Why people participate in public good provision is one of the oldest questions in Economics. In the absence of enforcement mechanisms public goods would be under-provided. I develop a dynamic model of forward-looking agents in the presence of social pressure, which provides a potential...

I propose a simple model of signed network formation, where agents make friends to extract payoffs from weaker enemies. The model thereby accounts for the interplay between friendship and alliance on one hand and enmity and antagonism on the other. Nash equilibrium configurations are such that...

In many firms, production requires the division of staff into teams. If only team performance is observable, moral hazard in teams is inevitable. This variant of moral hazard can be overcome or exacerbated by the interpersonal relationships among team members. I investigate how the division of...

This article provides evidence from the Congo that social relationships with state officials can decrease one social cost of corruption, in the context of public transport. We first document that police stops can lead to long bribe negotiations. In response, some drivers and officers have built...

Demonstrating compelling causal evidence of the existence and strength of peer to peer influence has become the holy grail of modern research in online social networks. In these networks, it has been consistently demonstrated that user characteristics and behavior tend to cluster both in space...