Semiparametric estimation in single index Poisson regression: a practical approach

In a single index Poisson regression model with unknown link function, the index parameter can be root- n consistently estimated by the method of pseudo maximum likelihood. In this paper, we study, by simulation arguments, the practical validity of the asymptotic behaviour of the pseudo maximum likelihood index estimator and of some associated cross-validation bandwidths. A robust practical rule for implementing the pseudo maximum likelihood estimation method is suggested, which uses the bootstrap for estimating the variance of the index estimator and a variant of bagging for numerically stabilizing its variance. Our method gives reasonable results even for moderate sized samples; thus, it can be used for doing statistical inference in practical situations. The procedure is illustrated through a real data example.     

Les apories de la solidarité familiale Contribution à la sociologie des configurations de justice entre les familles et l’État, dans le cas français

Despite its many meanings, “solidarity” has once again become current in French to describe macro as well as microsocial relations. Social relations in and outside the family have not always been understood as instances of solidarity. But is this solidarity the same as the one established by the welfare state? Forms of family solidarity that have risen in esteem over the past two decades are “deconstructed”. The conditions for family solidarity are examined; and conceptual paradoxes, described. This approach suggests that family solidarity, as this concept is normally used, mixes together several systems of justice that should be clearly distinguished, especially if we want to put this phrase to a judicious social use.     

Labor Supply of Older Men: Does Social Security Matter?

This article presents evidence of a negative and significant relationship between the level of Social Security wealth and the labor force participation of older men. The empirical analysis utilizes a panel data set containing participation, wage, and Social Security information for cohorts defined by birth year and educational attainment from 1967 to 1996. Increases in Social Security wealth levels are found capable of explaining most of the observed decline in labor force participation rates of older men since 1967.     

Exposure of Contractors to Chemical Pollutants During the Maintenance Shut-Down of a Chemical Plant

The exposure of employees of different contracting firms to chemical pollutants was assessed during the five-week biennial maintenance shut-down of an isocyanate (TDI) synthesis plant. This assessment was mainly based on personal sampling, but work-related constraints occasionally required that area samples be used instead. Many tasks were carried out during the shut-down procedure (dismantling of reactors, installation of insulation, refection of kilns, cleaning, painting, electricity, etc.), thereby causing the employees of the contracting firms to be exposed to different kinds of pollutants, including products used or manufactured in the process (solvents, TDI and its synthesis intermediates), and products specific to the contractors' activity (welding fumes, crystalline silica, mineral fibers of heat insulation). The highest level of exposure (mainly to TDI) was found for the mechanical engineering activities undertaken during the dismantling of reactors and for cleaning activities. It was demonstrated that there was much variability in day-to-day exposure levels, and occasionally in the exposure levels encountered during a given shift. Cases of concomitant exposure to TDI (mainly short-term exposures) and other pollutants due to simultaneous activities from different tasks in the same area (co-activity) were also observed. Both the need for, and limitations of personal protective equipment (mainly respiratory) are stressed. Special emphasis is put on the responsibility of the owner of the facilities in helping the contractors in the organization of a health and safety policy.     

Virtual Time

Like space, time takes on different characteristics in the digitized city. The Internet has contributed to a new way of problematizing time as embodied in human agency and social institutions, a time that is produced on a global scale, irrespective of time zones. This essay examines the contours, content and deployment of virtual time and of the cyberweek that it makes possible. It contrasts real time with virtual time to show the malleability of the latter, examines the ways in which the collapse of temporal boundaries and the compression of time-distance have manifested themselves in the cybertiming and flexitiming of the civil week, explores the global and local aspects of the cyberweek, and analyses the practical ramifications of virtual time in the daily life of the digital city.     

Gambling over the life course and treatment-seeking

The purpose of this study is to investigate change in gambling behaviours over the life course, and, correspondingly, the treatment-seeking behaviours of 86 people who met the criteria for at-risk (participants endorsing two to four items on the South Oaks Gambling Screen [SOGS]) and problem gamblers (participants endorsing five or more items on the SOGS) over the last five years. Data were obtained from informants during semi-structured interviews using Structured Clinical Interview for DSM-IV axis I and axis II disorders (SCID I and II), SOGS and treatment-seeking interviews. The results showed three groups of gambling behaviours over the life course. A first group started gambling early on and continued participating in recreational gambling until its participants were between 40 and 50 years of age, during which time they became problem gamblers. A second group transitioned from recreational gambling to problem gambling over a short period of time; its participants were aged between 40 and 50. Lastly, a third group which was exposed to gambling later on in life, mostly after retirement, developed gambling problems quickly. Psychopathology was prevalent in all groups, given that 98% suffered from a mental health problem during their life, and 62% within the last six months. Participants who made use of the services available mostly turned to medical and specialized mental services for brief periods, usually when in crisis. In terms of problem gambling, the results argue in favour of maintaining dedication toward treatment, especially in the presence of co-morbidity.     

Manufacturing feature-based cost management system: a case study in Brazil

Feature costing is a topic of recent discussion related to cost management systems (CMSs) aimed at understanding how product features influence production process costs. It raises as a key issue in mass customisation environments where a single product model can present hundreds of menu options. In this study, we explore the concept of feature costing beyond the use of activity-based costing (ABC). We propose a CMS based on features and common elements as costing objects instead of products. In our model, we use the unit of production effort method to organise the direct manufacturing costs, ABC method to address the indirect cost and the standard methods to compute raw materials costs. We illustrate the method in the production of bus seats in a Brazilian manufacturing company. This study gives different perspectives to the international academic community on the use of a different CMS used by many Brazilian companies.