Social Networks and Social Settings: Developing a Coevolutionary View

One way to think about social context is as a sample of alters. To understand individual action, therefore, it matters greatly where these alters may be coming from, and how they are connected. According to one vision, connections among alters induce local dependencies—emergent rules of social interaction that generate endogenously the observed network structure of social settings. Social selection is the decision of interest in this perspective. According to a second vision, social settings are collections of social foci—physical or symbolic locales where actors meet. Because alters are more likely to be drawn from focused sets, shared social foci are frequently considered as the main generators of network ties, and hence of setting structure. Affiliation to social foci is the decision of central interest in this second view. In this paper we show how stochastic actor–oriented models (SAOMs) originally derived for studying the dynamics of multiple networks may be adopted to represent and examine these interconnected systems of decisions (selection and affiliation) within a unified analytical framework. We illustrate the empirical value of the model in the context of a longitudinal sample of adolescent participating in the Glasgow Teenage Friends and Lifestyle Study. Social selection decisions are examined in the context of networks of friendship relations. The analysis treats musical genres as the main social foci of interest.     

The Meta Co-production of Community Outcomes: Towards a Citizens’ Capabilities Approach

This article contributes to the growing amount of literature on co-production, focusing on co-production of public outcomes and taking the perspective of local government and public managers. A model for explaining the dynamics of outcomes’ creation at the community level is provided. The core argument of the article is that community outcomes result from a sum of peer production, co-production and inter-organizational collaboration processes promoted and activated at individual, organizational and network level across the public, third and private sectors. Institutional, managerial and organizational implications are discussed. The article argues that local government and public managers are asked to play new roles and to employ a new ethos grounded in a citizens capabilities’ approach.     

Poverty in People with Disabilities: Indicators from the Capability Approach

People with disability are particularly exposed to poor living conditions: on one hand they have more difficulties in getting an income cause to their inabilities, on the other hand conditions of poverty increase the risk of disability. However, little rigorous quantitative research has been undertaken to measure the real impact of disability on poverty. Methods based on monetary set (income and consumption) may not reflect the real possibility to convert resources into the fulfilment of personal goals. The capability approach, developed by A. K. Sen, offers a useful framework for the evaluation and assessment of individual well-being considering both monetary and non-monetary resources. The study describes a methodology, derived from the capability approach, to estimate the additional income needed for various types of household with and without disabled members to ensure the same satisfaction with economic resources. The method has been applied to the Italian contest, where 2.6 million people with disability live, and then the results are compared with the findings from an analogous study conducted in UK. The study reveals that disabled people in Italy need an income level two times higher to enjoy the same level of economic satisfaction, while in UK 50% of extra resource are sufficient. The findings suggests that traditional evaluations based on consumption lead to an underestimation of the needs of household containing disabled members. It follows that the financial benefits envisaged by actions planned by government through current instruments may not be completely effective.     

Reduced Risk-Taking After Prior Losses in Pathological Gamblers Under Treatment and Healthy Control Group but not in Problem Gamblers

A group of pathological gamblers and a group of problem gamblers (i.e., gamblers at risk of becoming pathological) were compared to healthy controls on their risk-taking propensity after prior losses. Each participant played both the Balloon Analogue Risk Taking task (BART) and a modified version of the same task, where individuals face five repeated predetermined early losses at the onset of the game. No significant difference in risk-taking was found between groups on the standard BART task, while significant differences emerged when comparing behaviors in the two tasks: both pathological gamblers and controls reduced their risk-taking tendency after prior losses in the modified BART compared to the standard BART, whereas problem gamblers showed no reduction in risk-taking after prior losses. We interpret these results as a sign of a reduced sensitivity to negative feedback in problem gamblers which might contribute to explain their loss-chasing tendency.     

The role of education in the reconciliation between female occupation and family responsibilities at mid-life: the Italian case

This study, based on the data from the Survey of Health, Ageing and Retirement in Europe, deals with the labour market participation of mid-aged women and the reconciliation with family responsibilities. The analysis focuses on Italy, a fast ageing country with a very low female occupation rate. By performing a comparison with Sweden and France, we set three European models, different in terms of welfare system and gender roles, against each other. Women’s educational attainment is shown to be the most important factor associated with being in the labour market between 50 and 59 years old in all the countries analysed. Our findings suggest a couple-oriented approach to study women’s balancing of career and family: for married women, husbands’ education plays an ambivalent role concerning women's participation in the labour market, according to its combination with wives’ resources. The depressive effect on female employment of living close to a parent in poor health holds especially in Italy, suggesting the need to invest more on welfare policies in this country.     

A Probabilistic Methodology for the Assessment of Safety from Dropped Loads in Offshore Engineering

Pipeline damage by dropped objects from crane activities is a significant hazard for offshore platform installations. In this paper a probabilistic methodology is utilized for the estimation of the pipeline impact and rupture frequencies; this information is obtained both for the overall pipeline section exposed to the hazard and for a number of critical locations along the pipeline route. The presented algorithm has been implemented in a computer program that allows the analysis of a large number of possible drop points and pipeline target point locations. This methodology may be used in common risk analysis studies for evaluating the risk for platform personnel from dropped objects; however, the proposed technique may also be useful for other applications where engineering judgment has so far been the main driving criterion. In particular, two sample cases have been analyzed. The first one is the problem of selecting the best approaching route to a platform. By analyzing different route alternatives, a reduction of the impact frequency and therefore of the risk for the platform personnel may be achieved. The second application deals with the selection of the location for a safety valve at the riser base. The analysis may give useful information, such as the highest impact frequency location and the rupture frequencies upstream and downstream of the valve as a function of the valve position; this information, together with the transported medium inventory upstream of the valve, may give the designer a documented and justifiable rationale for selecting the best location for the valve from a safety point of view.     

Modeling healthcare costs in simultaneous presence of asymmetry,heteroscedasticity and correlation

Highly skewed outcome distributions observed across clusters are common in medical research. The aim of this paper is to understand how regression models widely used for accommodating asymmetry fit clustered data under heteroscedasticity. In a simulation study, we provide evidence on the performance of the Gamma Generalized Linear Mixed Model (GLMM) and log-Linear Mixed-Effect (LME) model under a variety of data-generating mechanisms. Two case studies from health expenditures literature, the cost of strategies after myocardial infarction randomized clinical trial on the cost of strategies after myocardial infarction and the European Pressure Ulcer Advisory Panel hospital prevalence survey of pressure ulcers, are analyzed and discussed. According to simulation results, the log-LME model for a Gamma response can lead to estimations that are biased by as much as 10% of the true value, depending on the error variance. In the Gamma GLMM, the bias never exceeds 1%, regardless of the extent of heteroscedasticity, and the confidence intervals perform as nominally stated under most conditions. The Gamma GLMM with a log link seems to be more robust to both Gamma and log-normal generating mechanisms than the log-LME model.     

Survival Trees: An Alternative Non-Parametric Multivariate Technique for Life History Analysis

In this paper an extension of tree-structured methodology to cover censored survival analysis is discussed. Tree-based methods (also called recursive partitioning) provide a useful alternative to the classical survival data analysis techniques, such as the semi-parametric model of Cox, whenever the main purpose is defining groups of individuals, either with complete or censored life history, having different survival probability, based on the values of selected covariates. The essential feature of recursive partitioning is the construction of a decision rule in the form of a binary tree. Trees generally require fewer assumptions than classical methods and handle non standard and non linear data structures efficiently. Tree-growing methods make the processes of covariate selection and grouping of categories in event history models explicit. An example concerning the analysis of time to marriage of Italian women is presented.     

A new 'biased coin design' for the sequential allocation of two treatments

Summary.  Efron's biased coin design is a well-known randomization technique that helps to neutralize selection bias in sequential clinical trials for comparing treatments, while keeping the experiment fairly balanced. Extensions of the biased coin design have been proposed by several researchers who have focused mainly on the large sample properties of their designs. We modify Efron's procedure by introducing an adjustable biased coin design, which is more flexible than his. We compare it with other existing coin designs; in terms of balance and lack of predictability, its performance for small samples appears in many cases to be an improvement with respect to the other sequential randomized allocation procedures.