Abstract:
This paper considers a general equilibrium model in which the=20 distinction between un-certainty and risk is formalized by assuming agents= =20 have incomplete preferences over state-contingent consumption bundles, as=20 in Bewley (1986). Without completeness, individual decision making depends= =20 on a set of probability distributions over the state space. A bundle is=20 preferred to another if and only if it has larger expected utility for all= =20 probabilities in this set. When preferences are complete this set is a=20 singleton, and the model reduces to standard expected utility. In this=20 setting, we characterize Pareto optima and equilibria, and show that the=20 presence of uncertainty generates robust indeterminacies in equilibrium=20 prices and allocations for any speci=AFcation of initial endowments. We=20 derive comparative statics results linking the degree of uncertainty with=20 changes in equilibria. Despite the presence of robust indeterminacies, we=20 show that equilibrium prices and allocations vary continuously with=20 underlying fundamentals. Equilibria in a standard risk economy are thus=20 robust to adding small degrees of uncertainty. Finally, we give conditions= =20 under which some assets are not traded due to uncertainty aversion.
JEL-codes:D0D5D8 (search for similar items in EconPapers) New Economics Papers: this item is included in nep-fmk and nep-mfd Date: 2002-01-04 Note: 52 pages, Acrobat .pdf