ATSDR Science Panel on the Bioavailability of Mercury in Soils: Lessons Learned

On the basis of discussion and analysis during and following an ATSDR science panel on the bioavailability of mercury in soils, it is apparent that the default assumption of 100% relative bioavailability for mercury-contaminated soils is excessively conservative. However, current knowledge does not allow the development of default assumptions or guidelines for determining relative bioavailability of mercury in soils. Until such default assumptions or guidelines can be developed, site-specific assays of bioavailability, preferably using either animal bioassays or validated in vitro techniques, may provide the best approach for estimating soil-mercury bioavailability.     

Volatility-based Effects on Shareholder Value: Alliance Activity in the Computing Industry

We use an event-study analysis to understand how alliance activity affects firm risk. The risk measure is the implied volatility of a firm’s stock price and the events are alliance announcements to the market. We build on the previous event-studies in the alliance literature that focus on the change in shareholder value by taking the first step in delineating what part of that value arises from the changes in the firm’s risk. The analysis reveals that a number of factors within a firm’s control can be used to manipulate risk exposure in an alliance, including the similarity of the firm’s and the alliance’s core activities, the governance form of the alliance, and the function of the alliance.     

A Conceptual Model for Researching the Creation and Operation of Supply Networks1

This paper presents a conceptual model for the creation and operation of supply networks. Existing conceptual research relating to interorganizational relationships and networks is reviewed in terms of its relevance to understanding supply networks; this research is drawn from the fields of strategic management, channel management, industrial marketing and purchasing, organizational behaviour and supply‐chain management. The different perspectives each field has on networks are highlighted. Contributions made by each in assisting to understand supply networks are discussed and synthesized. Findings from an exploratory survey are used to structure the design of a conceptual model for analysing the processes involved in the creation and operation of supply networks. The authors identify nine different types of networking activities and discuss the nature of these activities in the context of supply. Four different types of contextual factors relating to supply networks are identified. The model is tested in eight in‐depth case studies and a validating survey of 58 focal firm networks. It is concluded that it provides a robust structure that enabled complex, cross‐case analysis of multi‐variable, multi‐disciplinary data from interorganization product/service supply networks, but that further testing by other researchers is required.     

Developing the Concept of Transparency for Use in Supply Relationships

Management concern surrounding the supply of goods and services from business to business, and the related attempts to understand the phenomena observed therein, appears to rest upon a broad range of incompatible perspectives, from political science (often limited to considerations of power) to the logistical (akin to manipulation of a great, benign but dynamic jigsaw puzzle). It appears that all perspectives abrade against the difficulties of exchanging information, knowledge and innovation within the relationships between buying and selling organizations and the apparent chronic systemic inefficiency that transactions often represent in this context. This article addresses these concerns, exploring the concept of transparency and the developments necessary for it to be useful in exchanging sensitive information and tacit knowledge in supply relationships. Our central concern is how the understanding of transparency and its commercial importance may change when it is expressed as a manageable element of the relationship between two organizations rather than as a general property of a broader system (e.g. a supply network, industrial sub-sector, geographical cluster) and what utility this differentiation might hold for managers. The conclusion to the article, and the implication for managers, is that transparency might indeed be created and usefully managed within supply relationships but that it would differ fundamentally in meaning from previously posited concepts, with the same name, in different contexts.     

MARKET PENETRATION AND LOCATIONAL CONFLICT IN FRANCHISE SYSTEMS*

This paper addresses the questions of market penetration and locational conflict in a franchise system of distribution. The models developed provide a means to evaluate alternative scenarios and the effects of various franchise policies. It is shown that the market penetration and location goals of the members of a franchise system coincide only under a very limited set of circumstances.     

The Value of Information in Decision‐Analytic Modeling for Malaria Vector Control in East Africa

Decision analysis tools and mathematical modeling are increasingly emphasized in malaria control programs worldwide to improve resource allocation and address ongoing challenges with sustainability. However, such tools require substantial scientific evidence, which is costly to acquire. The value of information (VOI) has been proposed as a metric for gauging the value of reduced model uncertainty. We apply this concept to an evidenced‐based Malaria Decision Analysis Support Tool (MDAST) designed for application in East Africa. In developing MDAST, substantial gaps in the scientific evidence base were identified regarding insecticide resistance in malaria vector control and the effectiveness of alternative mosquito control approaches, including larviciding. We identify four entomological parameters in the model (two for insecticide resistance and two for larviciding) that involve high levels of uncertainty and to which outputs in MDAST are sensitive. We estimate and compare a VOI for combinations of these parameters in evaluating three policy alternatives relative to a status quo policy. We find having perfect information on the uncertain parameters could improve program net benefits by up to 5–21%, with the highest VOI associated with jointly eliminating uncertainty about reproductive speed of malaria‐transmitting mosquitoes and initial efficacy of larviciding at reducing the emergence of new adult mosquitoes. Future research on parameter uncertainty in decision analysis of malaria control policy should investigate the VOI with respect to other aspects of malaria transmission (such as antimalarial resistance), the costs of reducing uncertainty in these parameters, and the extent to which imperfect information about these parameters can improve payoffs.     

Letter to the editor: Are indicators telling us the real story about progress?

Social Indicators Research - Global politics is based on an outmoded and increasingly destructive model of human progress and development. Can science change a dire situation?     

Media Disaster Reporting Effects on Public Risk Perception and Response to Escalating Tornado Warnings: A Natural Experiment

Previous research has evaluated public risk perception and response to a natural hazards in various settings; however, most of these studies were conducted either with a single scenario or after a natural disaster struck. To better understand the dynamic relationships among affect, risk perception, and behavioral intentions related to natural disasters, the current study implements a simulation scenario with escalating weather intensity, and includes a natural experiment allowing comparison of public response before and after a severe tornado event with extensive coverage by the national media. The current study also manipulated the display of warning information, and investigated whether the warning system display format influences public response. Results indicate that (1) affect, risk perception, and behavioral intention escalated as weather conditions deteriorated, (2) responses at previous stages predicted responses at subsequent stages of storm progression, and (3) negative affect predicted risk perception. Moreover, risk perception and behavioral intention were heightened after exposure to the media coverage of an actual tornado disaster. However, the display format manipulation did not influence behavioral responses. The current study provides insight regarding public perception of predisaster warnings and the influence of exposure to media coverage of an actual disaster event.     

The Practical Significance of Measurement Error in Pulmonary Function Testing Conducted in Research Settings

Conventional spirometry produces measurement error by using repeatability criteria (RC) to discard acceptable data and terminating tests early when RC are met. These practices also implicitly assume that there is no variation across maneuvers within each test. This has implications for air pollution regulations that rely on pulmonary function tests to determine adverse effects or set standards. We perform a Monte Carlo simulation of 20,902 tests of forced expiratory volume in 1 second (FEV₁), each with eight maneuvers, for an individual with empirically obtained, plausibly normal pulmonary function. Default coefficients of variation for inter‐ and intratest variability (3% and 6%, respectively) are employed. Measurement error is defined as the difference between results from the conventional protocol and an unconstrained, eight‐maneuver alternative. In the default model, average measurement error is shown to be ～5%. The minimum difference necessary for statistical significance at p < 0.05 for a before/after comparison is shown to be 16%. Meanwhile, the U.S. Environmental Protection Agency has deemed single‐digit percentage decrements in FEV₁ sufficient to justify more stringent national ambient air quality standards. Sensitivity analysis reveals that results are insensitive to intertest variability but highly sensitive to intratest variability. Halving the latter to 3% reduces measurement error by 55%. Increasing it to 9% or 12% increases measurement error by 65% or 125%, respectively. Within‐day FEV₁ differences ≤5% among normal subjects are believed to be clinically insignificant. Therefore, many differences reported as statistically significant are likely to be artifactual. Reliable data are needed to estimate intratest variability for the general population, subpopulations of interest, and research samples. Sensitive subpopulations (e.g., chronic obstructive pulmonary disease or COPD patients, asthmatics, children) are likely to have higher intratest variability, making it more difficult to derive valid statistical inferences about differences observed after treatment or exposure.     

Bibliometric analysis of production planning and control (1990–2016)

Production Planning and Control (PPC) has been one of the primary publishing outlets for operations management research for nearly three decades. This paper presents bibliometric analysis of the journal from its inception through 2016. PPC was analysed from six different perspectives to provide reliable and in-depth information about the journal’s performance and development. The analysis considered the development of the journal itself, the countries of contributing authors, authors’ academic and practitioner organisation affiliations, the top publishing and most cited authors, the most cited articles, and finally the topics of published papers through analysis of titles, keywords and abstracts. It was found that the journal is considered an outlet for both practice and academic research, reflecting changes over time in the landscape of operations management.