On the H -Manipulability of Fuzzy Social Choice Functions Fouad Ben Abdelaziz ∗ , Jos´ e Figueira † , Olfa Meddeb ‡ October 1, 2005 * Institut Sup´ erieur de Gestion, Universit´ e de Tunis, 41, Rue de la libert´ e, Cit´ e Bouchoucha, Le Bardo 2000, Tunisie. Phone: (+216) 71 561 854, Fax: (+216) 71 568 767, E-mail: fabdelaz@sharjah.ac.ae † CEG-IST, Center for Management Studies, Instituto Superior T´ ecnico, Departamento de En- genharia e Gest˜ao, Office: 2N818, IST - Taguspark, Av. Prof. Cavaco Silva, 2780 - 990, Porto Salvo, Portugal, Phone: (+351) 214 233 507, Fax: (+351) 214 233 568, E-mail: figueira@ist.utl.pt ‡ Institut Sup´ erieur de Gestion, Universit´ e de Tunis, 41, Rue de la libert´ e, Cit´ e Bouchoucha, Le Bardo 2000, Tunisie. Phone: (+216) 71 561 854, Fax: (+216) 71 568 767, E-mail: Olfa.Meddeb@isg.rnu.tn i