The position value for union stable systems

In this paper, we study the position value for games in which partial cooperation exist, that is based on a union stable coalition system. The concept of basis is introduced for these systems, allowing for a de...nition of the position value. Moreover, an axiomatic characterization of the position value is provided for a speci...c class of union stable systems. Conditions under which convexity is inherited from the underlying game to the conference game, and the position value is a core vector of the restricted game are provided. 1991 Mathematics Subject Classi...cation: 90D12