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Lecture series are sponsored by

Prof. Brian W. Rogers (Washington University in St. Louis)

Abstract: We study how cooperation may be sustained in anonymous, evolving networks. Individuals form relationships under a matching protocol and engage in prisoner's dilemma interactions with their partners. We characterize a class of equilibria that supports cooperation as a stationary outcome. When cooperation is possible, its level is uniquely determined. The key mechanism is that the endogenous network dynamics allow an individual to gradually accumulate a neighbourhood of profitable partnerships through cooperation, whereas defection results in marginalization. Even as players become patient, equilibrium allows for full cooperation, only autarky, or the coexistence of cooperation and defection, depending on payoffs. This captures, in particular, the observation that many large systems are characterized by a high, though less than universal, level of cooperation. Smaller levels of cooperation can be sustained only through exclusivity among cooperating agents, showing the reliance of strategic behaviour on norms surrounding relationship formation. This is joint work with Brendan Lucier and Nicole Immorlica

Short Bio: Brian Rogers is an Associate Professor in Economics at Washington University in St. Louis, where he also directs the Missouri Social Science Experimental Laboratory (MISSEL). Prof. Rogers received his Ph.D. from Caltech in 2006 and was on the faculty in Managerial Economics and Decision Sciences (MEDS) at the Kellogg School of Management at Northwestern University from 2006-2013, before moving to Wash U. His research is broadly in microeconomic theory and game theory, with a particular emphasis on the role of networks and social interactions in strategic models. Recent work includes incorporating incentives into epidemiological diffusion models, as well as understanding the coevolution of partner choices and repeated play in social models of games.