U-commerce: Expanding the universe of marketing

This article introduces several new concepts that lay the conceptual foundation for thinking about next-generation marketing based on ubiquitous networks. U-commerce, orüber-commerce, is predicated on the characteristics of network ubiquity, universality, uniqueness, and unison. It is proposed that the keys to managing network-driven firms are the concepts of u-space and attention analysis. The implications for next-generation marketing in the u-space are explored, with a research agenda identified for scholars and managerial implications recognized for practitioners. Richard T. Watson is the J. Rex Distinguished Chair for Internet Strategy and the director of the Center for Information Systems Leadership in the Terry College of Business, University of Georgia. He has published in leading journals in several fields as well as authored books on data management and electronic commerce and given invited seminars in nearly 20 countries. He is vice president of communications of AIS and recently finished a term as a senior editor ofMIS Quarterly. He is a visiting professor at Agder University College, Norway, and a consulting editor to John Wiley & Sons. Leyland F. Pitt is a professor of marketing in the School of Marketing, Curtin University of Technology, Perth, Australia. He is also adjunct professor of marketing at Kingston Business School, United Kingdom; the University of Lulea, Sweden; and the Ecole Nationale Ponts et Chaussees in Paris. He has also taught marketing and electronic commerce on M. B. A. and executive programs at schools such as Warwick Business School, London Business School, the Graduate School of Business at Columbia University, and the Graham School of Continuing Studies at the University of Chicago. Dr. Pitt is the author of more than 100 papers in scholarly journals, and his work has appeared in publications such asCalifornia Management Review, Sloan Management Review, Journal of the Academy of Marketing Science, Information Systems Research, Journal of Advertising Research, Communications of the ACM, andMIS Quarterly (for which he also served as associate editor). Pierre Berthon is an associate professor of marketing at Bentley College. He has held academic positions at Columbia University, Henley Management College, Cardiff University, and University of Bath. His teaching and research focus on electronic commerce, market information processing, organization and strategy, and management decision making. George M. Zinkhan is the Coca-Cola Company Chair of Marketing at the University of Georgia. After receiving his doctorate at the University of Michigan, he served on the faculty at both the University of Houston and the University of Pittsburgh. His main research focus is on the areas of communication, advertising, and electronic commerce. His recent coauthored books includeElectronic Commerce: A Strategic Perspective (2000) andConsumers (2002).     

On supply-constrained equilibria

The paper gives sufficient conditions for the existence of an equilibrium with price rigidities and quantity rationing where: (i) demand is never rationed; (ii) net trades of an a priori chosen numeraire are never rationed; and (iii) supply is rationed only when relative prices are downward rigid.     

A TEST OF A GENERAL EQUILIBRIUM STOCK OPTION PRICING MODEL

An empirical version of the Cox, Ingersoll, and Ross (1985a) call option pricing model is derived, assuming execution price uncertainty in the options market. the pricing restrictions come in the form of moment conditions in the option pricing error. These can be estimated and tested using a version of the method of simulated moments (MSM). Simulation estimates, obtained by discretely approximating the risk-neutral processes of the underlying stock price and the interest rate, are substituted for analytically unknown call prices. the asymptotics and other aspects of the MSM estimator are discussed. the model is tested on transaction prices at 15-minute intervals. It substantially outperforms the Black-Scholes model. the empirical success of the Cox-Ingersoll-Ross model implies that the continuous-time interest rate implicit in synchronous transaction quotes of 90-day Treasury-bill futures contracts is an-albeit noisy-proxy for the instantaneous volatility on common stock. the process of the instantaneous volatility is found to be close to nonstationary. It is well approximated by a heteroskedastic unit-root process. With this approximation, the Cox-Ingersoll-Ross model only slightly overprices long-maturity options.     

Optimal Income Taxation and the Ability Distribution: Implications for Migration Equilibria

As recently argued by Diamond (1998), one of the key factors explaining the progressivity of an optimal non-linear income tax is the distribution of productivity among workers. Migration is one source of changes in the productivity distribution. How changes in the populations ability distribution affect optimal income tax schedules has received little attention. Changing the distribution generally affects both the objective function and the government budget constraint. We first consider the comparative statics of the fraction of highly-skilled workers with maximin and maximax welfare functions (so that only the second effect is present) and a quasi-linear utility function. We also present some results for a utilitarian social welfare function.We then study the interaction between mobility and redistributive taxation. We consider mobility by either the skilled or unskilled population under majority voting where governments take the population as fixed. If individuals choose to relocate independently, having identical ability distributions is always a stable equilibrium when the unskilled are the mobile group. However, this is not always the case when the skilled are mobile. If groups of individuals can choose where to locate, having identical ability distributions across regions is only an equilibrium when the mobile type has an overall majority.     

Outcomes of voting and planning: Condorcet,Weber and Rawls locations

The paper is concerned with the comparison of the locations of a facility resulting from voting and planning procedures. It is shown that a voting location exists and coincides with that minimizing the total distance covered by the users to go to the facility when the transportation network contains no cycles. For a general network, least upper bounds on the ratio of the social values of the voting and planning locations are given in the cases where the total or the maximal travelled distance is minimized.     

Electronic mail — French perspective

Round Table on Electronic Mail, organized by the French Institut de Recherches Economiques et Sociales sur les Télécommunications, Paris, France, 29 November 1977.     

Disability Risk Management and Postinjury Employment of Workers With Back Pain

We analyze the outcomes of occupational back pain among four large employers that use one or more of the following disability management practices: aggressive return to work, claims management, medical management, or time‐limited job accommodations. Outcomes measured at 6 and 12 months postonset include: duration of initial work absence and the probability of returning to stable employment. Employment outcomes are better in firms with more proactive return‐to‐work policies than in firms with more restrictive policies. We devise a statistical test for attrition bias and conclude that sample attrition does not significantly alter our results.