Markets are incomplete when the assets available to the agents do not span the space of future contingencies. Efficiency is then assessed by the weak criterion of "constrained efficiency" (efficiency relative to the set of allocations compatible with the asset structure). That criterion requires...

In this paper the existence of unemployment is partly explained as being the result of coordination failures. This is achieved by considering a standard general equilibrium model and splitting the set of commodities in two groups. The first group contains commodities like gold. The prices of...