John O. Ledyard

John O. Ledyard (born April 4, 1940) is an American economist, the Alan and Lenabelle Davis Professor of Economics and Social Sciences at the California Institute of Technology, where he has been teaching since 1986. Previous positions include Northwestern University, where he was the Sydney G. Harris Professor of Social Science, and Carnegie Mellon University. At Caltech, he was a Sherman Fairchild Distinguished Scholar (1977-78) and later was the Chairman of the Division of the Humanities and Social Sciences (1992-2002).
==Early life and education==
Ledyard was born on April 4, 1940, in Detroit, Michigan. He earned a bachelor’s degree in mathematics from Wabash College in 1963, and then masters and doctoral degrees in economics from Purdue University in 1965 and 1967, respectively. Chen, Y., & Palfrey, T. R. (2017). Introduction to the Special Issue of Games and Economic Behavior in honor of John O. Ledyard. Games and Economic Behavior, 100(101), 1-5. 
==Academic career==
He became an assistant professor of Economics at Carnegie-Mellon University in 1967, and then he moved to the Economics Department at Northwestern University in 1969. He was the Sydney G. Harris Professor of Social Sciences at Northwestern until he moved permanently to the Division of the Humanities and Social Sciences at the California Institute of Technology in 1985. He had previously visited Caltech as the Sherman Fairchild Distinguished Scholar during the 1977–78 academic year. he later served as Chairman of the Division of the Humanities and Social Sciences (1992–2002), and currently holds the Alan and Lenabelle Davis Professor of Economics and Social Sciences.
==Research==
Ledyard's primary research is on the theoretical foundations and the applications of mechanism design of organizations. . He has contributed to our understanding of the roles of incentives and information in organizations. His theoretical work has provided insights into what is possible and what is not in the design of incentive-compatible organizations and voting systems. His more applied work has included the design and development of computer-assisted markets for trading pollution rights, acquiring logistics contracts, swapping portfolios of thinly traded securities, prediction markets, and advertising time. His current research includes the design of market-based approaches for managing spacecraft and instrument design (approaches designed to reduce cost-overruns and improve the science recovered), and the design of cap and trade systems for the control over-fishing and creating sustainable fisheries. Chen, Y., & Palfrey, T. R. (2017). Introduction to the Special Issue of Games and Economic Behavior in honor of John O. Ledyard. Games and Economic Behavior, 100(101), 1-5.
This section is organized into four distinct parts, as a reflection of the broad range of his research contributions: Mechanism Design; Voting and Elections; Public Goods and Cooperation; and Information Aggregation. Much of his research on public goods, for example, has been very influential in the development of mechanism design theory. His work on information aggregation also has substantial overlap with market design, a key subfield of mechanism design. His political science work on voter turnout addresses classic free-rider incentive problems of public good provision but in the context of electoral competition. While he is widely known and admired as a theorist, his impact in experimental economics is nearly as impressive.
===Mechanism Design===
Ledyard made seminal contributions to the filed of mechanism design. He is most well known for the Groves–Ledyard mechanism (Groves and Ledyard, 1977a), where Groves and Ledyard propose a mechanism in an environment with public goods, whose Nash equilibria are Pareto efficient. 
In Ledyard (1986), he explores the properties of mechanisms that must be incentive compatible for a broad range of priors. 
In Krajbich et al., 2009), Ledyard and his co-authors use physical measurements of the brain to augment standard mechanisms for eliciting valuations of public goods. 
Ledyard has a longstanding research interest in the design of mechanisms without side payments, and the relationship between efficiency and equilibrium, depending on whether transfers are feasible. Examples include Ledyard et al. (1996, 1997), Groves and Ledyard (1977b, 1977c), and Ledyard and Palfrey (1994, 2002). 
===Voting and Elections===
Ledyard's pioneering work applying Bayesian game theory to voting and candidate competition (Ledyard, 1984) was the start of a major development in formal political theory: the explicit modeling of private information in political games. It is now mainstream and leading approach in the field. 
===Public Goods and Cooperation===
Ledyard has made significant contributions to the theory of public goods. Of his seminal contributions to the theoretical public goods literature, Groves and Ledyard (1977a) characterize a family of Nash-efficient public goods mechanisms, and in doing so, move the theoretical mechanism design literature from impossibility (using the dominant strategy as the solution concept) to positive results, all of which preserve efficiency at the cost of non-manipulability. 
In addition to mechanism design under complete information, he has made fundamental contributions to Bayesian games (Ledyard, 1986) and Bayesian mechanism design (Ledyard and Palfrey, 1994, 2007). Using this Bayesian mechanism design approach, 
More than three decades before the modern development of the social preference literature in behavioral economics, he analyzed resource allocation in unselfish environments (Ledyard, 1968, 1971). 
===Information Aggregation===
An area of his applied mechanism design work is Information Aggregation. He is among the first to implement prediction markets to help corporations and governments improve decisions (Hanson et al., 2003). 
==Honors==
Professor Ledyard’s list of honorary distinctions and service includes an Honorary Degree from Purdue University and being a Fellow of the Econometric Society, a Fellow of the American Academy of Arts and Sciences, a Fellow of the Public Choice Society, and a Fellow of the Society for the Advancement of Economic Theory. He has served on several editorial boards of economics and public choice journals, on advisory committees to the National Science Foundation and other organizations, and as the President of the Public Choice Society.
His research has received numerous recognitions including election as a Fellow of the Econometric Society (1977), a Fellow of the American Academy of Arts and Sciences (1999), a Fellow of the Public Choice Society (2004), and a Fellow of the Society for the Advancement of Economic Theory (2011). 
Beyond his many research and teaching contributions, he has served on several editorial boards of economics and public choice journals, on advisory committees to the National Science Foundation and other organizations, and as the President of the Public Choice Society. In particular, he is one of the founding members of the Game Theory Society and has served as a Special Issue Editor for Games and Economic Behavior.
Category:American people
Category:American economists
Category:1940 births