E-mail address : e-shmaya@kellogg.northwestern.edu Kellogg School of Management, Northwestern University [16] John von Neumann and Oskar Morgenstern. Theory of games and economic behavior . Princeton Uni- versity Press, Princeton, NJ, 2004. Reprint of the 1980 edition [Princeton Univ. Press, Princeton, NJ; MR0565457]. 22