Local merchant guilds were ubiquitous in medieval Europe, and their development was inextricably linked with the development of towns and the rise of the merchant class. We develop a theory of the emergence of local merchant guilds as an efficient mechanism to implement collusion among merchants...

We develop an agency model of organized crime accounting for the main trade-offs involved by the introduction of an accomplice-witness program. We characterize the optimal policy and identify its main determinants in a framework where public officials can be dishonest. Our predictions are tested...

When a customer can borrow from several competing banks, multiple lending raises default risk. If creditor rights are poorly protected, this contractual externality can generate novel equilibria with strategic default and rationing, in addition to equilibria with excessive lending or...

We study a general equilibrium model where agents' preferences, productivity and labour endowments depend on their health status, and occupational choices affect individual health distributions. Efficiency typically requires agents of the same type to obtain different expected utilities if...