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...

An exchange economy in which agents have convex incomplete preferences defined by families of concave utility functions is considered. Sufficient conditions for the set of efficient allocations and equilibria to coincide with the set of efficient allocations and equilibria that result when each...

We study a dynamic and infinite-dimensional model with incomplete multiple prior preferences. In interior efficient allocations, agents share a common risk-adjusted prior and subjective interest rate. Interior efficient allocations and equilibria coincide with those of economies with subjective...

We study a dynamic and infinite{dimensional model with incomplete multiple prior preferences. In interior efficient allocations, agents share a common risk{adjusted prior and subjective interest rate. Interior efficient allocations and equilibria coincide with those of economies with subjective...

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...

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...

The overlapping expectations and the collective absence of arbitrage conditions introduced in the economic literature to insure existence of Pareto optima and equilibria with short-selling when investors have a single belief about future returns, is reconsidered. Investors use measures of risk....

The overlapping expectations and the collective absence of arbitrage conditions introduced in the economic literature to insure existence of Pareto optima and equilibria when short-selling is allowed and investors hold a single belief about future returns, is reconsidered. Investors use measures...