Sampling from compositional and directional distributions

This paper describes a method for sampling from a non-standard distribution which is important in both population genetics and directional statistics. Current approaches rely on complicated procedures which do not work well, if at all, in high dimensions and usual parameter set-ups. We use a Gibbs sampler which seems necessary in practical situations of high dimensions.     

Game theory and global environmental policy

Economists interpret global environmental quality to be a pure public good. Each country should contribute to its provision. However, this is hard to achieve because each government is tempted to take a free ride on the other governments’ efforts. Not only has this dilemma been analysed with game theoretical methods but game theory has also been used to think about how to make amends. This paper reviews the game theoretical discussion on how international policy frameworks may be designed to improve the chances for international cooperation. It is also shown that the evaluation of alternative environmental policy instruments deviates from the standard environmental economics model if applied to the international arena. For the benefit of an interdisciplinary readership, the evolution of the debate on global environmental policy is related to the recent history of economic thought. This history is taken to be materialised in the writings of economics’ Nobel Prize laureates.     

Blood Pressure Changes among Male Navaho Migrants to an Urban Environment

Des donnees comparatives sur la pression sanguine systolique et diastolique des Navahos de sexe masculin furent recueillies avant et apres leur emigration d'un milieu rural a un centre urbain. Les deux mesures furent significativement plus elevees apres l'emigration. Quelques facteurs causaux tels que le changement d'altitude, l'ingestion de gras satures et l'age furent elimines. D'un maniere pro-visoire, on conclut que des facteurs associes a l'emigration, tels qu'un changement dans les habitudes de repos, la pollution de l'air ainsi que la separation de la parente sont a l'origine de ces changements physiologiques.
Comparative data on systolic and diastolic blood pressures were obtained on male Navahos before and after migration from a rural to an urban environment. Both measures were significantly higher after migration. Various possible causes - such as change in altitude, saturated fat intake, and age - are eliminated. It is tentatively concluded that altered rest patterns, urban pollution, and separation from kin, i.e., things specific to the act of migration, are causally implicated.     

Estimating Benchmark Exposure for Air Particulate Matter Using Latent Class Models

We performed benchmark exposure (BME) calculations for particulate matter when multiple dichotomous outcome variables are involved using latent class modeling techniques and generated separate results for both the extra risk and additional risk. The use of latent class models in this study is advantageous because it combined several outcomes into just two classes (namely, a high‐risk class and a low‐risk class) and compared these two classes to obtain the BME levels. This novel approach addresses a key problem in risk estimation—namely, the multiple comparisons problem, where separate regression models are fitted for each outcome variable and the reference exposure will rely on the results of the best‐fitting model. Because of the complex nature of the estimation process, the bootstrap approach was used to estimate the reference exposure level, thereby reducing uncertainty in the obtained values. The methodology developed in this article was applied to environmental data by identifying unmeasured class membership (e.g., morbidity vs. no morbidity class) among infants in utero using observed characteristics that included low birth weight, preterm birth, and small for gestational age.     

Public Policy and Diffusion of Innovation

Marketers have traditionally studied diffusionof innovation with a primary focus on theindividual consumer as a unit of analysis, themajor types of findings being characteristicsof adopter categories and opinion leadership. We propose that this perspective is notadequate from a macromarketing perspective, inwhich the goals are to set public policy forsocietal good or to create an environment whichenables the diffusion of an innovation in a waythat no single marketer could do alone. Insetting public policy which can enable (orinhibit) diffusion of innovation for societalgood, a system composed of a mass socialinfrastructure, a competitive infrastructure,and a technical infrastructure should beconsidered.     

Curricula and State of the Profession

Most of us have encountered problems in developing an effective quantitative analysis program for our business schools in the United States. We have often found managers very reluctant to adopt QA techniques; on the other hand, students, although not reluctant, lacked the necessary mathematical background. During the academic year 1970–71, the authors assisted in the development of a QA department in the business school of a developing nation which offers both resident coursework for graduate students and executives seminars for businessmen. Both the students and the executives had the necessary mathematical background for rapid understanding of QA techniques. The executives appeared eager to use QA in their business operations and the students were highly motivated toward the application of QA to business problems. Our purpose in this article is not to convince all the QA professors to teach in underdeveloped nations, but to furnish information which is likely to be useful to those who attempt to establish similar QA programs in other developing countries.     

Chemical and biological agent incident response and decision process for civilian and public sector facilities.

In the event of a terrorist attack or catastrophic release involving potential chemical and/or biological warfare agents, decisionmakers will need to make timely and informed choices about whether, or how, to respond. The objective of this article is to provide a decision framework to specify initial and follow-up actions, including possible decontamination, and to address long-term health and environmental issues. This decision framework consists of four phases, beginning with the identification of an incident and ending with verification that cleanup and remediation criteria have been met. The flowchart takes into account both differences and similarities among potential agents or toxins at key points in the decision-making process. Risk evaluation and communication of information to the public must be done throughout the process to ensure a successful effort.     

Social Mobility and Participation: The Dissociative and Socialization Hypotheses*

Information on participation with kin, with friends, and in voluntary associations was used to test two competing hypothescs of the effects of social mobility on social relations. The dissociative hypothesis maintains that mobility leads to social isolation, while the socialization hypothesis predicts an adptive outcome to mobility. The relationship is more complex than either position would suggest. Social mobility is associated with isolation from kin and friends, but only for the upwardly mobile. The findings obtained with voluntary associations support the socialization hypothesis in that the level of membership of the socially mobile is intermediate between the two stable groups. Social mobility has maladaptive consequences for more intimate and personal social relations, but it is integrative as far as participation in voluntary associations is concerned.