Ahmed sadek Sadek Yousuf Aix Marseille School of Economics   3rd floor, 3 rue de l'ancienne madeleine 4th floor Aix en Provence, Arkansas 13100 France   asyousuf@uark.edu   https://sites.google.com/view/ahmedsadekyousuf/home           JEL Areas: C4 : Econometric and Statistical Methods: Special Topics R : Urban, Rural, and Regional Economics