Robustness of Risk Maps and Survey Networks to Knowledge Gaps About a New Invasive Pest

In pest risk assessment it is frequently necessary to make management decisions regarding emerging threats under severe uncertainty. Although risk maps provide useful decision support for invasive alien species, they rarely address knowledge gaps associated with the underlying risk model or how they may change the risk estimates. Failure to recognize uncertainty leads to risk‐ignorant decisions and miscalculation of expected impacts as well as the costs required to minimize these impacts. Here we use the information gap concept to evaluate the robustness of risk maps to uncertainties in key assumptions about an invading organism. We generate risk maps with a spatial model of invasion that simulates potential entries of an invasive pest via international marine shipments, their spread through a landscape, and establishment on a susceptible host. In particular, we focus on the question of how much uncertainty in risk model assumptions can be tolerated before the risk map loses its value. We outline this approach with an example of a forest pest recently detected in North America, Sirex noctilio Fabricius. The results provide a spatial representation of the robustness of predictions of S. noctilio invasion risk to uncertainty and show major geographic hotspots where the consideration of uncertainty in model parameters may change management decisions about a new invasive pest. We then illustrate how the dependency between the extent of uncertainties and the degree of robustness of a risk map can be used to select a surveillance network design that is most robust to knowledge gaps about the pest.     

Comparison between the rates of convergence of extremes under linear and under power normalization

By using the theory of the second-order regular variation, we study the rates of the weak convergence of the maximum order statistics under power normalization. The exact rates are obtained in the uniform metric and the total variation metric. The relationship between the rates of convergence under linear and under power normalization is derived. Some illustrative examples are given for comparing the rates of convergence.     

Calibration of FI‐ISK,an Invasiveness Screening Tool for Nonnative Freshwater Invertebrates

The Freshwater Invertebrate Invasiveness Scoring Kit (FI‐ISK) is proposed as a screening tool for identifying potentially invasive freshwater invertebrates. FI‐ISK was adapted from the Fish Invasiveness Scoring Kit (FISK) of Copp, Garthwaite, and Gozlan, which is an adapted form of the Weed Risk Assessment (WRA) of Pheloung, Williams, and Halloy. Initial assessments using FI‐ISK, which include confidence (certainty/uncertainty) rankings by the assessor to each response, were calibrated to determine the most appropriate score thresholds for classifying nonnative species into low‐, medium‐, and high‐risk categories, using both the original medium‐to‐high risk threshold scores for the WRA (i.e., ≥6) and for FISK (i.e., ≥19). Patterns of the assessor's confidence, when making the responses during the FI‐ISK assessments, were also examined. Using receiver operating characteristic (ROC) curves, FI‐ISK was shown to distinguish accurately (and with statistical confidence) between potentially invasive and noninvasive species of nonnative crayfish (Decapoda: Astacidae, Cambaridae, Parastacidae), with the statistically appropriate threshold score for high‐risk species scores being ≥16. FI‐ISK represents a useful and viable tool to aid decision‐ and policymakers in assessing and classifying freshwater invertebrates according to their potential invasiveness.     

The Political Role of Service Delivery in State‐Building: Exploring the Relevance of European History for Developing Countries

Concerns about failed and fragile states have put state‐ and nation‐building firmly on the academic and policy agenda, but the crucial role of public services in this process has remained underexplored. The 1960s and ‘70s generated a substantial set of literature that is largely missing from current writing. It identified state penetration, standardisation and accommodation as key processes in the state‐ and nation‐building sequence. This article analyses these three processes in Western Europe in the seventeenth to nineteenth centuries, and the role of public services therein, to explore how they may help us to understand the success and failure of state‐ and nation‐building in developing countries and fragile states.     

Do single mothers in the United States use the Earned Income Tax Credit to reduce unsecured debt?

The Earned Income Tax Credit (EITC) is a refundable credit for low-income workers mainly targeted at families with children. This study uses the Survey of Income and Program Participation’s topical modules on Assets and Liabilities to examine associations between the EITC expansions during the early 1990s and the unsecured debt of the households of single mothers. We use two difference-in-differences comparisons over the study period 1988–1999, first comparing single mothers to single childless women, and then comparing single mothers with two or more children to single mothers with exactly one child. In both cases we find that the EITC expansions are associated with a relative decline in the unsecured debt of affected households of single mothers. While not direct evidence of a causal relationship, this is suggestive evidence that single mothers may have used part of their EITC to limit the growth of their unsecured debt during this period.     

The American Way

Media consolidation and convergence have increasingly changed the way individuals as both consumers and citizens access, process, and communicate information at the local, national, and global levels. Media industries and institutions influence public perception and occupy our time at work and at home more and more. Media literacy has become recognized as a twenty-first-century skill necessary for civic competence and the development of informed, responsible citizens. Although it has long been established in the curricula of other nations, it is relatively new in the United States. Media literacy is not simply teaching with media—rather, it entails teaching about media. Key frameworks such as the Text, Audience, and Production (TAP) model, which is explained in this article, can be used to help students systematically analyze and evaluate the wide range of media texts they are exposed to on a daily basis. The author discusses how media literacy is also compatible with several of the major strands identified by the National Council for the Social Studies and can be facilitated by the growing range of resources available to teachers.     

Transformation and Smoothing in Sample Survey Data

Abstract. We consider model‐based prediction of a finite population total when a monotone transformation of the survey variable makes it appropriate to assume additive, homoscedastic errors. As the transformation to achieve this does not necessarily simultaneously produce an easily parameterized mean function, we assume only that the mean is a smooth function of the auxiliary variable and estimate it non‐parametrically. The back transformation of predictions obtained on the transformed scale introduces bias which we remove using smearing. We obtain an asymptotic expansion for the prediction error which shows that prediction bias is asymptotically negligible and the prediction mean‐squared error (MSE) using a non‐parametric model remains in the same order as when a parametric model is adopted. The expansion also shows the effect of smearing on the prediction MSE and can be used to compute the asymptotic prediction MSE. We propose a model‐based bootstrap estimate of the prediction MSE. The predictor produces competitive results in terms of bias and prediction MSE in a simulation study, and performs well on a population constructed from an Australian farm survey.     

Individual Participation in Collective Action in the Context of a Caribbean Island State: Testing the Effects of Multiple Dimensions of Social Capital

This article presents the findings of a case study examining the relationship between social capital and individual participation in collective action on a Caribbean island recovering from devastation inflicted by Hurricanes Ivan and Emily. Using data drawn from 114 residential surveys on the island of Carriacou, Grenada, over the summer of 2006, we empirically test social capital as a predictor of individual participation in both formal and informal civic events. In addition, we further the theoretical development of the concept of social capital by independently testing the relationships between its multiple dimensions, specifically social networks; interpersonal trust; and norms of reciprocity. We find that associational membership and age are the two strongest predictors, while interpersonal trust, gender, and marital status are also significant. Our path analysis reveals that there is not a significant direct effect between associational membership and interpersonal trust, suggesting that the two dimensions may have independent, yet complementary, influences. This study sheds light on factors influencing citizen participation in “civic” forms of collective action in a developing region of the world, while demonstrating the multidimensional nature of social capital.     

Cognitive and Affective Factors Which Influence Downtown Behaviors

Abstract

Data collected on perceptions of downtown Atlanta are used to explore the impact of cognitive and affective assessments of place on the frequency with which individuals go downtown for shopping, business or professional services, and for entertainment activities. Findings include: (1) social background variables generally exert only weak effects on cognitive and affective responses to downtown Atlanta; (2) affective identification with downtown exerts a positive, significant, and powerful effect on the frequency of using downtown for shopping and business activities; (3) non-Whites, city residents, and singles are more likely to go downtown for entertainment activities than Whites, suburbanites, and married respondents; and (4) images of downtown, affective identification, and positive assessments of downtown municipal services encourage participation in downtown entertainment activities. The analysis strongly suggests that behaviors are influenced by the meanings and evaluations people create for an area.     

Puerto rican drug users’ experiences of physical and sexual abuse: Comparisons based on sexual identities

This study integrates the results of quantitative and qualitative methods to elucidate the association between sexual identity and physical and sexual abuse among Puerto Rican drug users. A structured questionnaire was administered to 800 subjects in New York and 399 in Puerto Rico. A total of 93 subjects (7.9%) self‐identified as homosexual or bisexual. Gay males were significantly more likely than heterosexual males to report first occurrence of physical abuse by a family member in childhood. Both gay and bisexual males were more likely than their heterosexual counterparts to report first experiencing unwanted sex in childhood and intimate partner physical abuse later in life. Lesbians were more likely than female heterosexuals to report unwanted sex in childhood. Qualitative data were collected through in‐depth life histories with 21 subjects and suggest that gay and lesbian subjects perceive antihomosexual prejudice on the part of family members as one cause of childhood physical and sexual abuse.