First Author:   David Pérez-Castrillo Universitat Autonoma de Barcelona david.perez@uab.es   Dept. Economia e Historia Economica, Edificio B Bellaterra, 08193, Spain   34 935811405(Phone) 34 935811405(Fax) http://pareto.uab.es/dperez/ Second Author: David Wettstein Ben-Gurion University wettstn@bgu.ac.il   Dept. of Economics Beer-Sheva, 84105, Israel   972 86472291(Phone)   http://www.econ.bgu.ac.il/facultym/wettstn/main.htm