[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.