1. 1 Higher School of Management – Tlemcen – MIFMA laboratory , Algeria
2. 2 University Centre of Maghnia , Tlemcen , Algeria ; e-mail: a_hichem210@hotmail.fr
3. 3 Djillali Liabes University of Sidi Bel Abbes , Department of Economics , Algeria
4. 4 Djillali Liabes University of Sidi Bel Abbes , Department of Economics , Algeria ; e-mail: mohammed.dahmani@univ-sba.dz