Miscommunicating Risk,Uncertainty, and Causation: Fine Particulate Air Pollution and Mortality Risk as an Example

A recent paper in this journal (Fann et al., 2012) estimated that “about 80,000 premature mortalities would be avoided by lowering PM_2.5 levels to 5 μg/m³ nationwide” and that 2005 levels of PM_2.5 cause about 130,000 premature mortalities per year among people over age 29, with a 95% confidence interval of 51,000 to 200,000 premature mortalities per year.⁽¹⁾ These conclusions depend entirely on misinterpreting statistical coefficients describing the association between PM_2.5 and mortality rates in selected studies and models as if they were known to be valid causal coefficients. But they are not, and both the expert opinions of EPA researchers and analysis of data suggest that a true value of zero for the PM_2.5 mortality causal coefficient is not excluded by available data. Presenting continuous confidence intervals that exclude the discrete possibility of zero misrepresents what is currently known (and not known) about the hypothesized causal relation between changes in PM_2.5 levels and changes in mortality rates, suggesting greater certainty about projected health benefits than is justified.     

Purchasing management and business competitiveness in the coming decade

Changing dynamics of the marketplace require that old mind-sets of the procurement function radically shift directions. Cost-based practices of the past should be replaced by a value-added focus in today's organizational supply channel. This paper, based upon in-depth discussions with a focus group of experts, documents the upcoming challenges for purchasing professionals and defines a new role for purchasing managers. Additionally, key questions are suggested as an impetus for future research.     

Action Bias and Environmental Decisions

Individuals have a penchant for action, often for good reasons. But action bias arises if that penchant is carried over to areas where those reasons do not apply, hence is nonrational. Action bias is explored theoretically, and then empirically, using data from surveys of hypothetical environmental decisions. Quite apart from agency considerations, individuals like to affect outcomes when gains are reaped. Given the ability to help one of two sites, we find that decision makers choose to foster improvement rather than prevent deterioration, despite framing that makes it arbitrary which site is improved, which preserved. Strong action bias—individuals choosing to reap gains even though they must impose losses—is also observed. These concepts are related to loss aversion, status quo bias, omission bias for losses, and bright-line behavior.     

The role of self-assessment in the regulation and inspection of group day care

This paper considers the role of self-assessment in maintaining and improving standards of day care. A pilot study designed to investigate and develop the potential contribution of self-assessment procedures in the regulation of day nurseries is described. Self-assessment materials designed for day care providers to use in assessing the quality of their care were adapted for inspection purposes. Inspection staff in four local authorities used the materials in the inspection of ten day nurseries. Results suggest that self-assessment incorporated with inspection and development work offers a means by which providers and inspectors can work together to improve standards. Copyright © 1999 John Wiley & Sons, Ltd.     

DISTRIBUTIONAL CHARACTERIZATIONS THROUGH SCALING RELATIONS

Investigated here are aspects of the relation between the laws of X and Y where X is represented as a randomly scaled version of Y. In the case that the scaling has a beta law, the law of Y is expressed in terms of the law of X. Common continuous distributions are characterized using this beta scaling law, and choosing the distribution function of Y as a weighted version of the distribution function of X, where the weight is a power function. It is shown, without any restriction on the law of the scaling, but using a one‐parameter family of weights which includes the power weights, that characterizations can be expressed in terms of known results for the power weights. Characterizations in the case where the distribution function of Y is a positive power of the distribution function of X are examined in two special cases. Finally, conditions are given for existence of inverses of the length‐bias and stationary‐excess operators.     

Why Risk Is Not Variance: An Expository Note

Variance (or standard deviation) of return is widely used as a measure of risk in financial investment risk analysis applications, where mean‐variance analysis is applied to calculate efficient frontiers and undominated portfolios. Why, then, do health, safety, and environmental (HS&E) and reliability engineering risk analysts insist on defining risk more flexibly, as being determined by probabilities and consequences, rather than simply by variances? This note suggests an answer by providing a simple proof that mean‐variance decision making violates the principle that a rational decisionmaker should prefer higher to lower probabilities of receiving a fixed gain, all else being equal. Indeed, simply hypothesizing a continuous increasing indifference curve for mean‐variance combinations at the origin is enough to imply that a decisionmaker must find unacceptable some prospects that offer a positive probability of gain and zero probability of loss. Unlike some previous analyses of limitations of variance as a risk metric, this expository note uses only simple mathematics and does not require the additional framework of von Neumann Morgenstern utility theory.     

Village on the Border, anthropology at the crossroads: the significance of a classic British ethnography

Village on the Border was the seminal anthropological study of a mainland British rural community. It was written and published during a period of unsurpassed scholarship and creativity in British social science. To explain the impact it had on social anthropology, British studies and public discourse at the time, I look at the influences on Ronnie Frankenberg and his work of the then state of social anthropology; of the particular academic environment in which he was trained and worked; and of his personal background and political convictions. This analysis shows that although the book clearly bears particular historical and intellectual influences, it was explicitly set within comparative ethnographic frameworks, and in due course greatly influenced work elsewhere. Both methodologically and substantively, it should be seen as a significant contribution to the comparative study of local‐level politics, gender relations and the role of the ‘stranger’, as well as the authentic origin of modern anthropological studies of rural Britain.