Displaying 13 Items
October 2010.
Summary. This paper studies costly conflict in a world of complete information, in which society can commit to divisible transfers among all potentially warring groups. The difficulty in preventing conflict arises from the possibility that there may be several conflictual divisions of society, each based on a different marker, such as class, geography, religion, or ethnicity.
(with Anirban Mitra), in Advances in the Economics of Religion (J-P Carvalho, S. Iyer and J. Rubin, eds.) Volume 158, International Economic Association Series, Palgrave Macmillan (2019).
Summary. We revisit and extend the core issues studied in Mitra and Ray (2014). The main reason behind this retrospection is to check if the robust empirical patterns recorded there persist once we consider a longer time frame extending into the 21st century. We make three observations: (i) There is a clear economic component to violence, roughly along the lines of our earlier paper; (ii) There is a new aspect which is assuming salience now — namely, a strong political component which is manifesting itself through the presence of BJP legislators; (iii) Ahmedabad exemplifies the ascendancy of this political component.
(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.
(with Joan Esteban), American Economic Review 101, 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.
unpublished manuscript, June 2009.
Summary. This paper studies costly conflict in a world of complete information, in which society can commit to divisible transfers among all potentially warring groups. The difficulty in preventing conflict arises from the possibility that there may be several conflictual divisions of society, each based on a different marker, such as class, geography, religion, or ethnicity. It is shown that this diversity of societal markers is particularly conducive to social instability when potential conflict is over private, divisible resources. In contrast, when conflict is over public goods, such diversity promotes social stability.
(with Francis Bloch and Garance Genicot), American Economic Review 97 (Papers and Proceedings), 65–69, 2007.
Summary. Based on our earlier work on risk sharing in groups and networks (Garance Genicot and Debraj Ray, 2003, 2005 and Francis Bloch, Garance Genicot and Debraj Ray, 2006), this paper proposes a simple model of mutual help in groups and networks. We argue that, if social capital can promote cooperation among groups of individuals, it can also hurt it. When groups of individuals can jointly deviate from a social norm, the fact that they have built strong ties among themselves may in fact make deviations easier, and weaken cooperation in society as a whole.
(with Kfir Eliaz and Ronny Razin), American Economic Review 96, 1321-1332, 2006.
Summary. The phenomenon of choice shifts in group decision-making has received much attention in the social psychology literature. Faced with a choice between a “safe” and “risky” decision, group members appear to move to one extreme or the other, relative to the choices each member might have made on her own. Both risky and cautious shifts have been identified in different situations. This paper demonstrates that from an individual decision-making perspective, choice shifts may be viewed as a systematic violation of expected utility theory. We propose a model in which a well-known failure of expected utility — captured by the Allais paradox — is equivalent to a particular configuration of choice shifts. Thus, our results imply a connection between two well-known behavioral regularities, one in individual decision theory and another in the social psychology of groups.
(with Joan Esteban), European Economic Review 44, 694-705, 2000.
Summary. We formalize a model in which individuals lobby before the government in order to bene”t from some productivity-enhancing government action (infrastructures, direct subsidies, permissions, in short). The government honestly tries to allocate these permissions to the agents that will make the best use of them, as revealed by the intensity of their lobbying. If the marginal cost of resources varies with wealth, the amount of information transmitted through lobbying will depend on the degree of inequality. In this paper, we summarize the main approach and examine the special case of equal wealth. We show that the nature of signaling equilibria is critically a!ected by per-capita wealth.
(with Kaoru Ueda), Journal of Economic Theory 71, 324-348, 1996.
Summary. A group of agents is collectively engaged in a joint productive activity. Each agent supplies an observable input, and output is then collectively shared among the members according a social welfare function. However, individual actions are taken on a selfish basis, and the collective decision is only made after inputs are chosen. This leads to inefficiency. The aim of this paper is to show formally that, contrary to popular belief, the degree of inefficiency decreases in the extent of egalitarianism embodied in the social welfare function.
(with Kalyan Chatterjee, Bhaskar Dutta and Kunal Sengupta), Review of Economic Studies 60, 463-477, 1993.
Summary. We explore a sequential-offers model of n-person coalitional bargaining with transferable utility and with time discounting. Our focus is on stationary equilibria of the resulting non-cooperative game. Efficient stationary equilibria converge to a point in the core as the discount factor approaches 1. For strictly convex games, this is the egalitarian solution of Dutta and Ray (Econometrica 1989).
(with Bhaskar Dutta), Games and Economic Behavior 3, 403-422, 1991.
Summary. This paper proposes a constrained egalitarian solution concept for TU games which combines commitment for egalitarianism and promotion of individual interests in a consistent manner. The paper shows that the set of constrained egalitarian allocations is nonempty for weakly superadditive games. The solution is “almost” unique if the desirability relation between players is complete.
(with Bhaskar Dutta), Econometrica 57, 615-635, 1989.
Summary. We introduce a new solution concept for transferable-utility games in characteristic function form, when individuals collectively believe in equality as a desirable social goal, although in their private actions they behave selfishly. This latter consideration implies that an “egalitarian solution” must satisfy core-like participation constraints, while the former implies that such a solution is also a Lorenz-maximal element of the constrained set. Despite the well-known fact that the Lorenz ordering is incomplete, we show that the egalitarian solution is unique whenever it exists.
(with Bhaskar Dutta, Kunal Sengupta and Rajiv Vohra), Journal of Economic Theory 49, 93-112, 1989.
Summary. Both the core and the bargaining set fail to satisfy a natural requirement of consistency. In excluding imputations to which there exist objections, the core does not assess the “credibility” of such objections. The bargaining set goes a step further. Only objections which have no counter-objections are considered justified. However, the credibility of counter-objections is not similarly assessed. We formulate a notion of a consistent bargaining set in which each objection in a “chain” of objections is tested in precisely the same way as its predecessor. Various properties of the consistent bargaining set are also analyzed.