Children's hospitals: specialty hospitals that treat children specially

Any reader who has children will agree that they make special patients, whether at home or in the hospital. These patients have unique requirements for love and compassionate care, and children's hospitals deliver on their promises. The well-run children's hospitals researched for this article have converted their material management operational challenges to opportunities. They have built thoughtful material management strategic plans, reorganized their support services to provide customer service to end users, and they have centered their materiel management efforts around service and quality improvement.     

On estimating the reliability after sequentially estimating the mean: The exponential case

Sequential estimation problems for the mean parameter of an exponential distribution has received much attention over the years. Purely sequential and accelerated sequential estimators and their asymptotic second-order characteristics have been laid out in the existing literature, both for minimum risk point as well as bounded length confidence interval estimation of the mean parameter. Having obtained a data set from such sequentially designed experiments, the paper investigates estimation problems for the associatedreliability function. Second-order approximations are provided for the bias and mean squared error of the proposed estimator of the reliability function, first under a general setup. An ad hoc bias-corrected version is also introduced. Then, the proposed estimator is investigated further under some specific sequential sampling strategies, already available in the literature. In the end, simulation results are presented for comparing the proposed estimators of the reliability function for moderate sample sizes and various sequential sampling strategies.     

The generality/specificity issue in consumer innovativeness research

The purpose of the present study was to explore the role of personality in shaping consumer innovativeness by testing a model of the hierarchical relationships between a global (broad or abstract) personality trait, its domain-specific manifestation in a consumer context, and overt consumer behavior. A survey of 465 adult consumers measured global innovativeness, domain-specific innovativeness for two product categories (clothing and electronics) and self-reported purchase of new clothing and electronic items. Three hypotheses were tested. First, global innovativeness is more highly correlated with domain-specific innovativeness than it is with the purchase of new items. Second, domain-specific innovativeness is more highly correlated with the purchase of new items than is global innovativeness. Finally, the association between global innovativeness and new product purchase is mediated by domain-specific innovativeness. All three hypotheses were supported for both product categories.     

Effective regulation versus tacit collusion in the long-distance market: an empirical analysis

Regulatory decisions often must be made in an atmosphere of uncertainty, and arguments presented by the affected parties frequently add to, rather than resolve, that uncertainty. Here, we examine several of the deregulatory decisions affecting the long-distance market that were rendered by the FCC over the two-decade period following the divestiture of AT&T. Our purpose is to provide empirical evidence relevant to some of the arguments regarding market conditions that were presented during that period. Findings suggest that some of the more prominent allegations are not supported by the data.      

Anonymous monotonic social welfare functions

This paper presents two results about preference domain conditions that deepen our understanding of anonymous and monotonic Arrovian social welfare functions (ASWFs). We characterize the class of anonymous and monotonic ASWFs on domains without Condorcet triples. This extends and generalizes an earlier characterization (as Generalized Majority Rules) by Moulin (Axioms of Cooperative Decision Making, Cambridge University Press, New York, 1988) for single-peaked domains. We also describe a domain where anonymous and monotonic ASWFs exist only when there are an odd number of agents. This is a counter-example to a claim by Muller (Int. Econ. Rev. 23 (1982) 609), who asserted that the existence of 3-person anonymous and monotonic ASWFs guaranteed the existence of n-person anonymous and monotonic ASWFs for any n>3. Both results build upon the integer programming approach to the study of ASWFs introduced in Sethuraman et al. (Math. Oper. Res. 28 (2003) 309).     

Modularity and productivity: Assessing the impact of digital technology in the U.S. telecommunication industry

This article investigates the impact of digital technology diffusion on the productivity of firms making up the local operating sector of the U.S. telecommunications industry for the years 1991 to 1993. Diffusion of digital technology is measured as the extent of line digitalization that has taken place, with digitalization expected to enable firms to reap significant operating efficiencies. While the diffusion of this particular technology in the local operating company sector has been relatively low, it is found that, after controlling for the effects of a number of other covariates also likely to affect firm-level performance, the spread of digital technology within the U.S. local telephone network plays a significant and positive role in impacting productive efficiency of the firms making up the network. The investments that have been made in energizing the U.S. information superhighway, via the digitalization of telephone lines, are justified in productive efficiency terms. The article contributes to empirical literature in the technical change area which assesses the firm-level productive efficiency consequences of technology diffusion.     

Diffusion of innovations in globally stable Walrasian equilibrium

When all products in the economy are weak gross substitutes, preferences are homothetic, and firms face menu costs then all prices in an industry move together at the same rate. In the closed-loop Nash noncooperative equilibrium, all firms invest in productivity and reduce real prices. As a result, in the case of quadratic menu costs, the outputs of industries and the economy go up along S-shaped time paths characteristic of diffusion of innovations.     

Social learning with private and common values

Summary. We consider an environment where individuals sequentially choose among several actions. The payoff to an individual depends on her action choice, the state of the world, and an idiosyncratic, privately observed preference shock. Under weak conditions, as the number of individuals increases, the sequence of choices always reveals the state of the world. This contrasts with the familiar result for pure common-value environments where the state is never learned, resulting in herds or informational cascades. The medium run dynamics to convergence can be very complex and non-monotone: posterior beliefs may be concentrated on a wrong state for a long time, shifting suddenly to the correct state.Received: 6 January 2005, Revised: 5 May 2005, JEL Classification Numbers: C72, D82.Jacob K. Goeree: Correspondence toFinancial support from the National Science Foundation NSF (SBR-0098400 and SES-0079301) and the Alfred P. Sloan Foundation is gratefully acknowledged. We thank Richard McKelvey posthumously for insights and conjectures about information aggregation that helped shape our thinking about the problem. We also acknowledge helpful comments from Kim Border, Tilman Börgers, Bogachen Celen, Luis Corchon, Matthew Jackson and seminar participants at University College London, the University of Arizona, Universitat Autonoma de Barcelona, the California Institute of Technology, the 2003 annual meeting of ESA in Pittsburgh, the 2003 Malaga Workshop on Social Choice and Welfare Economics, the 2003 SAET meetings in Rhodos, and the 2003 ESSET meetings in Gerzensee.