The aggregated excess demand function and other aggregation procedures

Summary Two theorems are given; the first extends the Sonnenschein-Mantel-Debreu theorem characterizing aggregate demand functions from the set ofn2 commodities to all of the 2 ⁿ –(n+1) subsets of two or more commodities. The second theorem concerns spatial voting models for k2 candidates over a space of n2 issues. The theorem characterizes the sincere elecion rankings of thek candidates over all of the 2 ⁿ –1 subsets of one or more issues. Both theorems have the same kind of conclusion; anything can happen. By demonstrating the mathematical reasons for these conclusions and by recalling related, recent results from statistics, voting, and economics, it is argued that this anything can happen conclusion is the type one must anticipate for aggregation procedures; particularly for the processes commonly used in economic models where the procedure is responsive to changes in agents' preferences, changes in data, etc.I am pleased to acknowledge conversations with L. Hurwicz, A. Mas-Colell and C. Simon about this material. In particular, I want to thank J. Jordan for his several helpful suggestions. Also, I benefited from comments made at meetings and seminars where these results were presented; this includes a June, 1990, conference in Stockholm, Sweden. Some stylistic suggestions were made by Arvid and Padon Kalinen. This research was supported, in part, by NSF Grant IRI-8803505.     

Airline networks as joint goods: Implications for competition policy

This article derives a model of airline services as joint goods. Using this model, the article shows how the existence of higher fares in certain hub routes may imply the market has generated a solution to the problem of covering joint costs by having a larger proportion of those costs come from hub routes, rather than the existence of any general market failure. The model is then used to make recommendations for competition policy.     

Can we afford international human rights?

In a recent important book,The Ethics of International Business, Tom Donaldson argues that multinational corporations (as well as individuals and nationstates) must, at a minimum, respect international human rights. For a purported right to be such a fundamental right it must satisfy three conditions. Donaldson calls the third condition the fairness-affordability condition. The affordability part of this condition holds that moral agents must be capable of paying for the burdens and responsibilities that a proposed human right would impose. If this is impossible, then the purported right is not an international human right.I argue that Donaldson's affordability condition is subject to four objections which reveal its untenability as one of the conditions upon which identification of international human rights must rest. I offer another way of treating problems of affordability and capability when it comes to such rights that all moral agents must respect.George G. Brenkert is Professor of Philosophy at the University of Tennessee/Knoxville. He has recently completed a book,Political Freedom, to be published by Routledge. His current research focuses on issues in business ethics.     

The Division of Labor Under Homogeneity: A Critique of Mises and Rothbard

A bstract .   Even the most passionate defenders of free trade, such as Mises and Rothbard, claim that trade cannot occur under conditions of strict homogeneity of land, labor, and capital. We show that specialization, trade, and the division of labor can emerge even when resources are initially homogenous, due to "natural heterogeneity," economies of scale, and learning.     

A comparison of different trading protocols in an agent-based market

We compare price dynamics of different market protocols (batch auction, continuous double auction and dealership) in an agent-based artificial exchange. In order to distinguish the effects of market architectures alone, we use a controlled environment where allocative and informational issues are neglected and agents do not optimize or learn. Hence, we rule out the possibility that the behavior of traders drives the price dynamics. Aiming to compare price stability and execution quality in broad sense, we analyze standard deviation, excess kurtosis, tail exponent of returns, volume, perceived gain by traders and bid-ask spread. Overall, a dealership market appears to be the best candidate, generating low volume and volatility, virtually no excess kurtosis and high perceived gain.     

Information value and efficiency measurement for risk-averse firms

This paper has three goals. First, we demonstrate that standard arguments and methods from production and duality analysis can be used to provide a comprehensive and general treatment of the value of information for a risk-averse firm with expected-utility (linear-in-probabilities) preferences and a general stochastic technology. Second, we place bounds on the value of information for a risk-averse firm and relate these bounds to characteristics of the technology and the producer’s preferences. The third and final goal is to derive the implications that information differences can have for measured efficiency differences and to relate the bounds on the value of information to those measured differences.