Quasi-values on Sub-spaces of Games
Résumé
Quasi-values are operators satisfying all axioms of the Shapley value with the possible exception of symmetry. We introduce the characterization and extendability problems for quasivalues on linear subspaces of games, provide equivalence theorems for these problems, and show that a quasi-value on a subspaceQ is extendable to the space of all games iff it is extendable toQ+Sp{u} for every gameu. Finally, we characterize restrictable subspaces and solve the characterization problem for those which are also monotone.