First Author:   Khaled Guesmi Department of Finance, IPAG Business School, IPAG Lab & EconomiX, University of Paris West, France khaled.guesmi@ipag.fr         Second Author: Mohamed Hedi Arouri EDHEC Business School mohamed.arouri@u-clermont1.fr         Third Author: Ilyes Abid EconomiX, UMR CNRS 7166, University of Paris West, La Defense ilyes.abid@gmail.com         Fourth Author: Frédéric Teulon Department of Finance, IPAG Business School, IPAG Lab, France f.teulon@ipag.fr         http://