This paper constructs a closed set Y in R' such that for all y in the boundary of Y Clarke's normal cone to Y at y is equal to R'+. If Y is the production set of a tirm, then the marginal cost pricing rule imposes no restriction. The existence of Y is shown to be equivalent to the existence of a...

Consider a firm owned by shareholders with heterogeneous beliefs and run by a manager. Shareholders can trade contingent claims in a complete asset market. The manager is given a contract so that at equilibrium she chooses the plan preferred by shareholders. We show that the contract should...

In this paper we eliminate the free disposal assumption in a general equilibrium model in which the production sector may exhibit increasing returns to scale or more general types of nonconvexities and where the firms follow general pricing rules. Under standard assumptions in this framework, we...