David Schmeidler

David Schmeidler (1939 – 17 March 2022) was an Israeli mathematician and economic theorist. He was a Professor Emeritus at Tel Aviv University and the Ohio State University. David Schmeidler was born in 1939 in Kraków, Poland. He spent the war years in Russia and moved back to Poland at the end of the war and to Israel in 1949. From 1960 to 1969 he studied mathematics at the Hebrew University of Jerusalem (BSc, MSc, and PhD), the advanced degrees under the supervision of Robert Aumann. He visited the Catholic University of Louvain and University of California at Berkeley before joining Tel-Aviv University in 1971, holding professorships in statistics, economics, and management. He held a part-time position as professor of economics at the Ohio State University since 1987. Schmeidler died on 17 March 2022. Schmeidler's early contributions were in game theory and general equilibrium theory. He suggested a new approach to solving cooperative games – the nucleolus – based on equity as well as feasibility considerations. This concept, originating from Schmeidler's PhD dissertation, was used to resolve a 2000 years old problem. Robert Aumann and Michael Maschler, in a paper published in 1985, showed that a conundrum from the Babylonian Talmud, which defied scholars’ attempts at comprehension over two millennia, was naturally resolved when applying the concept of the nucleolus. Schmeidler also pioneered the study of non-atomic strategic games, in which each player has negligible impact on the play of the game, as well as the related concept of “congestion games”, where a player's payoff only depends on the distribution of the other players’ strategic choices (and not on individual choices). Schmeidler has made many other contributions, ranging from conceptual issues in implementation theory, to mathematical results in measure theory. But his most influential contribution is probably in decision theory. Schmeidler was the first to propose a general-purpose, axiomatically-based decision theoretic model that deviated from the Bayesian dictum, according to which any uncertainty can and should be quantified by probabilities.