Climate change

At the Copenhagen conference our leaders failed to agree on a course of firm action against climate change. We present three articles on the post-Copenhagen world. In the first of them, Richard Chandler, Jonathan Rougier and Mat Collins describe statistical work that still needs to be done.     

Integrating commercial and residential pickup and delivery networks: A case study

This paper presents a strategic analysis of the network design problem faced by pickup and delivery companies operating in metropolitan areas and serving two or more classes of customers. The focus is on a division that treats commercial and residential customers separately, a situation motivated by their respective geographic densities and the size and frequency of their demand. In constructing driver work areas, it is necessary to take into account expected demand, vehicle capacity, time on the road, and the aspect ratio of the individual territories. This leads to a capacitated clustering problem with side constraints that has been the subject of intense research over the last decade.     

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.     

Toward Probabilistic Prediction of Flash Flood Human Impacts

This article focuses on conceptual and methodological developments allowing the integration of physical and social dynamics leading to model forecasts of circumstance‐specific human losses during a flash flood. To reach this objective, a random forest classifier is applied to assess the likelihood of fatality occurrence for a given circumstance as a function of representative indicators. Here, vehicle‐related circumstance is chosen as the literature indicates that most fatalities from flash flooding fall in this category. A database of flash flood events, with and without human losses from 2001 to 2011 in the United States, is supplemented with other variables describing the storm event, the spatial distribution of the sensitive characteristics of the exposed population, and built environment at the county level. The catastrophic flash floods of May 2015 in the states of Texas and Oklahoma are used as a case study to map the dynamics of the estimated probabilistic human risk on a daily scale. The results indicate the importance of time‐ and space‐dependent human vulnerability and risk assessment for short‐fuse flood events. The need for more systematic human impact data collection is also highlighted to advance impact‐based predictive models for flash flood casualties using machine‐learning approaches in the future.     

Projecting Australia's Fertility—Postscript

An accelerated decline in family size has led to a downward revision of projected fertility. Replacement fertility could be reached in the 1980s with births numbering about 250,000 a year. The population is approaching stability at the younger ages. The potential for poverty arising from large families may be halved in ten years.     

Homosexual not Homogeneous: A Motivation-Based Typology of Gay Leisure Travelers Holidaying in Cape Town,South Africa

ABSTRACT

The gay traveler, a segment of the lesbian, gay, bisexual, and transgender (LGBT) travel market, is perceived to be a homogeneous market segment as a result of the assumption that gay men have a unique “homosexual lifestyle.” This assumption is problematic as it conceals many other important variables, and it may hinder effective destination marketing. A Web-based electronic survey was completed by 469 gay male travelers, and attribute-based benefit segmentation was carried out by applying a hierarchical cluster analysis using Ward’s procedure with Euclidean distances. The typology is based on the push and pull framework; the motivations of travelers were assessed both in terms of their socio-psychological motivations and destination attributes of Cape Town. The typology empirically suggests that gay travelers are not homogeneous, and that sexuality influences the travel behavior of a minority of gay men. Consequently, not all gay travelers or activities by these travelers can be labeled as “gay” tourism.     

THE TRANSFORMATION OF GENDER INTO CONVERSATIONAL ADVANTAGE

This article examines the relationship between gender and conversational power by treating as problematic the process through which a social position is transformed into conversational advantage. Using symbolic interactionism, it is argued that conversational power is exercised over the course of a role performance and is affected by the identities of the interactants and the context in which interaction occurs. This argument is evaluated by using conversational data from a same-sex dyadic role-playing exercise and by measures of gender identity. Findings indicate that regardless of a person's sex, the more "male like" his/her gender identity, the more likely he/she is to challenge statements made by alter. Concerning context, the more assertive alter's behavior, the more likely ego is to act in a similarly assertive manner. The relevance of these findings for the broader study of self, society, and conversational behavior is discussed.     

DEWEY'S CRITIQUE OF MARXISM

This paper examines the development of John Dewey's critique of Marxism. We trace the development of Dewey's critique from his early political writings and his political encounter with Leon Trotsky to his mature critique. We also examine how Dewey's concerns anticipate ideas expressed in the contemporary discussion of Marxian morality and how this discussion helps clarify Dewey's concerns.