Andreu Mas-Colell, 1944-

Andreu Mas-Colell is one of the leading Neo-Walrasian theorists of the modern day. His work - often characterized as a powerful testament to the value of worked examples and counter-examples - has led to a collection of remarkable insights and the opening of new avenues for General Equilibrium Theory.

The story begins in 1974, when Andreu Mas-Colell proved the existence of a competitive equilibrium after dropping the famous axioms of completeness and transitivity of consumer preferences. He liked this so much that he and David Gale did it again in 1975.  Mas-Colell has since directed his efforts into several particularly important areas: in the exploitation of differentiable calculus to analyse G.E.T. (e.g. 1977, 1985), the use of cross-dual dynamics to examine stability of equilibrium (1986), the examination of market demand and aggregation (1976, 1977, 1987) and the theory of differentiated commodities (1975).

Perhaps most famously, Mas-Colell has explored the conditions necessary for the existence of an equilibrium in a wide variety of infinite-dimensional contexts - whether for Walrasian competitive equilibria (1986, 1991), Nash equilibria (1984) or Radner equilibria (1996). Indeed, his 1986 proof of existence of a Walrasian equilibrium in a rather generic infinite-dimensional economy has been hailed as definitive (although his introduction of "uniform properness" has been an issue of concern ever since). 

Mas-Colell is also renowned for his work on relating game theory to Walrasian G.E. - notably, in the relationship of the bargaining set with competitive equilibrium (1989) and exploring the relationship between Walrasian and Nash equilibria (1981, 1983).  Mas-Colell is also one of the co-authors of  what is easily the modern textbook on microeconomic theory (1995).

Mas-Colell was born in Barcelona in Catalonia, Spain.  As an undergraduate, he was expelled from the University of Barcelona in the 1960s for democratic activism, finally obtaining his undergraduate degree in 1966 at the University of Valladolid.  In 1968, he went to the United States, getting a Ph.D in economic from the University of Minnesota in 1972.  He went immediately to the University of California, Berkeley (obtaining a joint appointment with the mathematics department in 1975).  He was lured by Harvard in 1981.   He returned to Spain in 1995, becoming a professor at the University Pompeu Fabra in Barcelona.  He has also since gotten involved in politics, entering the Catalonian Parliament under the parliamentary group Convergència i Unió and is serving as its Commissioner on Universities and Research.

Major Works of Andreu Mas-Colell

• "Algunas Observaciones sobre la Teoria del Tatonnement de Walras en Economias Productivas", 1974, Annales de Economia
• "An Equilibrium Existence Theorem without Complete or Transitive Preferences", 1974, JMathE.
• "A Note on a Theorem of F. Browder", 1974, Mathematical Programming.
• "An Equilibrium Existence Theorem for a General Model without Ordered Preferences", with D. Gale, 1975, JMathE.
• "A Model of Equilibrium with Differentiated Commodities", 1975, JMathE.
• "On the Continuity of Equilibrium Prices in Constant-Returns Production Economies", 1975, JMathE.
• "The Demand Theory of the Weak Axiom of Revealed Preference", with Kihlstrom and Sonnenschein, 1976, Econometrica.
• "A Remark on the Smoothing Property of Convex, Complete Preorders", 1976, JMathE
• "Indivisible Commodities and General Equilibrium Theory", 1977, JET.
• "On the Equilibrium Price Set of an Exchange Economy", 1977, JMathE.
• "The Recoverability of Consumer Preferences from Market Demand Behavior", 1977, Econometrica
• "Regular Nonconvex Economies", 1977, Econometrica
• "Some Generic Properties of Aggregate Excess Demand and an Application" with W.M. Neuefeind, 1977, Econometrica
• "A Note on the Core Equivalence Theorem: how many blocking coalitions are there?", 1978, JMathE
• "A Refinement of the Core Equivalence Theorem", 1979, Economics Letters
• "Noncooperative Approaches to the Theory of Perfect Competition: Presentation", 1980, JET
• "Efficiency of Cournot-Nash Equilibria in Strategic Market Games" with P. Dubey and M. Shubik, 1980.
• "Efficiency Properties of Strategic Market Games: An Axiomatic Approach" P. Dubey and M. Shubik, 1980, JET
• "The Cournotian Foundations of Walrasian Equilibrium Theory: An exposition of recent theory", 1981, in Hildenbrand, editor, Advances in Economic Theory
• "Walrasian equilibria as Limits of Noncooperative Equilibria: Part I - mixed strategies", 1983, JET
• "On a Theorem by Schmeidler", 1984, JMathE
• "Pareto Optima and Equilibria: the finite-dimensional case", 1985, in Aliprantis et al, editors, Advances in Equilibrium Theory
• The Theory of General Economic Equilibrium: A differentiable approach, 1985.
• "The Price Equilibrium Existence Problem in Topological Vector Lattices", 1986, Econometrica.
• "Valuation Equilibrium and Pareto Optimum Revisited", 1986, in Hildenbrand and Mas-Colell, editors, Contributions to Mathematical Economics.
• "Notes on Price and Quantity Tatonnement Dynamics", 1986, in Hildenbrand, editor, Models of Economic Dynamics.
• "Engel Curves Leading to the Weak Axiom in the Aggregate" with X. Freixas, 1987, Econometrica
• "An Example of Pareto Optima and Core Allocations far from Agents' Demand Correspondences", with R.M. Anderson, 1988, Econometrica
• "An Equivalence Theorem for a Bargaining Set", 1989, JMathE.
• "Real Indeterminacy with Financial Assets", with J. Geanakoplos, 1989, JET
• "A Geometric Approach to a Class of Equilibrium Existence Theorems", with M. Hirsch and M. Magill, 1990, JMathE
• "A New Approach to the Existence of Equilibria in Vector Lattices", with S.F. Richard, 1991, JET.
• "Equilibrium Theory in Infinite Dimensional Spaces", with W.R. Zame, 1991, in Hildenbrand and Sonnenschein, editors, Handbook of Mathematical Economics, Vol. IV.
• "On the Finiteness of the Number of Critical Equilibria: with an application to random selections", with J. Nachbar, 1991, JMathE
• "Infinite-Dimensional Equilibrium Theory: Discussion of Jones", 1992, in Laffont, editor, Advances in Economic Theory
• "Stationary Markov Equilibria" with D. Duffie, J. Geananakoplos, A. McLennan, 1994, Econometrica
• Microeconomic Theory, with M.D. Whinston and J.R.Green, 1995.
• "Existence of Securities Market Equilibrium with a Non-atomic State Space", with W.R. Zame, 1996, JMathE
• "Self-Fulfilling Equilibria: An existence theorem for a general state space", with P.K. Monteiro, 1996, JMathE

Resources on Andreu Mas-Colell

• HET Pages: Walrasian General Equilibrium Theory: incomplete and intransitive preferences, infinite commodities, incomplete markets
• Personal Webpage of Andreu Mas-Colell
• Mas-Colell Page at University Pompeu Fabra.
• Citation on Mas-Colell's induction into NAS
• Mas-Colell receives honorary doctorate from Univ. Alicante
• Mas-Colell in the Catalonian Parliament!
• Mas-Colell in the Commission of Univeristies and Research in Catalonia
• Mas-Colell on the transformation of Catalonia
• Mas-Colell in the news: (1), (2), (3), (4), (5), (6), (7)