A stumbling block in the modelling of competitive markets with commodity and price spaces of infinite dimensions, arises from having positive cones with an empty interior. This issue precludes the use of tools of differential analysis, ranging from the definition of a derivative, to the use of...

We develop an equilibrium model of commodity spot and futures markets in which commodity production, consumption, and speculation are endogenously determined. Speculators facilitate hedging by the commodity suppliers. The entry of new speculators thus increases the supply of the commodity and...

In a standard general equilibrium model it is assumed that there are no price restictionsand that prices adjust infinitely fast to their equilibrium values. In this paper the set ofadmissible prices is allowed to be an arbitrary convex set. For such an arbitrary set it cannotbe guaranteed that...

In this note we generalize the Negishi approach to equilibrium. We embed a standard one-period exchange economy into a two-period model, where agents' first-period utility functions can be any strictly increasing and concave functions satisfying the lower Inada condition, and prove the existence...

An Equivalence Theorem between geometric structures and utility functions allows new methods for understanding preferences. Our classification of valuations into "Demand Types" incorporates existing definitions (substitutes, complements, "strong substitutes", etc.) and permits new ones. Our...

We derive sufficient conditions for the existence of multiple equilibria in two-good, two-agent pure exchange economies with heterogeneous but symmetric preferences with identical Bernoulli utilities. When preferences are non-homothetic (e.g., quadratic, quasi-linear, or HARA), multiple...

In this paper, I study the existence and uniqueness of recursive equilibria in economies with aggregate and idiosyncratic risk. Rather than relying on compactness to establish existence, I exploit the monotonicity property of the equilibrium model and rely on arguments from convex analysis. This...

In an economic model of exchange of goods, the structure can be specified by utility functions. Under utility conditions identified here even more broadly than usual, except for concavity in place of quasi-concavity, every equilibrium will simultaneously be stable with respect to shifts in the...

We offer new sufficient conditions ensuring demand is downward sloping local to equilibrium. It follows that equilibrium is unique and stable in the sense that rising supply implies falling prices. In our setting, there are two goods, which we interpret as consumption in different time periods,...

This paper investigates the existence of unique equilibrium in two-good economies where agents have preferences with the same relative risk aversion and different utility weights. Aggregate demand behavior is characterized in terms of both macrolevel and micro-level information inherent in the...