Collective risk aversion

In this article we analyze the risk attitude of a group of heterogeneous agents and we develop a theory of comparative collective risk tolerance. In particular, we characterize how shifts in the distribution of individual levels of risk tolerance affect the group’s attitude towards risk. In a model with efficient risk-sharing and two agents an increase in the level of risk tolerance of one or of both agents might have an ambiguous impact on the collective level of risk tolerance; the latter increases for some levels of aggregate wealth while it decreases for other levels of aggregate wealth. For more general populations we characterize the effect of first-order like shifts (individual levels of risk tolerance more concentrated on high values) and second-order like shifts (more dispersion on individual levels of risk tolerance) on the collective level of risk tolerance. We also evaluate how shifts in the distribution of individual levels of risk tolerance impact the collective level of risk tolerance in a framework with exogenous egalitarian sharing rules. Our results permit to better characterize differences in risk taking behavior between groups and individuals and among groups with different distributions of risk preferences.     

Nutrient intake in day workers and shift workers

Abstract

The 24-h dietary intake, nutritional status parameters and psychosomatic factors of two-shift, three-shift and day workers were compared. Estimations of the dietary intake (across a work cycle) were made by use of a nutrient database. No significant differences were found between the groups for a large number of nutritional variables: intake of energy; intake and percentage of energy from protein, fat, total carbohydrates and sucrose; intake of coffee; and intake and density of vitamins and minerals. Only minor differences were found between the groups with regard to the quantitative intake of alcohol and calcium, and with regard to the quality of the diet (percentage of energy from alcohol, density of calcium). The groups differed significantly with respect to attitude towards work hours (three-shift workers being most negative in their attitude) and sleep disturbances (shift workers being most negative). The three-shift workers were more evening-oriented and they had higher concentrations of glucose in their blood. It was concluded that work hours not related to nutritional intake—at least not when total amounts across time are considered. It was also concluded that work hours were not related to Body Mass Index or blood lipids: triglycerides, total cholesterol, LDL (low-density lipoprotein) cholesterol and HDL (high-density lipoprotein) cholesterol.     

Children’s Experiences of Completing a Computer‐Based Violence Survey: Ethical Implications

This article aims to contribute to the discussion about the ethics of research on children when studying sensitive issues such as violence. The empirical analysis is based on the accounts given by children (11 377) who completed a computer‐based questionnaire about their experiences of violence (‘The Finnish Child Victim Survey 2008’) and their reflections on the survey. We argue that experiences of violence should not be excluded from the research agenda on children due to ethical reasons, but that a more sophisticated practice should be developed instead to meet the needs and rights of children as informants. © 2010 The Author(s). Journal compilation 2010 National Children’s Bureau and Blackwell Publishing Limited.     

Child custody issues and co‐occurrence of intimate partner violence and child maltreatment: controversies and points of agreement amongst practitioners

The situation of families undergoing separation in a context of co‐occurrence of intimate partner violence (IPV) and child maltreatment raises certain issues related to child custody. The results presented in this paper were collected and analysed within the framework of a qualitative study aiming to identify the principal points of agreement and the main controversies amongst practitioners in several different types of organizations. Focus groups were held with a total of 43 practitioners from six different settings concerned with child custody in cases of co‐occurrence of IPV and child maltreatment. Although they agreed on the importance of ensuring the safety of victims of violence, their views diverged on three points: (1) the importance of preserving the father–child relationship; (2) collaboration between voluntary organizations and semi‐voluntary or legal agencies; and (3) consideration of cultural differences.     

Time series count data regression

The count data model studied in the paper extends the Poisson model by al-lowing for overdispersion and serial correlation. Alternative approaches to esti-mate nuisance parameters, required for the correction of the Poisson maximum likelihood covariance matrix estimator and for a quasi-likelihood estimator, are studied. The estimators are evaluated by finite sample Monte Carlo experi-mentation. It is found that the Poisson maximum likelihood estimator with corrected covariance matrix estimators provide reliable inferences for longer time series. Overdispersion test statistics are wellbehaved, while conventional portmanteau statistics for white noise have too large sizes. Two empirical illustrations are included.     

Pan-European groupings: A case study in paint manufacture

This complete Case Study, including Teaching Notes, won the 1991 EFMD Case Writing Competition Prize on a European theme, as well as receiving much praise from the judges. The Case concerns a group of four different European paint manufacturers co-operating in an EC Economic Interest Grouping to improve their economic position in European markets. The co-ordination of raw material purchasing policies was the first area of joint action; they obtained significant discounts straight away. Then they could begin to think about competing together against the big paint multinationals established in Europe. Later, talks started on joint investment and technology transfer.Lluis Renart and Francesco Parés have written a stimulating Case Study with Teaching Notes of value to business students and managers wishing to test out their analytical abilities.     

Analysis of individual- and time-specific covariate effects on survival of Serinus serinus in north-eastern Spain

We developed models for the analysis of recapture data for 2678 serins ( Serinus serinus ) ringed in north-eastern Spain since 1985. We investigated several time- and individual-specific factors as potential predictors of overall mortality and dispersal patterns, and of gender and age differences in these patterns. Time-specific covariates included minimum daily temperature, days below freezing, and abundance of a strong competitor, siskins ( Carduelis spinus ) during winter, and maximum temperature and rainfall during summer. Individual covariates included body mass (i.e. body condition), and wing length (i.e. flying ability), and interactions between body mass and environmental factors. We found little support of a predictive relationship between environmental factors and survival, but good evidence of relationships between body mass and survival, especially for juveniles. Juvenile survival appears to vary in a curvilinear manner with increasing mass, suggesting that there may exist an optimal mass beyond which increases are detrimental. The mass-survival relationship does seem to be influenced by at least one environmental factor, namely the abundance of wintering siskins. When siskins are abundant, increases in body mass appear to relate strongly to increasing survival. When siskin numbers are average or low the relationship is largely reversed, suggesting that the presence of strong competition mitigates the otherwise largely negative aspects of greater body mass. Wing length in juveniles also appears to be related positively to survival, perhaps largely due to the influence of a few unusually large juveniles with adult-like survival. Further work is needed to test these relationships, ideally under experimentation.     

Women’s Employment Status,Coercive Control,and Intimate Partner Violence in Mexico

Findings from previous studies examining the relation between women’s employment and the risk of intimate partner violence have been mixed. Some studies find greater violence toward women who are employed, whereas others find the opposite relation or no relation at all. I propose a new framework in which a woman’s employment status and her risk of violent victimization are both influenced by the level of control exercised by her partner. Controlling men will actively prevent women from working and are also more likely to physically harm their partners. Using a statistical model in which the effect of omitted characteristics on women’s employment and their risk of violence are allowed to be correlated reverses the estimated association between employment and violence. The final results show that employment reduces women’s risk of violence. Data for the study are drawn from a sample of over 30,000 Mexican women in intimate relationships. The findings have broad implications given the increase in female labor force participation in many parts of the world.