Sign Restrictions,Structural Vector Autoregressions,and Useful Prior Information

This paper makes the following original contributions to the literature. (i) We develop a simpler analytical characterization and numerical algorithm for Bayesian inference in structural vector autoregressions (VARs) that can be used for models that are overidentified, just‐identified, or underidentified. (ii) We analyze the asymptotic properties of Bayesian inference and show that in the underidentified case, the asymptotic posterior distribution of contemporaneous coefficients in an n‐variable VAR is confined to the set of values that orthogonalize the population variance–covariance matrix of ordinary least squares residuals, with the height of the posterior proportional to the height of the prior at any point within that set. For example, in a bivariate VAR for supply and demand identified solely by sign restrictions, if the population correlation between the VAR residuals is positive, then even if one has available an infinite sample of data, any inference about the demand elasticity is coming exclusively from the prior distribution. (iii) We provide analytical characterizations of the informative prior distributions for impulse‐response functions that are implicit in the traditional sign‐restriction approach to VARs, and we note, as a special case of result (ii), that the influence of these priors does not vanish asymptotically. (iv) We illustrate how Bayesian inference with informative priors can be both a strict generalization and an unambiguous improvement over frequentist inference in just‐identified models. (v) We propose that researchers need to explicitly acknowledge and defend the role of prior beliefs in influencing structural conclusions and we illustrate how this could be done using a simple model of the U.S. labor market.     

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.     

Genes, longevity, and technology: meeting report from the 2nd conference on functional genomics of aging in Crete

Whole-genome sequences are now available, and methods have evolved for targeting, in parallel, each gene in a genome, offering for the first time the opportunity to study the entire dynamic network of genes involved in aging. At a recent conference in Hersonissos, Crete, around 200 internationally renowned experts gathered to discuss techniques and emerging results as the science of aging undergoes a shift toward systems biology.     

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.     

Association between overt and relational aggression and psychosocial adjustment in undergraduate college students

This study examined the relations between overt and relational aggression, social anxiety, loneliness, depressive symptoms, and alcohol and drug use in a sample of 287 undergraduate college students. Consistent with prior work, men reported engaging in more overt aggression than women. Contrary to our predictions, men also reported engaging in more relational aggression than women. Results also indicated that overt and relational aggression were positively associated with social anxiety, loneliness, depressive symptoms, alcohol use, and drug use for the overall sample. Hierarchical regression analyses showed positive relations between overt aggression and alcohol use for men and no relations between relational aggression and any psychosocial adjustment index. For women, overt aggression uniquely predicted social anxiety, loneliness, and depressive symptoms, whereas relational aggression uniquely predicted social anxiety, loneliness, depression, and alcohol and drug problems. Implications of these findings are discussed in terms of the role of peer aggression in students' psychosocial adjustment.     

Peer Victimization in Children with Learning Disabilities

This study examined the nature and psychosocial correlates of peer victimization in a clinical sample of children with Learning Disabilities (LD). A total of 303 patient charts were searched at a university child psychiatry clinic, and 77 participants met LD diagnostic criteria. Data collected included the Child Behavior Checklist (which contains items assessing peer victimization), Conners Parent Rating Scale, Revised Children’s Manifest Anxiety Scale, and Children’s Depression Inventory. Peer victimization was positively correlated with parent reports of withdrawal, anxiety, depressive symptoms, social problems, thought problems, attention problems, and disruptive behavior. Children with LDs who had comorbid psychiatric diagnoses reported a significantly higher amount of peer victimization than children without a comorbid psychiatric condition. Implications of this study regarding the role of peer victimization and healthy psychological adjustment among children with LDs are discussed.