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.

Or use navbar and search icon at the top of this page to look for specific research areas and papers.
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
⟳ Re-randomize

Collective Action and the Group Size Paradox

(with Joan Esteban), American Political Science Review  95, 663–672, 2001.

Summary. According to the Olson paradox, larger groups may be less successful than smaller groups in furthering their interests. We address the issue in a model with three distinctive features: explicit intergroup interaction, collective prizes with a varying mix of public and private characteristics, and nonlinear lobbying costs. The interplay of these features leads to new results. When the cost of lobbying has the elasticity of a quadratic function, or higher, larger groups are more effective no matter how private the prize. With smaller elasticities, a threshold degree of publicness is enough to overturn the Olson argument, and this threshold tends to zero as the elasticity approaches the value for a quadratic function. 

Nash Bargaining in Coalitional Games

(with Rajiv Vohra). April 2025. Supplementary Notes.

Summary. We revisit Nash’s axiomatic approach to bargaining when both individuals and coalitions of individuals have outside options. As in Nash, our solution maximizes a (possibly weighted) product of payoffs net of individual disagreements, but coalitional threats appear as conventional constraints that are not netted out. We embed this solution into a setting with cross-coalitional externalities, and develop a “Nash-in-Nash” theory of viable coalitional structures. Every coalition follows its coalitional Nash solution but interacts noncooperatively with other coalitions, leading to a recursive determination of both threats and solutions. We discuss applications to public goods provision, R&D coalitions, and cartels in oligopolistic competition. Finally, for transferable utility characteristic functions, we connect the coalitional Nash solution to a notion of “pragmatic egalitarianism.”

The Economics of Orchards: An Exercise in Point-Input, Flow-Output Capital Theory

(with Tapan Mitra and Rahul Roy), Journal of Economic Theory  53, 12-50, 1991.

Summary.  This paper is concerned with the qualitative properties of optimal intertemporal programs in a model of point-input flow-output capital theory, when future utilities are discounted. Under a mild condition on the flow-output vector, we establish that optimal programs for every discount factor and every initial state (other than a unique stationary optimal state) will exhibit non-convergence.