We consider a general equilibrium model under imperfect competition. Firms have constantreturns, they are price taker in the input market and compete à la Cournot in theproduct market. We assume a representative consumer exists. We show that an increase inthe number of firms of a given market...

We consider a simple general equilibrium model with imperfect competition. Firms are price taker in the input market and compete à la Cournot in some or all of the product markets (their technology displays constant returns to scale). We show that an increase in the number of firms does not...

We consider decision-makers facing a risky wealth prospect. The probability distribution depends on pecuniary effort, e.g., the amount invested in a venture or prevention expenditures to protect against accidental losses. We provide necessary local conditions and sufficient global conditions for...

We provide sufficient conditions for the first-order approach in the principal-agent problem when the agent’s utility has the nonseparable form u(y−c(a)) where y is the contractual payoff and c(a) is the money cost of effort. We first consider a decision-maker facing prospects which cost...

We incorporate the concept of evidentiary standard to the analysis of the negligence rule under liability insurance and court errors. When the postaccident evidence is privately contractible and not too noisy, efficiency is achieved by both strict liability and a negligence rule with appropriate...

We analyze the efficiency properties of the negligence rule with liability insurance, when the tort-feasor's behavior is imperfectly observable both by the insurer and the court. Efficiency is shown to depend on the extent to which the evidence is informative, on the evidentiary standard for...