First Author:   Jacques Silber Bar-Ilan University jsilber_2000@yahoo.com   Raanana, 43414, Israel   0549327554(Phone) 0549327554(Fax) Second Author: Joseph Deutsch Bar-Ilan University jdeutsch@biu.ac.il   Department of Economics, Bar-Ilan University Ramat-Gan, 52900, Israel