(with Kyle Hyndman), Review of Economic Studies74, 1125–1147, 2007.
Summary. We study coalition formation in “real time”, a situation in which coalition formation is intertwined with the ongoing receipt of payoffs. Agreements are assumed to be permanently binding: They can only be altered with the full consent of existing signatories. For characteristic function games we prove that equilibrium processes—whether or not these are history dependent—must converge to efficient absorbing states. For three-player games with externalities each player has enough veto power that a general efficiency result can be established. However, there exist four-player games in which all Markov equilibria are inefficient from every initial condition, despite the ability to write permanently binding agreements. Online Appendix.
in Abhijit Banerjee, Roland Benabou and Dilip Mookherjee, What Have We Learned About Poverty?, Oxford University Press, 2006.
Summary. Introduces the idea of aspirations as a socially determined reference point. The paper argues that reachable aspirations serve to inspire, while still higher aspirations could lead to frustration.
(with Joan Esteban), American Economic Review101, 1345–1374, 2011.
Summary. In this paper we study a behavioral model of conflict that provides a basis for choosing certain indices of dispersion as indicators for conflict. We show that a suitable monotone transform of the equilibrium level of conflict can be proxied by a linear function of the Gini coefficient, the Herfindahl-Hirschman fractionalization index, and a specific measure of polarization due to Esteban and Ray.
