Sylvain Sorin is a professor at the Université Pierre et Marie Curie and a member of the Institut de Mathématiques Jussieu-Paris Rive Gauche (Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7586). He was previously a professor at the Université L. Pasteur, Strasbourg, and the Université Paris X Nanterre. He was an affiliated member of the Département de Mathématiques, École Normale Supérieure, Paris; Laboratoire d'Econométrie, École Polytechnique, Palaiseau; and the Center for Game Theory in Economics, State University of New York at Stony Brook. He is a Fellow of the Econometric Society and was a charter member of the Game Theory Society.