Book Review Guns,Germs and Steel: The Fates of Human Societies. Jared Diamond. New York: W.W. Norton, 1997, 480 pp.

Population and Environment -     

An International Pooled Analysis for Obtaining a Benchmark Dose for Environmental Lead Exposure in Children

Lead is a recognized neurotoxicant, but estimating effects at the lowest measurable levels is difficult. An international pooled analysis of data from seven cohort studies reported an inverse and supra‐linear relationship between blood lead concentrations and IQ scores in children. The lack of a clear threshold presents a challenge to the identification of an acceptable level of exposure. The benchmark dose (BMD) is defined as the dose that leads to a specific known loss. As an alternative to elusive thresholds, the BMD is being used increasingly by regulatory authorities. Using the pooled data, this article presents BMD results and applies different statistical techniques in the analysis of multistudy data. The calculations showed only a limited variation between studies in the steepness of the dose‐response functions. BMD results were quite robust to modeling assumptions with the best fitting models yielding lower confidence limits (BMDLs) of about 0.1–1.0 μ g/dL for the dose leading to a loss of one IQ point. We conclude that current allowable blood lead concentrations need to be lowered and further prevention efforts are needed to protect children from lead toxicity.     

Mean estimation with data missing at random for functional covariables

In a missing-data setting, we want to estimate the mean of a scalar outcome, based on a sample in which an explanatory variable is observed for every subject while responses are missing by happenstance for some of them. We consider two kinds of estimates of the mean response when the explanatory variable is functional. One is based on the average of the predicted values and the second one is a functional adaptation of the Horvitz–Thompson estimator. We show that the infinite dimensionality of the problem does not affect the rates of convergence by stating that the estimates are root-n consistent, under missing at random (MAR) assumption. These asymptotic features are completed by simulated experiments illustrating the easiness of implementation and the good behaviour on finite sample sizes of the method. This is the first paper emphasizing that the insensitiveness of averaged estimates, well known in multivariate non-parametric statistics, remains true for an infinite-dimensional covariable. In this sense, this work opens the way for various other results of this kind in functional data analysis.     

French and British Top Managers' Understanding of the Structure and the Dynamics of Their Industries: a Cognitive Analysis and Comparison

This paper presents the findings of an exploratory study of the content of and differences between managerial frames of references with regard to the structure and dynamics of competitive environments. These frames of references are examined and compared at both the industry level and the country level; and the paper shows the influences of both industry and institutional structures and national culture on managerial thinking. It therefore contributes to the field of comparative management, as well as the growing interest in cognitive analysis in the field of management. The study is particularly significant since (a) its context is the rapidly changing industry environment of Europe, and (b) the managers are all involved in the development of strategies for their firms. Thirty three top managers (16 English and 17 French) were interviewed in four industries (brewing, car manufacturing, retail banking and book publishing) on their understanding of their industry and the strategy of their company. Content analysis of the transcribed interviews surfaces cognitive constructs which facilitate the identification of similarities and differences between managers, (a) within industries, (b) across industries, (c) within countries, (d) between countries and (e) between countries within the different industries. The analysis also provides means whereby the constructs can be represented in the form of cognitive maps.     

Robustness evaluation of multisite distributed schedule with perturbed virtual jobshops

A method for evaluating the robustness of medium term multisite distributed schedule is presented. The method of robustness evaluation is based on steps and tools associated with the conceptual model of a MultiSite Reactive Production Activity Control (MSR-PAC). The MSR-PAC makes it possible to study the sensitivity of the scheduled plans in presence of perturbations. These must be evaluated before being dispatched to the shop-floors. At present, to the best of the authors' knowledge, there is no means to make this evaluation in the distributed systems such as extended enterprise. The monitoring of errors is based on the discrepancy between the two flow-shape functions that model respectively the dynamics of the scheduled manufacturing orders and the state of the perturbed production. The MSR-PAC is based on a multisite agent system and on the monitoring of the perturbed virtual jobshops. The method can also be used for controlling short term distributed production activities.     

Estimation of the Force of Infection from Current Status Data Using Generalized Linear Mixed Models

Based on sero-prevalence data of rubella, mumps in the UK and varicella in Belgium, we show how the force of infection, the age-specific rate at which susceptible individuals contract infection, can be estimated using generalized linear mixed models (McCulloch & Searle, 2001). Modelling the dependency of the force of infection on age by penalized splines, which involve fixed and random effects, allows us to use generalized linear mixed models techniques to estimate both the cumulative probability of being infected before a given age and the force of infection. Moreover, these models permit an automatic selection of the smoothing parameter. The smoothness of the estimated force of infection can be influenced by the number of knots and the degree of the penalized spline used. To determine these, a different number of knots and different degrees are used and the results are compared to establish this sensitivity. Simulations with a different number of knots and polynomial spline bases of different degrees suggest - for estimating the force of infection from serological data - the use of a quadratic penalized spline based on about 10 knots.     

Le modèle de « l'État-stratège » : genèse d'une forme organisationnelle dans l'administration française

Since the 1990s, a new organisational form of the administrative system in France has been steadily redefining relations between central administrations and local state units. Labelled “the steering state” or the “managerial state”, this new paradigm hinges on separating the strategic functions of steering and controlling the state from the operational functions of execution and policy implementation. The making of this new form of state organization involves two parallel processes: political and cognitive. For one thing, the adoption of concrete measures for “government at distance” results from power struggles between three major ministries (Home Office, Budget and Civil Service). For another, a new legitimate “categorization of the state” is being formed in the major committees involved in the reform process of the 1990s; it is borne by top civil servants and inspired by the ideas of New Public Management. — Special issue: New patterns of institutions.     

Disappointment without prior expectation: a unifying perspective on decision under risk

The central idea of Disappointment theory is that an individual forms an expectation about a risky alternative, and may experience disappointment if the outcome eventually obtained falls short of the expectation. We abandon the hypothesis of a well-defined prior expectation: disappointment feelings may arise from comparing the outcome received with anyof the gamble’s outcomes that the individual failed to get. This leads to a new, general form of Disappointment model. It encompasses Rank Dependent Utility with an explicit one-parameter probability transformation, and Risk-Value models with a generic risk measure including Variance, providing a unifying behavioral foundation for these models. JEL Classification D80 . D81     

Contents Volume 54

Volume Contents

Contents Volume 54