De nouveaux éclairages sur le théorème de Coase et la vacuité du coeur

This paper is a contribution to the literature which uses the theory of cooperative game in order to show the non validity of the Coase Theorem in a 3-player game. We examine new situations which give rise to the refinement of the conditions under which the core of a game with three players is (non)empty and put forward three main results. First, we demonstrate that the nonemptiness of the core depends on the liability rules and the allocation of rights. Second, we show that when the externality is non transferable, the core is nonempty if the polluter is not liable but also that the core is always nonempty when the negotiations over a pollution level require unanimity. We provide a counterexample of the nonemptiness of the core in all other situations. Third, we show that, if the externality is non transferable, then an agent who does not negotiate can nevertheless influence the outcome of the negociation.