Degree-based goodness-of-fit tests for heterogeneous random graph models: Independent and exchangeable cases

The degrees are a classical and relevant way to study the topology of a network. They can be used to assess the goodness of fit for a given random graph model. In this paper, we introduce goodness-of-fit tests for two classes of models. First, we consider the case of independent graph models such as the heterogeneous Erdös-Rényi model in which the edges have different connection probabilities. Second, we consider a generic model for exchangeable random graphs called the W-graph. The stochastic block model and the expected degree distribution model fall within this framework. We prove the asymptotic normality of the degree mean square under these independent and exchangeable models and derive formal tests. We study the power of the proposed tests and we prove the asymptotic normality under specific sparsity regimes. The tests are illustrated on real networks from social sciences and ecology, and their performances are assessed via a simulation study.     

Impact of soil compaction on soil biodiversity – does it matter in urban context?

Soil invertebrates are poorly studied in an urban context. Here we examine soil compaction in an urban environment, focusing on its persistence and its impact on biodiversity. This is achieved by studying a sensitive taxon, the collembolan (springtails). Soil core samples were taken in different location of a residential neighbourhood under construction, and collembolan species were extracted using a Berlese-Tullgren funnel. Soil compaction was determined by measuring bulk density. We documented soil compaction, ranging from 1 g/cm3 to 1.6 g/cm3. While collembolans are normally affected by compaction, such an effect was not observed in terms of species diversity, which remains relatively constant under all compaction levels. However, compaction was correlated with differences in the structure of collembolan communities. Indeed, we were able to discriminate different levels of compaction using collembolan community data alone. Moreover, this study confirms that compaction decreases with time. However, differences in species community structure can be observed one year after the end of the disturbance. Finally, we provide some insights into the reality of soil compaction in an urban environment, and highlight that the classical biodiversity indices may be insufficient for assessing the impact of an environmental disturbance, and that more detailed analyses at the community level may be very useful, or even indispensable.     

Welfare reform and interstate migration of poor families

The thesis of this study is that as a result of increased inequalities in welfare rules, the 1996 welfare reform act not only enhanced incentives for poor families to move but also (and perhaps more important) created disincentives for them to stay in "race to the bottom" states. In testing this thesis, we evaluated the mediating and moderating roles of state economic development and family structure. We merged data from three main sources: the 1996-1999 panel of the Survey of Income and Program Participation, the Urban Institute's Welfare Rules Database, and state economic data from the Bureau of Labor Statistics. Modeling both destination (pull) and departure (push) effects of welfare policy measures and selected covariates in a nested discrete-time event-history migration analysis, we found robust support for the thesis that stringency in state welfare-eligibility and behavior-related rules stimulated interstate out-migration of poor families in the United States. However poor families were not drawn to states with relatively more-lenient welfare rules, although stringency in state welfare dollar benefits inhibited in-migration and state unemployment patterns may have conditioned the migration effects of welfare-reform rules on the choice of destination. Single mothers were not more directly affected by welfare-eligibility and behavior-related rules than were poor married couples.     

French and Swedish teachers' social representations of social workers

Collaboration on children at risk is essential, but our knowledge about inter-professional collaboration between social workers and educators is limited. The aim of this study is twofold: (1) to describe French and Swedish teachers' social representation of social workers; and (2) to compare these social representations. The French sample group is composed of 77 secondary school teachers (of students from 11 to 18 years old), and the Swedish sample group is composed of 94. The method used was a ‘free association task’, commonly used to access the semantic content of social representation. Two different social representations of social workers were revealed, one for the French and one for the Swedish teachers. The French representation is characterised by highly positive aspects such as support, listening and competence. Swedish teachers' social representation of social workers is completely different: negative associations were common (44%), and among these, professional secrecy and law and regulations dominated. One plausible explanation is the difference of French and Swedish teachers' roles regarding collaboration with social workers.     

Under What Conditions do Lesbians Disclose Their Sexual Orientation to Primary Healthcare Providers? A Review of the Literature

Under what conditions do lesbians disclose their sexual orientation to primary healthcare providers? A review of the literature was undertaken to answer this question and to provide insight into the ways healthcare professionals can play an active role assisting their lesbian patients in “coming out.” Thirty empirical studies met the inclusion criteria and were reviewed. Collectively, these separate studies have found that a myriad of internal (patient attributes) and external (healthcare context, patient–provider relationship) factors influence disclosure. The discussion highlights the critical role of healthcare professionals in supporting disclosure.     

Social Cohesion and Living Conditions in the Canadian Arctic: From Theory to Measurement

Social cohesion has emerged as a powerfulhybrid concept used by academics and policyanalysts. Academics use the concept tounderline the social and economic failings ofmodernity, linking it to the decline ofcommunal values and civic participation. Policy analysts use it to highlight the socialand economic inequities caused byglobalization. The desired effect of usingthis concept is often to influence governmentsto implement policies that will enhance socialcohesion by reducing social and economicdisparities. Despite its widespread use,however, statistical measures of socialcohesion tend to overlook local, non-Westernstrategies of social inclusion as well as thesocial impact of non-Western economic systems,such as the mixed economy typical of manyAboriginal communities in North America. Inthis paper, we develop a model of socialcohesion that addresses these omissions throughthe use of social indicators that measure boththe behavior and perceptions of Inuit living inthe Canadian Arctic with respect to the social,cultural and economic conditions of Arcticcommunities. We explain how and why measuringsocial cohesion is optimized by combining bothculturally-specific and non-specific socialindicators.     

La maladie des coûts est-elle contagieuse ? Le cas des ensembles de musique ancienne

To complete traditional explanations of why the performing arts tend to run a deficit, the case of Early Music orchestras is examined. The usual mechanisms do not suffice to explain why these institutions suffer from the “illness of costs”. Two hypotheses are combined to complete Baumol’s model. For one thing the deepening deficit of Early Music orchestras is related to their professionalization; and for another, it is explained by their being simultaneously in two markets: the concert market and the musicians’ labor market, where they have to compete with subsidized orchestras.     

Equal Opportunities Policies in English Schools: Towards Greater Gender Equality in the Teaching Workforce?

The under‐representation of women in promoted posts is one particular pattern of occupational segregation by gender across post‐industrial societies. This phenomenon also characterizes those professions which have been described as ‘women‐friendly’, such as teaching. The development of national and European legislation and recommendations on equal opportunities reflects this concern to address the gender imbalance among the workforce. But do schools identify women's under‐representation in promoted posts as an issue? To what extent do school's policies recognize and remedy the gender imbalance at managerial level? To answer these questions this article draws on a study of women teachers' careers in nursery, primary and secondary education in England. It shows that school equal opportunities policy statements widely ignore the under‐representation of women in school managerial positions. It suggests that the constructions of gender issues in schools by those in charge of designing and implementing school policies, that is, head‐teachers and governors, represent a key hindering factor for equal opportunities policies to contribute to greater gender equality. A major argument in the article is that because head‐teachers' and governors' discourses do not always fundamentally challenge the position of women in society, school policies and practices can offer only a limited contribution to gender equality.     

Towards the Establishment of a Green Infrastructure in the Region of Montreal (Quebec,Canada)

Through the analysis of semi-structured interviews held with key actors involved in the planning of the Greater Montreal region, we seek to understand the conditions that could lead to the establishment of a green infrastructure for the city. This article first describes the region's environmental and political context and then analyzes the opportunities, constraints, advantages and disadvantages in the implementation of this type of project. We conclude that experts favor an approach leading to ecological connectivity, but they underline several obstacles that could hinder its implementation.     

FAMILY VALUES AND THE REGULATION OF LABOR

To be efficient, flexible labor markets require geographically mobile workers. Otherwise firms can take advantage of workers' immobility and extract rents at their expense. In cultures with strong family ties, moving away from home is costly. Thus, to limit the rents of firms and to avoid moving, individuals with strong family ties rationally choose regulated labor markets, even though regulation generates higher unemployment and lower incomes. Empirically, we find that individuals who inherit stronger family ties are less mobile, have lower wages and higher unemployment, and support more stringent labor market regulations. We find a positive association between labor market rigidities at the beginning of the 21st century and family values prevailing before World War II, and between family structures in the Middle Ages and current desire for labor market regulation. Both results suggest that labor market regulations have deep cultural roots.