The entropies: Some roots of ambiguity

Entropy concepts have developed in four general contexts—thermodynamics, communication theory, statistical information theory and social and life sciences. These concepts have five distinct mathematical forms. Ambiguity and complexity in utilization of the concept has been heightened by this multi-faceted heritage. Effective utilization may be strengthened by a sharper articulation of entropy through combinations of literal, mathematical and graphical modes of expression. Geography and planning as user disciplines have important responsibilities in enhancing cross-disciplinary communication of this important adisciplinary concept. Implications of these arguments for the social sciences include the need for caution in drawing social analogies from the ambiguous entropy concepts of statistical mechanics; and an indication of the potential benefits of social science models based on the unambiguous entropic constructs of statistical information theory.     

Buyer and seller perceptions of transportation purchasing variables

The study in this article involved the investigation of 15 carrier selection variables over three dimensions by three groups with high involvement in the purchasing decision—traffic managers, sales representatives, and sales managers. The primary focus of the study was the identification of significant differences in the assessment of importance of the technical abilities of a carrier, the service orientation of a carrier and the image of a carrier as perceived by sales managers and sales representatives representing the selling systems, and traffic managers representing the buying systems.     

The economics of dying: A misapplication of tools

Conclusions Unlike McKenzie and Tullock, we do not know how personsshould treat their bodily organs or what is an ideal exit. That depends upon their utility goals, which are defined in output terms specific to the decision maker. We contend that the body is an input into the utility production process, and therefore, as with any input, it must be maintained and repaired at a level consistent with the output goals for maximization of utility. Thus, from this framework, it is quite consistent for a person to die with healthy organs without any thought of belief in reincarnation or the desire to bequeath one's bodily organs to others, or religious values. Self interest is all that must prevail.Also, the fact that there are interrelationships between the organs in the system, and at points these relationships take on fixed factor characteristics such that reduced levels of operation in one organ can create disorientation or coma or damage to other organs, means that the body cannot die as M-T suggest. Zero capacity for all organs at death is a technical impossibility as well as being inconsistent with the output goals of utility maximizers.     

Frictions, Heterogeneity and Optimality in Mortgage Modeling

The purpose of this article is to provide a unified framework for incorporating frictions into a theoretical options-pricing model (OPM) for mortgages. This article presents formulation for a frictions-adjustable mortgage model that integrates borrower heterogeneity while simultaneously preserving prepayment and default financial decisions. Our model demonstrates the flexibility of the OPM by simulating separate and concurrent effects of three categories of frictions on the mortgage and mortgage components. Researchers can use our example formulation to determine the effects of specific borrower characteristics on mortgage values without destroying the options theoretic framework.     

The measurement of corporate portfolio strategy: analysis of the content validity of related diversification indexes

Measures developed for the analysis of corporate diversification have become fundamental to a broad range of strategy research. This paper examines the content validity of the two most widely used continuous measures of related diversification—the related component of the entropy index and the concentric index—and raises fundamental questions about their validity as indicators of portfolio relatedness. These questions are not driven by the use of SIC data for estimation of the indexes; they involve validity problems intrinsic to the construction of the measures. The related component of entropy and the concentric index are sensitive to features of corporate portfolio composition that may not be directly linked to portfolio relatedness. These sensitivities can create important ambiguities in strategy research. Copyright © 2002 John Wiley & Sons, Ltd.