen, Germany

Abstract: For the so-called ‘new approach’ of coalition formation it is important that coalitional equilibria are unique. Uniqueness comes down to existence and to semi-uniqueness, i.e. there exists at most one equilibrium. Although conditions for existence are not problematic, conditions for semi-uniqueness are. We provide semi-uniqueness conditions by deriving a new equilibrium semi-uniqueness result for games in strategic form with higher dimensional action sets. The result applies in particular to Cournot-like games.

Keywords: Coalition formation, Cournot oligopoly, equilibrium (semi-)uniqueness, game in strategic form, public good.

Language: English