2025 Zayira Ray
Julius Silver Professor, Faculty of Arts and Science,
Professor of Economics, New York University
Research Associate, NBER
Part-Time Professor, University of Warwick
Research Fellow, CESifo
Spool Member, ThReD

Department of Economics
New York University,
19 West 4th Street
New York, NY 10012, U.S.A.
debraj.ray@nyu.edu, +1 (212)-998-8906.

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Oxford University Press, 2008. This book is now open-access; feel free to download a copy, and to buy the print version if you like the book.
Three Randomly Selected Papers
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Internally-Negotiation-Proof Equilibrium Sets: Limit Behavior for Low Discounting

Games and Economic Behavior 6, 162-177, 1994.

Summary. Recent literature in the theory of dynamic games addresses renegotiatioin-proof equilibria, For repeated games, I analyze the limit of renegotiation-proof equilibrium sets as discounting vanishes. The main result states that such limit sets must either be singletons or belong to the Pareto frontier of the convex hull of the feasible set of the stage game payoffs.

Inefficiency and the Golden Rule: Phelps-Koopmans Revisited

(with Tapan Mitra), in Sugata Marjit and Meenakshi Rajeev (eds), Emerging Issues in Economic Development: A Contemporary Theoretical Perspective: Essays in Honour of Dipankar Dasgupta & Amitava Bose, Oxford University Press, 2012.

Summary. We study the celebrated Phelps-Koopmans theorem in environments with nonconvex production technologies. We argue that a robust failure of the theorem occurs in such environments. Specifically, we prove that the Phelps-Koopmans theorem must fail whenever the net output of the aggregate production function f(x), given by f(x) − x, is increasing in any region between the golden rule and the maximum sustainable capital stock.

 

Coalition Formation

(with Rajiv Vohra),  in Handbook of Game Theory Vol 4 (H.P. Young and S. Zamir, eds), Elsevier North Holland, 2014.

Summary. This chapter surveys a sizable and growing literature on coalition formation. We refer to theories in which one or more groups of agents (“coalitions”) deliberately get together to jointly determine within-group actions, while interacting noncooperatively across groups. The chapter describes a variety of solution concepts, using an umbrella model that adopts an explicit real-time approach. Players band together, perhaps disband later and re-form in shifting alliances, all the while receiving payoffs at each date according to the coalition structure prevailing at the time. We use this model to nest two broad approaches to coalition formation, one based on cooperative game theory, the other based on noncooperative bargaining. Three themes that receive explicit emphasis are agent farsightedness, the description of equilibrium coalition structures, and the efficiency implications of the various theories.