Donald J. Brown, born on April 16, 1937 is a Professor for the Department of Economics at Yale University. Dr. Brown obtained his Ph.D. in mathematics from the Stevens Institute of Technology, and prior to that completed a Masters in physics at Pennsylvania State, and a B.A. in physics from the University of Colorado. His areas of interests when it comes to research are finance, econometrics, and microeconomic theory. Dr. Brown’s tenure at Yale University dates to 1971, where he has held several positions such as Professor in Economics and Mathematics, Chairman of the Economics Department, and Director of Undergraduate Studies for the Economics Department. In this time, he has been decorated with numerous scholarships, awards and honors. He has inspired both the academic and research community in economics through his vast number of publications.
For his first publication, Dr. Brown teamed up with Abraham Robinson, a great mathematician. Robinson assisted him in representing the concept of perfect competition by an economy with a nonstandard number of infinitesimal agents. In lemans terms, it means a number larger than zero, but smaller than any positive number on the number line. Dr. Brown added value to the research in non-standard equilibrium economics by demonstrating that a non-standard equilibrium is identical to the nonstandard core of large exchange economies. His paper Testable Restrictions on the Equilibrium Manifold, co-authored by Rosa Matzkin, gave birth to an entirely new field which has opened the topic to be researched by many subsequent scholars. The two presented a system of inequalities that include observations on market prices, individual incomes and aggregate endowments that must be satisfied to be consistent with the equilibrium behavior of a pure trade economy. This paper emphasizes the characterization of consumer behaviour given aggregate endowments and market prices that further justifies the theories behind a Robinson Crusoe economy.
In response to the work of Hugo Sonnenschein Rolf Mantel and Gerard Debreu, demonstrating that no significant behavior implied by individual utility maximization is preserved in the aggregate, Dr. Brown and Chris Shannon exhibited even further negative results on the implications of the Walrasian model. Their evidence showed that a data set within finite limits can never be used to prove the hypothesis that equilibria are locally unique or locally stable. This also proved that equilibrium comparative statics are locally monotone.
Lastly, his paper on incomplete markets with Peter DeMarzo and Curtis Eaves is widely renown as an influential publication of research. The challenged statement was, that in equilibrium models with incomplete markets, demand functions are not continuous at prices for which a marketed asset becomes redundant. On the contrary Brown DeMarzo and Eaves demonstrated that this discontinuity is resolved, if a new asset is introduced when such redundancies occur. This assumption allowed them to prove generic existence, and also compute equilibria in the general equilibrium in the incomplete markets scenario. The applications of this paper allow for easier computations of equilibrium in the GEI model, which provides insight on behaviour of consumption and investment.
Through his publications, honours, and charitable contributions to the economic research community and Economics Faculty at Yale University, Dr. Brown is reputed as an approachable, humble and influential icon. In considering the accomplishments throughout Dr. Brown’s career, the Laurier Economics Club is honoured to share his biography, and shine a light to the immensity his work has had in the field of microeconomic theory.
Written by Joseph Vidi, Co-VP of Academics on the Laurier Economics Club