Jan 25, 2013
With S. Nageeb Ali
Abstract: Which social norms and networks maximize cooperation in bilateral relationships? We study a network of players in which each link is a repeated bilateral partnership with two-sided moral hazard. The obstacle to community enforcement is that each player observes the behavior of her partners in their partnerships with her, but not how they behave in other partnerships. We introduce a new metric for the rate at which information diffuses in a network, which we call viscosity, and show that it provides an operational measure for how conducive a network is to cooperation. We prove that clique networks have the lowest viscosity and that the optimal equilibrium of the clique generates more cooperation and higher average utility than any other equilibrium of any other network. This result offers a strategic foundation for the perspective that tightly knit groups foster the most cooperation. We apply this framework to analyze favor exchange arrangements, decentralized trade in networked markets, and social collateral.
Working paper 10/31/2012
Tags: Repeated games, Social Networks, Community enforcement, Cooperation, Contagion, Cliques
Jan 16, 2012
With Kareen Rozen
Abstract: We study optimal contracting in teams with peer monitoring and moral hazard, featuring stylized aspects of production environments with complex tasks. Agents have many opportunities to shirk, task-level monitoring is needed to provide useful incentives, and because it is difficult to write individual performance into formal contracts, incentives are provided informally, using wasteful sanctions like guilt and shame, or slowed promotion.
These features give rise to optimal contracts with “empty promises” and endogenous supervision structures. Agents optimally make more promises than they intend to keep, leading to the concentration of supervisory responsibility in the hands of one or two agents.
Working paper 1/16/2012
Tags: Contracts, Moral hazard, Mechanism design, Peer monitoring, Partnership, Teams, Principal-Agent, Bounded memory, Cooperation
Sep 11, 2011
With Heidi Gjertsen, Theodore Groves, Eduard Niesten, Dale Squires, and Joel Watson
Abstract: We model conservation agreements using contractual equilibrium, a concept introduced by Miller and Watson (2010) to model dynamic relationships with renegotiation. The setting takes the form of a repeated principal-agent problem, where the principal must pay to observe a noisy signal of the agent's effort. Lacking a strong external enforcement system, the parties rely on self-enforcement for their relational contract. We characterize equilibrium play (including how punishments and rewards are structured) and we show how the parties' relative bargaining powers affect their ability to sustain cooperation over time. We argue that the model captures important features of real conservation agreements and reveals the ingredients required for successful agreements.
Working paper 9/23/2010 (stay tuned for an updated version in fall 2012)
Tags: Repeated games, Community enforcement, Conservation Agreements, Monitoring, Bargaining, Negotiation, Renegotiation, Principal-Agent, Cooperation, Forest Protection, Cambodia, Coral Reefs, Fiji, Sea Turtles, Solomon Islands, Grey Whales, Baja California
Jan 13, 2009
Note: Satoru Takahashi discovered an error in a previous version of this paper. I am working on figuring out how to correct it. For now, I am posting a shorter version that contains only the correct results. Please do not cite, circulate, or refer to any version of the paper dated prior to 2009.
Abstract: This paper proves folk theorems for repeated games with private information, communication, and monetary transfers, in which signal spaces may be arbitrary, signals may be statistically interdependent, and payoffs for each player may depend on the signals of other players.
Working paper 1/13/2009
Tags: Repeated games, Private information, Mechanism design, Folk theorem
