A demonstration of the existence of equilibrium prices for a general Walrasian model of competitive behavior necessarily makes use of some variant of Brouwer's fixed point theorem as an essential step. The strategy for calculating equilibrium prices is to render that step constructive by a...

This chapter reviews several concepts of equilibrium that have appeared in the recent literature on markets and uncertainty and focuses on various theories of equilibrium under uncertainty in a sequence of markets, in the absence of complete forward markets for contingent delivery. A stationary...

Traditional general equilibrium theory has, for a long time, studied an economic model that is essentially static, where the agent's expectations are self-fulfilling and the equilibrium is achieved solely by the price system. The chapter presents the conceptual framework underlying temporary...

The core of an economy consists of those states of the economy that no group of agents can improve upon. A group of agents can improve upon a state of the economy if the group, by using the means available to it, can make each member of that group better off, regardless of the actions of the...

The chapter is concerned with endogenous processes operating in an economy that brings equilibrium; the most famous and most discussed is the law of demand and supply. If, at prevailing market signals, there is a positive excess demand in a market price, it will rise; if there is a negative...

This chapter discusses that the mathematical model of a competitive economy conceived as an attempt to explain the state of equilibrium reached by a large number of small agents interacting through markets. Four distinct, but closely related, approaches to the existence problem are recognized....

Market demand and market excess demand functions are defined by summing the preference-maximizing actions of consumers. These functions are central to most treatments of value theory. It discusses that the demand theory of the individual consumer has been well developed. Just as consumer demand...

This chapter describes investment theory as the study of the individual behavior of households and economic organizations in the allocation of their resources to the available investment opportunities. For the purposes of investment theory, economic organizations are characterized as being...