An imperfectly competitive economy is very prone to market uncertainty, including uncertainty about the liquidity (or "thickness") of markets. The authors show, in particular, that there exist stochastic equilibrium outcomes in nonstochastic market games if (and only if) the endowments are not...

The authors investigate the structure of competitive equilibria in an exchange economy parametrized by endowments and restrictions on market participation. For arbitrary regular endowments, if few consumers are restricted, there are no sunspot equilibria. If endowments are allowed to vary, while...