The novelty of our model is to combine models of collective action on networks with models of social learning. Agents are connected according to an undirected graph, the social network, and have the choice between two actions: either to adopt a new behavior or technology or stay with the default...

We develop a model of information exchange through communication and investigate its implications for information aggregation in large societies. An \textit{underlying state} determines payoffs from different actions. Agents decide which others to form a costly \textit{communication link} with,...

We develop a dynamic framework of strategic information transmission through cheap talk in a social network. Privately informed agents have different preferences about the action to be implemented by each agent and repeatedly communicate with their neighbors in the network. We first characterize...

We introduce a simple two-stage game of endogenous network formation and information sharing for reasoning about the optimal design of social networks like Facebook or Google+. We distinguish between unilateral and bilateral connections and between targeted and collective information sharing....

A distinctive feature of recent revolutions was the key role of social media (e.g. Facebook, Twitter and YouTube). We study the role of social media in mobilization. In a simple model we assume that while social media allow to observe all previous decisions, mass media only give aggregate...

Agents on a network experiment repeatedly, and simultaneously with the aim of choosing the optimal (uncertain) action between two alternatives. If each agent is forward looking and rational and observes the behavior only of those in his reference group, could different opinions emerge...

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...

There are many situations in which a customer's proclivity to buy the product of any firm depends not only on the classical attributes oft he product such as its price and quality, but also on who else is buying the same product. We model these situations as games in which firms compete for...

Social media have become an increasingly important source of information about political, social and economic issues. While beneficial on many levels, the decentralized nature of these media may expose societies to novel risks of manipulation by third parties. To evaluate these risks, we study a...

This paper studies the competition between firms for influencers in a network. Firms spend effort to convince influencers to recommend their products. The analysis identifies the offensive and defensive roles of spending on influencers. The value of an influencer only depends on the in-degree...