[1] IPAG Business Sch, 184 Blvd St Germain, F-75006 Paris, France
[2] EUI, Dept Econ, Via Piazzuola 43, I-50133 Florence, Italy
[3] Univ Pretoria, Dept Econ, ZA-0002 Pretoria, South Africa
[4] Soochow Univ, Ctr Adv Stat & Econometr, Suzhou, Peoples R China