We consider a world in which individuals have private endowments and trade in markets while their utility is negatively affected by the consumption of their neighbors. Our interest is in understanding how the social structure of comparisons, taken together with the familiar fundamentals of the...

Favoritism is the act of offering jobs, contracts and resources to members of one's social group in preference to outsiders. Favoritism is widely practiced and this motivates an exploration of its origins and economic consequences. Our main finding is that individuals have an interest to trade...

Networks pervade social and economic life, and they play a prominent role in explaining a huge variety of social and economic phenomena. Standard economic theory did not give much credit to the role of networks until the early 1990s, but since then the study of the theory of networks has...

We examine the incentives of regions in a country to unite or to separate. We find that smaller regions have greater incentives to unite, relative to larger regions. We show, however, that on the whole, majority voting on separation and union generates excessive incentives to separate. This...

This paper examines the small world hypothesis. The first part of the paper presents empirical evidence on the evolution of a particular world: the world of journal publishing economists during the period 1970-2000. We find that in the 1970's the world of economics was a collection of islands....

We develop a model of strategic networks that captures two distinctive features of interfirm collaboration: bilateral agreements and nonexclusive relationships. Our analysis highlights the relationship between market competition, firms' incentives to invest in R&D, and the architecture of...

The authors study learning in organizations comprised of short-lived agents with heterogeneous beliefs. It is shown that the sequence of actions converges in probability to the set of ex-post optimal actions. Under some identifiability conditions, beliefs also converge in probability to point...