An alternative characterization of the weighted Banzhaf value

We provide a new characterization of the weighted Banzhaf value derived from some postulates in a recent paper by Radzik, Nowak and Driessen 7]. Our approach owes much to the work by Lehrer 4] on the classical Banzhaf value based on the idea of amalgamation of pairs of players and an induction construction of the value. Compared with the approach in 7] we consider two new postulates: a weighted version of Lehrer’s “2-efficiency axiom” 4] and a generalized “null player out” property studied in terms of symmetric games by Derks and Haller 2]. Received: December 1997/final version: October 1999