Trajectories of team and individual sports participation in childhood and links with internalizing problems

The purpose of this 5-year longitudinal study is to identify trajectories of team and individual sports participation in childhood, and to compare these trajectories on different types of internalizing problems. Parents reported their children's annual sports participation from the ages of 6–10 (n = 785) and teachers reported internalizing problems (depression, anxiety, social withdrawal) at the beginning and at the end of this period. The study used latent class growth analyses to identify two trajectories of team sports and two trajectories of individual sports participation were identified: (1) high participation, and (2) low participation. Considering baseline level of internalizing problems and gender, children in the high participation team sports trajectory show significantly fewer depression, anxiety, and social withdrawal behaviors at age 10 than those in the low participation team sports trajectory. No differences between individual sports trajectories were observed. Comparison with joint trajectory groups partially confirmed these results but also showed that sustained participation in multiple individual sports could also be linked to decreased anxiety. Our findings suggest that participation in team sports should be encouraged to promote certain aspects of children's mental health.     

The worldwide maritime network of container shipping: spatial structure and regional dynamics

Port and maritime studies dealing with containerization have observed traffic concentration and dispersion throughout the world. Globalization, intermodal transportation, and technological revolutions in the shipping industry have resulted in both network extension and rationalization. However, lack of precise data on inter‐port relations prevent the application of wider network theories to global maritime container networks, which are often examined through case studies of specific firms or regions. In this article, we present an analysis of the global liner shipping network in 1996 and 2006, a period of rapid change in port hierarchies and liner service configurations. While we refer to literature on port system development, shipping networks, and port selection, the article is one of the only analyses of the properties of the global container shipping network. We analyse the relative position of ports in the global network through indicators of centrality. The results reveal a certain level of robustness in the global shipping network. While transhipment hub flows and gateway flows might slightly shift among nodes in the network, the network properties remain rather stable in terms of the main nodes polarizing the network and the overall structure of the system. In addition, mapping the changing centrality of ports confirms the impacts of global trade and logistics shifts on the port hierarchy and indicates that changes are predominantly geographic.     

WebStress: A web interface to explore a multidatabase bibliographic corpus on occupational stress

A bibliographic study on a multidisciplinary subject, such as occupational stress, requires a multidatabase query facility. Given this, we searched eight databases belonging to different fields (medicine, psychology, etc.) and from different countries. Thus, more than 26000 references on occupational stress were gathered. A bibliographic corpus of this sort is unusable because of the heterogeneous format of the records and the number of duplicate entries. Considering the limitations of commercial programs, we have developed a system, called WebStress, for reformatting the data and removing duplicates. The huge number of references and the research needs of updating and searching have necessitated the addition of several other functions to WebStress. Therefore WebStress comprises a web interface that makes it possible to search the corpus with advanced features (using clustering, a specialized thesaurus on stress and Boolean queries). In addition to the usual bibliographic queries on a specific database such as Medline, WebStress provides bibliometric analysis of the corpus, which might contribute to a detailed analysis on occupational stress in order to highlight the networks of researchers and to find the main topics studied in this area. WebStress is not yet available to researchers in general. It is being further developed, and also permission needs to be obtained from the eight commercial bibliographic databases that it consults.     

Internal Working Models of Attachment and Postdivorce Coparent Relationships

Stable coparenting relationships postdivorce have been shown to combat the negative effects on child development. There are three types of coparental relationships postdivorce: stable, conflicted and cut off. Each type of interaction has different effects on the children and other family members, with the stable coparent relationship being the most functional. Attachment theory explains the differences between the coparenting styles. Individuals in stable coparent relationships are more likely to have a secure internal working model; conflicted coparents are more likely to have an anxious-ambivalent internal working model; and disengaged coparents are more likely to have an avoidant internal working model.     

BRAIN DRAIN IN GLOBALIZATION: A GENERAL EQUILIBRIUM ANALYSIS FROM THE SENDING COUNTRIES' PERSPECTIVE

According to the economic literature, high‐skilled emigration may either harm or benefit developing economies. Recent research highlighted several positive and negative channels through which the brain drain operates. This paper aims at evaluating the relative magnitudes of various brain drain channels and quantifying their global impact on migrants' sending countries. For this purpose, we develop a 10‐region general equilibrium model of the world economy characterized by overlapping‐generations dynamics. Our findings suggest that the short‐run impact of brain drain on resident human capital is extremely crucial, as it affects not only the number of high‐skilled workers available to domestic production, but also the sending economy's capacity to innovate/adopt modern technologies. This latter effect is particularly important in globalization, where capital investments are made in places with high production efficiencies. Hence, despite positive feedback effects, those countries facing prevalent high‐skilled emigration are the most candid victims to brain drain. (JEL F22, J24, O57)     

Stability of feature selection in classification issues for high-dimensional correlated data

Handling dependence or not in feature selection is still an open question in supervised classification issues where the number of covariates exceeds the number of observations. Some recent papers surprisingly show the superiority of naive Bayes approaches based on an obviously erroneous assumption of independence, whereas others recommend to infer on the dependence structure in order to decorrelate the selection statistics. In the classical linear discriminant analysis (LDA) framework, the present paper first highlights the impact of dependence in terms of instability of feature selection. A second objective is to revisit the above issue using a flexible factor modeling for the covariance. This framework introduces latent components of dependence, conditionally on which a new Bayes consistency is defined. A procedure is then proposed for the joint estimation of the expectation and variance parameters of the model. The present method is compared to recent regularized diagonal discriminant analysis approaches, assuming independence among features, and regularized LDA procedures, both in terms of classification performance and stability of feature selection. The proposed method is implemented in the R package FADA, freely available from the R repository CRAN.     

European System of Accounts: The French Case

The 1995 European System of Accounts (1995 ESA), an adapted version of the United Nations System of National Accounts (1993 SNA), will be applied in most European countries. This research note shows that the empirical knowledge of the nonprofit sector is not improved in this change. We first review the treatment of the nonprofit organizations in 1968 SNA, and then discuss the 1993 SNA and 1995 ESA approaches, which do not clear up many conceptual difficulties. The classification of the private nonprofit institutions serving households by the French statistical office is also presented and criticized. A way forward through the use of a satellite account system is proposed.     

Negative Dependence in Sampling

Abstract. The strong Rayleigh property is a new and robust negative dependence property that implies negative association; in fact it implies conditional negative association closed under external fields (CNA+). Suppose that and are two families of 0‐1 random variables that satisfy the strong Rayleigh property and let . We show that {Z_i} conditioned on is also strongly Rayleigh; this turns out to be an easy consequence of the results on preservation of stability of polynomials of Borcea & Brändén (Invent. Math., 177, 2009, 521–569). This entails that a number of important π ps sampling algorithms, including Sampford sampling and Pareto sampling, are CNA+. As a consequence, statistics based on such samples automatically satisfy a version of the Central Limit Theorem for triangular arrays.     

PORK‐BARREL POLITICS,TARGETABLE POLICIES,AND FISCAL FEDERALISM

This article utilizes a simple model of redistributive politics with jurisdictional specific local projects to analyze the inefficiencies that arise under differing levels of targetability in both taxes/transfers and local projects. The ability to tactically target taxes/transfers and/or local projects leads political parties to engage in pandering to favored groups. However, in equilibrium, we find that greater targetability in the set of available policies actually intensifies the competition between the political parties and so increases efficiency in the provision of local projects. (JEL: D72, H41)