We study the incentive to cooperate in a nation comprised of citizens and immigrants. The level of cooperation is governed by a steady state under population dynamics, along with the behavior of individual citizens and immigrants. We provide an equilibrium characterization, exhibiting a uniquely determined positive level of cooperation in society. We then use this framework to study the impact ...

The paper proposes a model to study the conditions under which complex networks emerge (or not) when agents are involved in a dynamic coordination setup. In contrast with existing literature, however, our main focus is not on the entailed issue of equilibrium selection. Instead, our aim is to shed light on how agents’e¤orts to coordinate a¤ect the process of network formation in a large and com...

This paper rationalizes …rm’s motivation to build directed links with each other and formalizes the dynamic formation process that generates the observed network structure in the citation network. Random meeting of customers and …rms in the di¤erentiated goods market are unlikely to result in perfect match between demand and supply, but the …rm can earn commission fee by redirecting the custome...

Observational learning is typically examined when agents have precise information about their position in the sequence of play. We present a model in which agents are uncertain about their positions. Agents are allowed to have arbitrary ex-ante beliefs about their positions: they may observe their position perfectly, imperfectly, or not at all. Agents sample the decisions of past individuals an...

In this paper, we describe a series of laboratory experiments that implement specific examples of a more general network structure and we examine equilibrium selection. Specifically, actions are either strategic substitutes or strategic complements, and participants have either complete or incomplete information about the structure of a random network. Since economic environments typically have...

We create a dynamic theory of endogenous risk sharing groups, with good internal information, and their coexistence with relative performance, individualistic regimes, which are informationally more opaque. Inequality and organizational form are determined simultaneously. Numerical techniques and succinct re-formulations of mechanism design problems with suitable choice of promised utilities al...

Is it possible, simply by asking a few members of a community, to identify individuals who are best placed to diffuse information? A model of diffusion shows how members of a community can, just by tracking gossip about others, identify those who are most central in a network according to “diffusion centrality” – a network centrality measure that predicts the diffusion of a piece of information...

This paper studies bilateral insurance schemes across networks of individuals. While transfers are based on social norms, each individual must have the incentive to abide by those norms, and so we investigate the structure of self-enforcing insurance networks. Network links play two distinct and possibly conflictual roles. First, they act as conduits for transfers. Second, they act as conduits ...

The “friendship paradox” (Feld (1991)) refers to the fact that, on average, people have strictly fewer friends than their friends have. I show that this over-sampling of the most popular people amplifies behaviors that involve complementarities. People with more friends experience greater complementarities and hence take more extreme actions. Given the friendship paradox, people then perceive m...

The paper concerns a dynamic model of influence in which agents make a yes-no decision. Each agent has an initial opinion which he may change during different phases of interaction, due to mutual influence among agents. We investigate a model of influence based on aggregation functions. Each agent modifies his opinion independently of the others, by aggregating the current opinion of all agents...