Demand Constraints on Agricultural Growth in East and Southern Africa: A General Equilibrium Analysis

This article analyses demand constraints on agricultural growth in seven countries of East and Southern Africa using an applied general equilibrium framework. It finds that both traditional and non‐traditional export crops have limited potential to raise incomes because of demand constraints (for traditional exports) or a relatively small base (for non‐traditional exports). The best prospects for agriculture‐led growth remain in the food sector, where domestic demand represents a large and growing market. Improvements in market efficiency and simultaneous growth in the livestock sectors can help spur demand further and avert falls in prices. Achieving rapid gains in farm incomes, however, also requires investment in rural infrastructure to reduce marketing costs, and demand‐ enhancing growth in the non‐agricultural sector to spur demand.     

Development and Consideration of Global Policies for Managing the Future Risks of Poliovirus Outbreaks: Insights and Lessons Learned Through Modeling

The success of the Global Polio Eradication Initiative promises to bring large benefits, including sustained improvements in quality of life (i.e., cases of paralytic disease and deaths avoided) and costs saved from cessation of vaccination. Obtaining and maintaining these benefits requires that policymakers manage the transition from the current massive use of oral poliovirus vaccine (OPV) to a world without OPV and free of the risks of potential future reintroductions of live polioviruses. This article describes the analytical journey that began in 2001 with a retrospective case study on polio risk management and led to development of dynamic integrated risk, economic, and decision analysis tools to inform global policies for managing the risks of polio. This analytical journey has provided several key insights and lessons learned that will be useful to future analysts involved in similar complex decision-making processes.     

Teachers' role in the primary prevention of child abuse dilemmas and problems

During the 1980s, many school-based primary prevention programmes were developed and adopted by schools. Much of the early enthusiasm which greeted these programmes dissipated in the light of often disappointing evaluations of the impact of the programmes on children. It is argued, however, that evaluating student outcomes should not occur before theextent of programme utilization is established. In this paper, an overview is given on the dilemmas and problems faced by teachers attempting to implement a primary prevention programme in South Australia. It is revealed that teachers selectively omit sections of the primary prevention programme as a way of resolving personal dilemmas presented by the programme. Some teachers are sensitive about teaching personal and controversial issues related to child abuse, while others deny the seriousness of child abuse in theirschool. The implications of the findings are that: (a) it cannot be assumed that primary prevention programmes are implemented by teachers in ways that are consistent with programme design; (b) teachers' personal beliefs, attitudes and feelings need to be addressed in any school-based primary prevention initiative; (c) training approaches and school support mechanisms need to focus on methods by which teachers can resolve the dilemmas raised by school-based primary prevention programmes in ways other than by radically dismembering the programme.     

Stigma Happens: Social Problems in the Siting of Nuclear Waste Facilities

The paper by Metz challenges the view that stigma associated with a nuclear waste repository might lead to significant economic losses to the host region. We have been invited to comment on the general issues raised by this paper. We find that much of the evidence presented in the paper consists of factual and conceptual errors and misrepresentations of the research literature. Based on our review of evidence documenting the social and economic impacts of perceived risk, we conclude that stigma is an important phenomenon that is symptomatic of fundamental problems with the way in which nuclear waste facilities are sited.     

A preliminary test of the validity of the LCSW examination

Social workers seeking licensure in most states must pass one of the four different written examinations developed by the American Association of State Social Work Boards (AASSWB). These examinations are claimed to be valid measures of professional social work knowledge and competence to practice. To test this claim, we administered the multiple-choice 50-item Advanced practice examination contained within the official AASSWB Advanced study guide to 42 first year MSW students. Weblanked out the actual question content, and asked the students to select the correct answers from among the four choices given. Chance would suggest that the average score should be about 25% correct (one out of four). In actualitythe students' scores averaged 37% correct, a statistically significant difference. These results challenge the content and discriminant validity of the AASSWB examination and call for further studies on the examinations' value.     

Exposure Assessment: Then, Now, and Quantum Leaps in the Future

Health risk assessments have become so widely accepted in the United States that their conclusions are a major factor in many environmental decisions. Although the risk assessment paradigm is 10 years old, the basic risk assessment process has been used by certain regulatory agencies for nearly 40 years. Each of the four components of the paradigm has undergone significant refinements, particularly during the last 5 years. A recent step in the development of the exposure assessment component can be found in the 1992 EPA Guidelines for Exposure Assessment. Rather than assuming worst-case or hypothetical maximum exposures, these guidelines are designed to lead to an accurate characterization, making use of a number of scientific advances. Many exposure parameters have become better defined, and more sensitive techniques now exist for measuring concentrations of contaminants in the environnment. Statistical procedures for characterizing variability, using Monte Carlo or similar approaches, eliminate the need to select point estimates for all individual exposure parameters. These probabilistic models can more accurately characterize the full range of exposures that may potentially be encountered by a given population at a particular site, reducing the need to select highly conservative values to account for this form of uncertainty in the exposure estimate. Lastly, our awareness of the uncertainties in the exposure assessment as well as our knowledge as to how best to characterize them will almost certainly provide evaluations that will be more credible and, therein, more useful to risk managers. If these refinements are incorporated into future exposure assessments, it is likely that our resources will be devoted to problems that, when resolved, will yield the largest improvement in public health.     

EFFICIENT USER CHARGES IN A RENT-SEEKING MODEL

This paper examines efficient user charges on governmentally provided facilities in the presence of rent seeking. We find that the efficient user charge depends upon the relative slopes of the demand curve for the use of the facility and the corresponding marginal cost curve, as well as the level of rent seeking over the revenue raised. Except for a special case, the efficient user charge is found to differ from the charge indicated by the intersection of demand and marginal cost curves. Examples show that actual user charges on government facilities are often set at inefficient levels.