1. School of Commerce; Senshu University; 2-1-1 Higashimita, Tama-ku Kawasaki Kanagawa 214-8580 Japan
2. Departamento Fundamentos del Análisis Económico; Universidad Rey Juan Carlos; P° Artilleros 28032 Madrid Spain
3. Toulouse School of Economics; Université Toulouse 1 Capitole; Aile Jean-Jacques Laffont, 21 allée de Brienne F-31015 Toulouse France