We study frictionless matching models in large production economies with and without market imperfections and/or incentive problems. We provide necessary and sufficient distribution-free conditions for monotone matching which depend on the relationship between what we call the segregation payoff...

This paper analyzes social group formation when agents are subject to peer effects within groups increasing human capital and instantaneous utility. When agents are heterogeneous on two dimensions, ability and social skills, and monetary payments are not feasible the model predicts segregation...

We analyze the welfare consequences of an increase in the commissions charged by the organizer of an auction. Commissions are similar to taxes imposed on buyers and sellers and the economic problem that results looks similar to the question of tax incidence in consumer economics. We argue,...