dr. Irinel DRAGAN Professor of Mathematics Department of Mathematics, University of Texas at Arlington Arlington, Texas S.U.A. ----------------------------------- Average per capita formulas for Shapley values and semivalues ----------------------------------- ABSTRACT ----------------------------------- We introduce by an example the classical problem of fairly dividing the worth of the grand coalition. The Shapley value is one of the most popular solution. In 1981, Dubey-Neyman-Weber introduced axiomatically the Semivalues, which satisfy some of the axioms of the Shapley value, but the efficiency is lost. In 1992, we proved a so called Average per capita formula, which allows a parallel computation of the Shapley value. For a Semivalue we proved a similar formula in a joint paper with Martinez-Legaz, (2001), from which a similar algorithm can be derived. In the presentation, after introducing the two types of values, we show that the computation of the Semivalues by means of a Shapley value is possible. In fact, the Efficient normalization of a Semivalue is the Shapley value of a game obtained by rescaling from the given game. This is proved by means of the Average per capita formulas. Then, the Semivalue is reduced to the Shapley value by adding an additive game to the rescaled game. This gives another method for computing the Semivalues. What we call the Inverse problem can benefit from this relationship. SHORT CV ----------------------------------- Dr.Irinel Dragan is Professor of Mathematics at Department of Mathematics, University of Texas at Arlington, Texas, USA. His research focuses on Algebra, Geometry, and Game Theory. Dr.Dragan held a research and teaching position at University Al. I. Cuza (Iasi, Romania), Faculty of Mathematics until 1980. Dr.Dragan completed his PhD in 1961 at the University Al. I. Cuza (Iasi, Romania).