This paper considers the necessity and sufficiency of multiple certainty equilibria for sunspot effects, and shows that neither implication is valid. This claim is made for models with incomplete markets and numeraire assets. First, I prove that a multiplicity of certainty equilibria is neither...

In this paper, I examine a two-period general equilibrium model in which transaction costs are incurred whenever financial contracts are traded. These transaction costs are real and convex. The presence of these transaction costs results in a Pareto inefficient equilibrium allocation. Attempting...