The mystery of the missing middle-tenants: The “negative” case of fixed-term leasing and agricultural investment in fifteenth-century Tuscany

Theory and Society -     

Quantitative Risk Assessment from Farm to Fork and Beyond: A Global Bayesian Approach Concerning Food-Borne Diseases

A novel approach to the quantitative assessment of food-borne risks is proposed. The basic idea is to use Bayesian techniques in two distinct steps: first by constructing a stochastic core model via a Bayesian network based on expert knowledge, and second, using the data available to improve this knowledge. Unlike the Monte Carlo simulation approach as commonly used in quantitative assessment of food-borne risks where data sets are used independently in each module, our consistent procedure incorporates information conveyed by data throughout the chain. It allows "back-calculation" in the food chain model, together with the use of data obtained "downstream" in the food chain. Moreover, the expert knowledge is introduced more simply and consistently than with classical statistical methods. Other advantages of this approach include the clear framework of an iterative learning process, considerable flexibility enabling the use of heterogeneous data, and a justified method to explore the effects of variability and uncertainty. As an illustration, we present an estimation of the probability of contracting a campylobacteriosis as a result of broiler contamination, from the standpoint of quantitative risk assessment. Although the model thus constructed is oversimplified, it clarifies the principles and properties of the method proposed, which demonstrates its ability to deal with quite complex situations and provides a useful basis for further discussions with different experts in the food chain.     

Indigenous Elder Insights About Conventional Care Services in Alaska: Culturally Charged Spaces

Indigenous peoples around the world endure health and social disparities. In the United States, such disparities are typically ameliorated through conventional care services and organizations. Purpose: To examine points of tension that characterize culturally pluralistic care services in the United States, specifically Alaska, within context of Indigenous colonial histories. Design and Methods: The research design is ethnographic and multisited, comprising 12 months of fieldwork across urban, rural and remote village sites in Alaska. A conceptual lens that accounts for culturally diverse social spaces where relations of power are at stake frames research presented here. This work incorporates relational and participatory action research principles with Alaska Native Elders. Ethnographic evidence was collected through multiple methods, including field notes, documents, and interviews, with ethnographic analysis involving atlas.ti. Findings: Alaska Native Elders describe salient points of tension characterizing Alaska’s conventional care services through the following insights: generational curses-—a pain, prejudice on both sides—wounded, and value-systems clash—fighting. Conclusion: This article concludes with discussion about collective anxieties and implications for care services.     

Optimizing the Staffing and Routing of Small‐Size Hierarchical Call Centers

Multiple‐skill call centers propagate rapidly with the development of telecommunications. An abundance of literature has already been published on call centers. Here, we want to focus on centers that would typically occur in business‐to‐business environments; these are call centers that handle many types of calls but where the arrival rate for each type is low. To find an optimal configuration, the integrality of the decision variables is a much more important issue than for larger call centers. The present paper proposes an approach that uses elements of combinatorial optimization to find optimal configurations. We develop an approximation method for the evaluation of the service performance. Next, we search for the minimum‐cost configuration subject to service‐level constraints using a branch‐and‐bound algorithm. What is at stake is to find the right balance between gains resulting from the economies of scale of pooling and the higher cost or cross‐trained agents. The article shows that in most cases this method significantly decreases the staffing cost compared with configurations with only cross‐trained or dedicated operators.     

Organizational Form as a Mechanism to Involve Staff,Public and Users in Public Services: A Study of the Governance of NHS Foundation Trusts

In addition to introducing markets and market‐like structures into public services, New Labour wished to promote the involvement of users and the public in decision‐making in other ways than as individual consumers. One way was to involve the public in the governance of organizations. This could be done by removing public services from state control, and transferring them to mutual ownership; or by increasing public involvement in the governance of public bodies. NHS foundation trusts (FTs) were presented as mutuals. Our study shows FTs are not mutuals, as they continue to be owned by the state. Moreover, staff of FTs were generally not engaging with the new governance structures. In general, there was mixed experience of the new structures enabling governors to increase accountability of the hospitals to the public. On the other hand, having a membership did enhance the legitimacy of FTs, as opposed to other NHS organizations. The findings of the study are of current interest as the coalition government is continuing with the policy of FTs, and also encouraging mutuals and other forms of public involvement.     

Adverse selection,moral hazard and propitious selection

We propose a simple model with preference-based adverse selection and moral hazard that formalizes the cherry picking/propitious selection argument. This argument assumes that individuals differ in risk aversion, potentially resulting in more risk averse agents buying more insurance while being less risky. The propitious selection argument is summarized by two properties: regularity (more risk averse agents exert more caution) and single-crossing (more risk averse agents have a higher willingness to pay for insurance). We show that these assumptions are incompatible with a pooling equilibrium, and that they do not imply a negative correlation between risk and insurance coverage at equilibrium.

On a new goodness‐of‐fit process for families of copulas

A goodness‐of‐fit procedure is proposed for parametric families of copulas. The new test statistics are functionals of an empirical process based on the theoretical and sample versions of Spearman's dependence function. Conditions under which this empirical process converges weakly are seen to hold for many families including the Gaussian, Frank, and generalized Farlie–Gumbel–Morgenstern systems of distributions, as well as the models with singular components described by Durante [Durante ( 2007 ) Comptes Rendus Mathématique. Académie des Sciences. Paris, 344, 195–198]. Thanks to a parametric bootstrap method that allows to compute valid P‐values, it is shown empirically that tests based on Cramér–von Mises distances keep their size under the null hypothesis. Simulations attesting the power of the newly proposed tests, comparisons with competing procedures and complete analyses of real hydrological and financial data sets are presented. The Canadian Journal of Statistics 37: 80‐101; 2009 © 2009 Statistical Society of Canada     

DATA‐DRIVEN SMOOTH TESTS AND A DIAGNOSTIC TOOL FOR LACK‐OF‐FIT FOR CIRCULAR DATA

Two contributions to the statistical analysis of circular data are given. First we construct data‐driven smooth goodness‐of‐fit tests for the circular von Mises assumption. As a second method, we propose a new graphical diagnostic tool for the detection of lack‐of‐fit for circular distributions. We illustrate our methods on two real datasets.