Linear efficient and symmetric values for TU-games: sharing the joint gain of cooperation

Two well-known single valued solutions for TU-games are the Shapley value and Solidarity value, which verify three properties: Linearity, Symmetry and Efficiency, and the null player axiom. On the other hand, the interpretation of the two values is usually related on the marginal contribution of a player that joins a coalition. The paper generalizes the approach. First, the marginal contribution concept is extended to any valued solution that satisfies the three properties. Second, the null player axiom is also generalized and it is shown that any single valued solution satisfying the three properties is uniquely characterized by a null player axiom. In particular, the paper provides new interpretations, in the sense of marginal contribution, for other well-known single values such as Egalitarian value and Consensus value and also offers the opportunity for recasting in extensive form some well-established results.