First Author:   Maroš Servátka Department of Economics and Finance, University of Canterbury maros.servatka@canterbury.ac.nz   Private Bag 4800 Christchurch, 8140, New Zealand   +64-3-3642825 ext. 6825(Phone) +64-3-3642825 ext. 6825(Fax) http://www.econ.canterbury.ac.nz/people/servatka.shtml Second Author: Radovan Vadovič Centro de Investigación Económica, Instituto Tecnológico Autónomo de México rvadovic@itam.mx   Camino a Sta. Teresa 930, Colonia Héroes de Padierna México, D.F., 10700, Mexico   +52 55 56284000 ext. 2959(Phone)   http://allman.rhon.itam.mx/~rvadovic/