Que faut‐il voir dans les écarts de rémunération entre les travailleurs immigrés des pays du Golfe: l'effet d'a priori patronaux ou la simple conséquence de coûts d'opportunité différents?

Les auteurs s'intéressent aux disparités salariales entre les différents groupes de migrants qualifiés qui travaillent en grand nombre pour le secteur privé dans les États du Conseil de coopération du Golfe. Ils se demandent notamment si la prime salariale des Occidentaux (par rapport aux travailleurs venus d'Asie ou d'autres États arabes) découle d'éventuels a priori des employeurs. L'analyse, qui repose sur des données de 2012–2014 et sur deux méthodes de décomposition classiques, infirme l'hypothèse: les caractéristiques observables relatives à la productivité expliquent entre un tiers et trois quarts des écarts; le coût d'opportunité de la migration, supérieur pour les Occidentaux, explique la portion restante.     

American Indian Perceptions of Paternal Responsibility

Using data from the Fragile Families and Child Wellbeing Study, this study examined the issue of American Indian nonresident father rights and obligations. Findings revealed that both American Indian mothers and fathers supported visitation rights, but decision-making rights were not highly supported unless the father was paying child support. Both American Indian parents were similar in their views regarding paternal responsibilities. Therefore, while general father involvement intervention strategies may work for American Indians, it is important for practitioners to explore how American Indians define paternal involvement and to what extent they are willing to allow the nonresident father to participate in all aspects of the child's life.     

Conservative linear programming with mixed multiple objectives

In an ordinary linear program a single objective vector is constructed and one attempts to choose a decision vector to optimize this objective. Often multiple criteria exist or exact estimates for the components of a single objective vector are not entirely clear. For these cases a conservative decision-maker may want to choose an alternative that maximizes the objective value under the worst foreseeable circumstances. Herein we develop a unified framework for applying the maximin criterion to problems with various degrees of uncertainty attached to the objective vector. Three cases are solved via linear programming: (1) Complete Information, (2) Partial Information, and (3) Total Ignorance. It is shown that the functional value of the maximin solution decreases in a convex manner with increasing uncertainty. In addition certain relationships between maximin and efficient solutions are provided. Finally, an extension to integer constrained decision variables is presented.     

Fossil fuel supplies simulation 1972–1979

Fossil fuels are an important source of energy for Ontario Hydro and purchases exceed $100 million per year. This paper describes a computer simulation of the inventory situation over an eight-year period, which is being used to assess the relationship between order flexibility and the target carry-over stocks at the beginning of each shipping season. A simple way of presenting the results for management evaluation is illustrated. Variations of the model are used to assess random influences, such as strikes, and to determine the economic balance between holding costs and stock-outs.     

Effects of beverage-specific alcohol consumption on drinking behaviors among urban youth

Alcoholic beverage consumption among high school students has shifted from beer to liquor. The current longitudinal study examined the effects of beverage-specific alcohol use on drinking behaviors among urban youth. Data included 731 adolescents who participated in Project Northland Chicago and reported consuming alcohol in 7th grade. Logistic regression tested the effects of beverage-specific use on consequences (e.g., alcohol use in the past month, week, heavy drinking, and ever drunkenness). Compared to wine users, adolescents who reported drinking hard liquor during their last drinking occasion had increased odds of alcohol use during the past month (OR = 1.44; 95% CI = 1.01-2.05), past week (OR = 3.37; 95% CI = 1.39-8.18), and ever drunkenness (OR = 1.56; 95% CI = 1.07-2.29). Use of hard liquor was associated with increased risk of alcohol-related consequences. Early selection of certain alcoholic beverages (e.g., hard liquor) may result in negative health outcomes and problematic alcohol use over time.     

Contemporary options for longitudinal follow-up: lessons learned from a cohort of urban adolescents

This study reports efforts to locate and survey participants in Project Northland Chicago (PNC), a longitudinal, group-randomized trial of an alcohol preventive intervention for racial/ethnic minority, urban, early-adolescents, 3-4 years following the end of the intervention. Data were collected annually among students from 6th-8th grade and then at age 17-18. Tracking procedures were used to maintain contact with participants and data collection consisted of three phases: (1) Internet- and mail-based surveys; (2) in-school survey administration; and (3) courier service delivery. Contact was lost with 11% of this urban cohort from the end of the PNC intervention activities through these longterm follow-up efforts, as indicated by returned locating postcards. Fifty-three percent of the cohort responded to the survey, the majority completing in Phase 1 of our data collection. Additional school-based and courier-delivery efforts increased our response rate by 11.5%. Costs per completed survey were $118 in Phase 1, $166 in Phase 2, and $440 in Phase 3. This study illustrates that it is possible to track and follow-up a high-risk cohort as they progress through adolescence, even with minimal efforts in intervening years. Lessons learned from this study may inform future efforts to track and collect longitudinal data among high-risk populations.