This paper studies the question: Why are there Firms? Motivated by observations of a variety of economies, several distinct concepts of what it means to be a firm are identified and then analyzed with mechanism design models. In the first class of models, a group of individuals is a firm if they...

This mechanism design paper studies the assignment of people to projects over time. Inability to communicate interim shocks is a force for long-term assignments, though exceptions exist for high risk aversion. In contrast, costless reporting of interim shocks makes switching powerful for...

This paper proves the Welfare Theorems and the existence of a competitive equilibrium for the club economies with private information in Prescott and Townsend (2005). The proofs cover lottery economies with a finite number of goods and without free disposal. A mapping based on Negishi (1960) is...

Using private information and club theories, this paper develops a theory of firms in general equilibrium. Firms are defined to be assignments of technologies and agents to clubs. In equilibrium, firms form endogenously and multiple types may co-exist. We formulate the general equilibrium...