First Author:   Staffan Ringbom Swedish School of Economics and HECER staffan.ringbom@shh.fi   Department of Economics, Swedish School of Economics, P.O. Box 479 Helsinki, 00101, Finland       Second Author: Oz Shy University of Haifa and Swedish School of Economics ozshy@econ.haifa.ac.il   Department of Economics, University of Haifa Haifa, 31905, Israel       http://www.ozshy.com