For strictly quasi concave differentiable utility functions, demand is shown to be differentiable almost everywhere if marginal utilities are pointwise Lipschitzian. For concave utility functions, demand is differentiable almost everywhere in the case of differentiable additively separable...

We discuss the issue, raised by Mas-Colell (1991) whether the local uniqueness (relative to the L∞ topology) may be a generic property of equilibria in incomplete markets economies with a continuum of states.

We show that when bankruptcy, subject to penalties, is allowed, it is possible to prove the existence of equilibrium in a model with a continuum of states without imposing any assumptions on ex-post endowments.