The Sixth Annual International Symposium in Economic Theory and Econometrics was dedicated to Jacques Drèze on the occasion of his retirement. During his career, he worked on the development extension and applications of general equilibrium theory, and he also was essential to the founding of the Center for Operations Research and Econometrics (CORE) in Louvain-la-Neuve, Belgium. The papers in this volume are those given at the conference, and present some of the recent developments in general equilibrium theory in perspective of actual and potential applications.