The actions of different agents sometimes reinforce each other. Examples are network effects and the threshold models used by sociologists as well as Harvey Leibensteins's "bandwagon effects." We model such situations as a game with increasing differences, and show that tipping of equilibria,...

We survey the literature on social networks by putting together the economics, sociological and physics/applied mathematics approaches, showing their similarities and differences. We expose, in particular, the two main ways of modeling network formation. While the physics/applied mathematics...

We survey the literature on social networks by putting together the economics, sociological and physics/applied mathematics approaches, showing their similarities and differences. We expose, in particular, the two main ways of modeling network formation. While the physics/applied mathematics...

Most network games assume that the best response of a player is a linear function of the actions of her neighbors; clearly, this is a restrictive assumption. We developed a theory called sign-equivalent transformation (SET) underlying the mathematical structure behind a system of equations...

We investigate the role of conflicting interests in a boundedly rational model of belief dynamics. Individuals have different preferences about the action to take, are subject to persuasion bias and repeatedly communicate with their neighbors in a social network. They communicate strategically...

In the benchmark model of Bala and Goyal (2000) on network formation, the equilibrium network is asymmetric and unfair as agents have different payoffs. While they are prominent in reality, asymmetric networks do not emerge in the lab mainly because of fairness concerns. We extend this model...

The paper proposes a game of weighted network formation in which each agent has a limited resource to form links of possibly different intensities with other agents and to use for private purposes. We show that every equilibrium is either "reciprocal" or "non-reciprocal". In a reciprocal...

We study competitive behavior in all-pay Tullock (1980) contests with identity-dependent externalities (IDEs) governed by a fixed network. First, we introduce a model of network contest games, in which the prize generates an externality---which may be positive or negative---that impacts each...

We provide an overview and synthesis of the literature on how social networks influence behaviors, with a focus on diffusion. We discuss some highlights from the empirical literature on the impact of networks on behaviors and diffusion. We also discuss some of the more prominent models of...

In this chapter, I provide an overview of research on social networks and their role in shaping behavior and economic outcomes. I include discussion of empirical and theoretical analyses of the role of social networks in markets and exchange, learning and diffusion, and network games. I also...