First Author:   Serge Rey CATT-University of Pau and Pays de l''Adour serge.rey@univ-pau.fr   Department of Economics, C.A.T.T,, Avenue du Doyen Poplawski, B.P. 1633, 64016 Pau Cedex PAU, France       http://catt.univ-pau.fr/live/presentation/Equipe/Serge_Rey