Sustainability when capital management has stochastic consequences

Sustainability is usually defined as a requirement of each generation to manage its stocks of man-made and natural capital such that the utility that it ensures itself can be shared by all future generations. Here we extend this definition to the case where capital management does not have deterministic consequences. A characterization is offered where the sustainability of one generation's behavior can be determined by comparing its utility with the utility of the succeeding generation, provided that the latter behaves in a sustainable manner. The properties of the definition are investigated and illustrated. Received: 26 April 1994/Accepted: 15 April 2002     

Aid, Relief, and Containment: The First Asylum Country and Beyond

A fundamental problem that confronts the European Union today is how it can maintain its commitment to the institution of asylum while checking irregular migration and the abuse of its asylum system. In order to explore a response to this dilemma the paper addresses the following questions: what role can relief and aid policies play in influencing migration patterns? What should be the appropriate approach to the granting of relief and aid to developing countries of first asylum? Should it be viewed as a part of the larger problem of development or be treated as a distinct issue? What kind of a relief/aid model will help refugees return to post–conflict societies and stop the conflict from reproducing itself? The paper examines two different approaches to address these questions: the alliance–containment approach and the distributive–developmental approach. It also looks at some empirical evidence, which reveals that at present it is a conservative alliance–containment approach that informs EU relief and aid practices. This approach, however, does not help achieve the stated objective of checking abuse of asylum and migration procedures while sustaining a commitment to a liberal asylum regime. The paper goes on to identify the gaps in EU policy and the lessons that can be drawn. It concludes by looking at different policy alternatives and suggesting the adoption of a reformist distributive–developmental model. The implementation of this model holds out the hope of reverting to a more liberal asylum regime while controlling irregular migration and “bogus” asylum seekers, for the reformist distributive developmental model takes a more long–term view of migration trends and also seeks to address the growing North–South divide.     

A Comparison of Partially Adaptive and Reweighted Least Squares Estimation

The small sample performance of least median of squares, reweighted least squares, least squares, least absolute deviations, and three partially adaptive estimators are compared using Monte Carlo simulations. Two data problems are addressed in the paper: (1) data generated from non-normal error distributions and (2) contaminated data. Breakdown plots are used to investigate the sensitivity of partially adaptive estimators to data contamination relative to RLS. One partially adaptive estimator performs especially well when the errors are skewed, while another partially adaptive estimator and RLS perform particularly well when the errors are extremely leptokur-totic. In comparison with RLS, partially adaptive estimators are only moderately effective in resisting data contamination; however, they outperform least squares and least absolute deviation estimators.     

Exploring multivariate data graphically:a brief review with examples

Many methods for obtaining graphical representations of multivariate data have been suggested over the last decade, but it is only relatively recently that software has become available which makes use of these procedures routine. In this paper, a number of examples are used to illustrate the application of graphical methods for the exploration of multivariate data. The diagrams produced may prove useful in consultations with clients and in examining the results from more formal methods.     

Sources of drug information among adolescent students

A sample of 1023 eighth and tenth grade students in small to medium-sized central Texas school districts was assessed to determine the amount of information they receive from ten sources about six categories of drugs. The amount of information males reported receiving about each drug category was significantly greater than what females reported, and the amount of information that eighth graders reported receiving about each drug category was significantly greater than what tenth graders reported. Television was the primary source of drug information for all categories of drugs except inhalants, for which friends and television were equally important sources. Parents and printed media (magazines or newspapers) were of secondary importance, followed by friends and teachers. Adolescents were less likely to receive drug-related information from experience, siblings, church, doctors, and police. The reliance on the mass media for drug information in smaller school districts is a pattern which has been previously observed in larger urban districts. This consistency suggests that mass media approaches to drug education are likely to be as effective in rural areas and smaller towns as they are among urban adolescents. Implications for television programming are discussed.     

Book Review: Beyond Earth Day: Fulfilling the Promise. Gaylord Nelson with Susan Campbell and Paul Wozniak. Madison,WI: The University of Wisconsin Press, 2002: 160 pp.

Population and Environment -     

Bayesian analysis of directed graphs data with applications to social networks

Summary.  A fully Bayesian analysis of directed graphs, with particular emphasis on applica- tions in social networks, is explored. The model is capable of incorporating the effects of covariates, within and between block ties and multiple responses. Inference is straightforward by using software that is based on Markov chain Monte Carlo methods. Examples are provided which highlight the variety of data sets that can be entertained and the ease with which they can be analysed.     

D-efficient window experimental designs

In the paper we present a new method of calculating sampling intervals, so-called windows, allowing an experimenter some flexibility in timing the sample collection, while a minimum required design efficiency for parameter estimation is assured. The method is based on the Equivalence Theorem for D-optimality what makes the length of each window related to the parameter sensitivities. An example of calculating the windows in a pharmacokinetic study is presented. Some other methods of calculating efficient sampling windows are briefly discussed.     

Adaptive Management: A Paradigm for Remediation of Public Facilities Following a Terrorist Attack

Terrorist actions are aimed at maximizing harm (health, psychological, economical, and political) through the combined physical impacts of the act and fear. Immediate and effective response to a terrorist act is critical to limit human and environmental harm, effectively restore facility function, and maintain public confidence. Though there have been terrorist attacks in public facilities that we have learned from, overall our experiences in restoration of public facilities following a terrorist attack are limited. Restoration of public facilities following a release of a hazardous material is inherently far more complex than in industrial settings and has many unique technical, economic, social, and political challenges. For example, there may be a great need to quickly restore the facility to full operation and allow public access even though it was not designed for easy or rapid restoration, and critical information is needed for quantitative risk assessment and effective restoration must be anticipated to be incomplete and uncertain. Whereas present planning documents have substantial linearity in their organization, the “adaptive management” paradigm provides a constructive parallel paradigm for restoration of public facilities that anticipates and plans for uncertainty, inefficiencies, and stakeholder participation. Adaptive management grew out of the need to manage and restore natural resources in highly complex and changing environments with limited knowledge about causal relationships and responses to restoration actions. Similarities between natural resource management and restoration of a public facility after a terrorist attack suggest that integration of adaptive management principles explicitly into restoration processes will result in substantially enhanced and flexible responses necessary to meet the uncertainties of potential terrorist attacks.