Nonstationarity and Level Shifts With an Application to Purchasing Power Parity

This study considers testing for a unit root in a time series characterized by a structural change in its mean. The analysis is in the spirit of Perron (1990a), who showed that the existence of such a shift in a stationary time series biases the usual tests for a unit root toward nonrejection. The approach is, however, different given that we suppose the date of the change to be unknown. The statistic of interest is then the minimal t statistic over all possible breakpoints in regressions similar to those proposed by Perron (1990a). Other related statistics are also discussed. We derive and tabulate the asymptotic distributions of interest. Most of the emphasis, however, is given to the tabulation of finite-sample critical values using simulation experiments. Particular attention is given to the effect, on the finite-sample critical values, of various procedures to select the appropriate order of the estimated autoregressions. We apply the tests to analyze the issue of purchasing power parity between the United States and the United Kingdom and also between the United States and Finland, whose real exchange rates are characterized by apparent shifts in level when using particular price indexes.     

Constraint-based model for the cyclic multi-hoists scheduling problem

This article presents a method for the resolution of a material handling scheduling problem. The case studied is a real industrial problem. It consists of finding a cyclic schedule for hoist movements in a treatment surface shop. In this kind of facility, several hoists are used for all the handling operations and they have to share common zones. Then it is necessary to control that there is no collision. The mathematical formulation of the problem is based on a combination of disjunctive constraints. The constraints describe either movement schedule or collision avoidance. The resolution procedure presented identifies all the collision configurations and then uses a branch and bound-like algorithm to find the optimal solution of a given problem. The language chosen for our implementation is the constraint logic programming language: Prolog IV, which is able to solve constraints with rational variables. It actively uses the constraint propagation mechanism that can be found in several languages.     

Science news in the European dailies,the invisible network of the agenda setting

A survey of the development of press coverage of scientific and technical information in the main European dailies¹, reveals three major trends—a general explosion of coverage in the Community countries studied, an increasingly specialized body of science writers and, finally, a lack of control of the networks that communicate scientific information and ensure its recognition at an international level. Even though the subject matter is mainly international, science reporting in the daily press is still in fact a question of “jobbing”; and expresses all the cultural diversity of Europe.     

Evaluation of a Sexual Abuse Prevention Workshop in a Multicultural,Impoverished Urban Area

Participants in the ESPACE sexual abuse prevention workshop were in grades 1 through 4 and attended three Montreal, Canada, public schools in low socioeconomic areas. The sample was culturally diverse, with half born outside of Canada. An evaluation was conducted to explore the effects associated with participating in the workshop and the effects of booster sessions conducted two years later. Outcomes included knowledge gained, the ability to offer behavioral responses to abusive situations, peer victimization, sense of safety, empathy, self-efficacy, and support. Results revealed that participants in this sample obtained low scores on measures of sexual abuse knowledge and that short booster sessions that elicit children's recall of the learned material might produce greater improvements.     

Interweaving Objects,Gestures, and Talk in Context

In a large French hospital, a group of professional experts (including physicians and software engineers) are working on the computerization of a blood-transfusion traceability device. By focusing on a particular moment in this slow process of design, we analyze their collaborative practices during a work session. The analysis takes a praxeological and interactionist approach and is inspired by discussions on the role of artifacts in social practices currently developed within various research frameworks in this field: activity theory, distributed cognition, conversation analysis, and actor network theory. After a brief presentation of the place of objects and artifacts in these ways of approaching action and human cognition, we show how the collective activity analyzed here is generated by the interweaving of discursive, gestural, and artifactual resources.     

Reduced inhibitory control predicts persistence in laboratory slot machine gambling

Impairments in inhibitory control characterize a range of addictive behaviours including gambling disorder. This study investigated the relationship between a neuropsychological measure of inhibitory control and behaviour on a simulated slot machine that included a measure of gambling persistence, in a non-clinical sample of regular gamblers. Regular gamblers (n = 75) performed a laboratory slot machine task for 30 trials where they could win real money, followed by a persistence phase under extinction (i.e. without wins). Participants also completed a stop-signal task, along with measures of gambling-related cognitions, social desirability, and symptoms of disordered gambling. In hierarchical regression models, reduced inhibitory control was found to predict greater persistence and a higher subjective desire to play again after both wins and near-misses (i.e. unsuccessful outcomes close to the jackpot). These data illustrate the impact of low inhibitory control on relevant behavioural tendencies in a group of regular gamblers. Our results help elucidate a cognitive process that may contribute to problem gambling, with implications for screening and treatment.     

Cooperative provision of indivisible public goods

A community faces the obligation of providing an indivisible public good that each of its members is able to provide at a certain cost. The solution is to rely on the member who can provide the public good at the lowest cost, with a due compensation from the other members. This problem has been studied in a non-cooperative setting by Kleindorfer and Sertel (J Econ Theory 64:20–34, 1994). They propose an auction mechanism that results in an interval of possible individual contributions whose lower bound is the equal division. Here, instead we take a cooperative stand point by modelling this problem as a cost sharing game that turns out to be a ‘reverse’ airport game whose core is shown to have a regular structure. This enables an easy calculation of the nucleolus that happens to define the upper bound of the Kleindorfer–Sertel interval. The Shapley value instead is not an appropriate solution in this context because it may imply compensations to non-providers.     

Socioeconomic determinants of the need for personal assistance reported by community-dwelling elderly: Empirical evidence from a French national health survey

A bivariate probit model with sample selection is used to estimate the conditional probability of reporting a need for personal assistance (NPA) with at least one activity of daily living among French community-dwelling elderly. 71.8% of men and 77.3% of women reported impairments and among those who reported impairments, 7.5% of men and 10.8% of women reported NPA. NPA is associated not only with age (i.e., the oldest individuals, for women only) and health status (such as a specific type of impairment), but also with socioeconomic (living with intermediate income; living with someone, partner or other) and environmental factors (having and using assistive technologies).