Bilel Rahali University of Grenoble-Alpes, INRA, UMR 1215 GAEL   BP 47 GRENOBLE cedex 9, 38040 FRANCE   rahali_b@yahoo.fr   http://www.grenoble.inra.fr/           JEL Areas: C9 : Design of Experiments: General C7 : Game Theory and Bargaining Theory:General