This paper analyses the qualitative properties of optimal contracts when agents have multiple priors and are uncertainty averse in an infinite state space framework. The case of the epsilon-contamination of a given prior, a basic tool in robustness theory is fully developped. It is shown that if...

This paper considers a class of one dimensional calculus of variations problems with monotonicity and comonotonicity constraints arising in economic and financial models where law invariant concave criteria (or law invariant convex measures of risk) are used. Existence solutions, optimality...

This paper reconsiders the theory of existence of efficient allocations and equilibria when consumption sets are unbounded below under the assumption that agents have incomplete preferences. Our model is motivated by an example in the theory of assets with short-selling where there is risk and...

In this note, we study the problem of existence, uniqueness and determinacy of equilibrium in the two period mean-variance C.A.P.M. with a riskless asset and possibly an infinite number of assets. The existence, uniqueness and determinacy problem is brought down to a two-dimensional problem. We...

We study a dynamic and in nite{dimensional model with Knightian uncertainty modeled by incomplete multiple prior preferences. In in- terior e cient allocations, agents share a common risk{adjusted prior and use the same subjective interest rate. Interior e cient alloca- tions and equilibria...

This paper examines qualitative properties of efficient insurance contracts in the presence of background risk. In order to get results for all strictly risk-averse expected utility maximizers, the concept of “stochastic increasingness” is used. Different assumptions on the stochastic...

The theory of existence of equilibrium with short-selling is reconsidered under risk and ambiguity modelled by risk averse variational preferences. A sufficient condition for existence of efficient allocations is that the relative interiors of the risk adjusted sets of expectations overlap. This...

Efficient risk-sharing rules and equilibria between two agents with utilities in a class that contains the Rank Dependent Expected Util- ity (RDU) are fully characterized. Specific attention is given to the RDU. Call-spreads and contracts with mixed regimes are shown to be efficient....