[A set of independent axioms are exhibited which characterize the price mechanism. The Debreu-Scarf limit theorem on the core of an economy and a category theory viewpoint are employed in the analysis.]

[The purpose of this paper is to investigate the structure of the class of market excess demand functions which can be generated by aggregating individual utility maximizing behavior. Among the results are: (i) in a region of the relative price domain an arbitrary polynomial function can be generated as an excess demand function for a particular commodity, and (ii) for any p in the relative price domain, a given configuration of excess demands and rates of change in excess demand can be generated at p if and only if it is consistent with Walras' Law.]

Recently, attention has been given to a model of two-person bargaining in which the parties alternate making of fers and there is uncertainty about the valuation of one party. The p urpose of the analysis has been to identify delay to agreement with a screening process, where agents with relatively lower valuations dis tinguish themselves by waiting longer to settle. The authors point ou t a fundamental difficulty with this program by demonstrating that th e assumptions used in the literature allow for delay only in so far a s the time between offers is significant.

We study a standard n-commodity model in which equilibrium positions are characterized by specified inequalities between society's marginal rates of transformation in production and a single consumer's marginal rates of substitution in consumption; these inequalities are exemplified by, but not limited to, excise and subsidies. We explore circumstances under which certain increases in these taxes and subsidies can be said to decrease welfare. In order to do so, we look for conditions under which the equilibrium consumption vector is well defined by a specification of the and subsidies, and find that the conditions required are stringent. Among our conclusions is the proposition that the validity of consumers' surplus measures for analyzing such problems may depend on assumptions that are more strict than their users have realized.

In this paper we provide a statement of the relationship between the weak axiom of revealed preference (WA) and the negative semidefiniteness of the matrix of substitution terms (NSD). As a corollary we determine the relation between WA and the strong axiom of revealed preference (SA). The latter is equivalent to NSD and the symmetry of the matrix of substitution terms. The former, WA, implies NSD but is not implied by NSD. Also, WA is implied by the condition that the matrix of substitution terms is negative definite (ND), but it does not imply ND. Application of these results yield an infinity of demand functions which satisfy WA but not SA.

An allocation for an exchange economy with smooth preferences is shown to be Walrasian if there is a set of net trades that is closed under addition, contains the negations of net trades that would improve any agent's final bundle, and is such that each agent's final bundle is weakly preferred to the sum of the initial endowment and any allowed net trade. These conditions characterize the sets of net trades available in equilibria of market games in which randomly paired agents bargain repeatedly and imply that steady state equilibria are Walrasian.

[Available theorems establishing the existence of general equilibrium in models incorporating imperfectly competitive firms rely on the assumption that reaction curves are continuous functions (or convex-valued, upper hemi-continuous correspondences). However, this property has not been derived from conditions on the fundamental data of tastes, technology, and maximizing behavior. We show here that continuity may fail even in extremely simple cases, with the result that equilibrium price and/or quantity choices fail to exist. The non-pathological nature of the examples we present suggests the need for a fundamental re-examination of the way our partial and general equilibrium models of monopolistic competition fit together.]

Consider a Bayesian collective decision problem in which the preferences of agents are private information. We provide a general demonstration that the utility costs associated with incentive constraints become negligible when the decision problem is linked with a large number of independent copies of itself. This is established by defining a mechanism in which agents must budget their representations of preferences so that the frequency of preferences across problems mirrors the underlying distribution of preferences, and then arguing that agents' incentives are to satisfy their budget by being as truthful as possible. We also show that all equilibria of the linking mechanisms converge to the target utility levels. The mechanisms do not require transferable utility or interpersonal comparisons of utility, and are immune to manipulations by coalitions.