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981.
ALTRUISM, MATCHING, AND NONMARKET INSURANCE   总被引:1,自引:0,他引:1  
Incomplete market insurance gives rise to nonmarket arrangements for coinsurance. We find that the effort altruistically linked individuals take to avoid an accident increases with the degree of altruism. If the degree of altruism is sufficiently high, an economy with nonmarket insurance yields higher social welfare than an economy without nonmarket insurance. As altruism increases, the equilibrium level of effort approaches the second-best solution without the need for costly monitoring. Coinsurance is above (below) the socially optimal level if individuals place greater weight (less weight) on their own utility than on that of their partners.  相似文献   
982.
We investigated language development, relational aggression, and relational victimization in ethnically, socioeconomically diverse preschoolers. Relational aggression was positively related to language development. Girls were more relationally aggressive than boys, and higher‐socioeconomic status (SES) children were more relationally aggressive and victimized than lower‐SES children. Neither gender nor SES conclusively moderated the relation between language and relational aggression, though some findings suggest the possibility of stronger relations among boys and lower‐SES children. Teachers agreed on ratings of relational aggression and relational victimization to a moderate extent.  相似文献   
983.
Knowing when to compete and when to cooperate to maximize opportunities for equal access to activities and materials in groups is critical to children's social and cognitive development. The present study examined the individual (gender, social competence) and contextual factors (gender context) that may determine why some children are more successful than others. One hundred and fifty‐six children (M age=6.5 years) were divided into 39 groups of four and videotaped while engaged in a task that required them to cooperate in order to view cartoons. Children within all groups were unfamiliar to one another. Groups varied in gender composition (all girls, all boys, or mixed‐sex) and social competence (high vs. low). Group composition by gender interaction effects were found. Girls were most successful at gaining viewing time in same‐sex groups, and least successful in mixed‐sex groups. Conversely, boys were least successful in same‐sex groups and most successful in mixed‐sex groups. Similar results were also found at the group level of analysis; however, the way in which the resources were distributed differed as a function of group type. Same‐sex girl groups were inequitable but efficient whereas same‐sex boy groups were more equitable than mixed groups but inefficient compared to same‐sex girl groups. Social competence did not influence children's behavior. The findings from the present study highlight the effect of gender context on cooperation and competition and the relevance of adopting an unfamiliar peer paradigm when investigating children's social behavior.  相似文献   
984.
The rate of population growth ( u ) is an important demographic parameter used to assess the viability of a population and to develop management and conservation agendas. We examined the use of resighting data to estimate u for the snail kite population in Florida from 1997-2000. The analyses consisted of (1) a robust design approach that derives an estimate of u from estimates of population size and (2) the Pradel (1996) temporal symmetry (TSM) approach that directly estimates u using an open-population capture-recapture model. Besides resighting data, both approaches required information on the number of unmarked individuals that were sighted during the sampling periods. The point estimates of u differed between the robust design and TSM approaches, but the 95% confidence intervals overlapped substantially. We believe the differences may be the result of sparse data and do not indicate the inappropriateness of either modelling technique. We focused on the results of the robust design because this approach provided estimates for all study years. Variation among these estimates was smaller than levels of variation among ad hoc estimates based on previously reported index statistics. We recommend that u of snail kites be estimated using capture-resighting methods rather than ad hoc counts.  相似文献   
985.
Despite their conceptual importance, the effects of time preference, expected longevity, uncertainty, and risk aversion on behavior have not been analyzed empirically. We use data from the Health and Retirement Study (HRS) to assess the role of risk and time preference, expected longevity, and education on demand for three measures used for early detection of breast and cervical cancer—regular breast self-exams, mammograms, and Pap smears. We find that individuals with a higher life expectancy and lower time preference are more likely to undergo cancer screening. Less risk averse individuals tend to be more likely to undergo testing.  相似文献   
986.
This article presents an approach to the problem of terrorism risk assessment and management by adapting the framework of the risk filtering, ranking, and management method. The assessment is conducted at two levels: (1) the system level, and (2) the asset-specific level. The system-level risk assessment attempts to identify and prioritize critical infrastructures from an inventory of system assets. The definition of critical infrastructures offered by Presidential Decision Directive 63 was used to determine the set of attributes to identify critical assets--categorized according to national, regional, and local impact. An example application is demonstrated using information from the Federal Highway Administration National Bridge Inventory for the State of Virginia. Conversely, the asset-specific risk assessment performs an in-depth analysis of the threats and vulnerabilities of a specific critical infrastructure. An illustration is presented to offer some insights in risk scenario identification and prioritization, multiobjective evaluation of management options, and extreme-event analysis for critical infrastructure protection.  相似文献   
987.
988.
Objectives. The purpose of this study was to extend research on the connection between school size and student outcomes by examining how school size was related to interpersonal processes and whether the interpersonal effects of school size varied by race/ethnicity. Methods. We applied multilevel modeling techniques to a sample of 14,966 students in 84 schools from the National Longitudinal Study of Adolescent Health. Results. Increasing school size was associated with decreasing student attachment to school and to teachers as well as extracurricular participation. Student attachment and teacher bonding diminished with increasing school size at a decreasing rate (reaching minimums in schools with between 1,700–2,000 students), but extracurricular participation dropped at a steady rate. These patterns did not differ substantially by race/ethnicity. Conclusions. The size of the educational institution influences interpersonal dynamics among actors in the institution and does so similarly across student groups. More generally, this research demonstrates the importance of organizational characteristics for social life.  相似文献   
989.
We describe an approach to the assessment of parenting for families in which child abuse has been established to have occurred. Neither the category of abuse nor its physical severity adequately predicts the future wellbeing or safety of an abused child. The critical variable in determining the child's future is the level of disturbance in parenting. We argue against the most common approach to assessments of parenting, which is to generate a non‐hierarchical list of issues with the emphasis on relatively concrete and readily measurable dimensions such as social support, parental knowledge about parenting and the child's developmental status. We enhance the standard approach to assessment by organizing it around parenting capacity. We do not attempt to operationalize parenting capacity, de?ning it as the parents' ability to empathically understand and give priority to their child's needs. Adequate parenting requires that the parents be able to meet the challenges posed by their particular child's temperament and development (which may be shaped by the abusive experience) and also to accept and be prepared to address their own intrinsic characteristics which impede their parenting capacity. Parenting capacity is more dif?cult to assess than the more concrete and commonly measured aspects of parenting, but we argue that its assessment should be central to child protection management decisions. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
990.
Residents of four northern communities were surveyed about Atomic Energy of Canada Limited's proposal to site an underground repository for high-level nuclear waste somewhere in the Canadian Shield. Opposition to the repository was relatively strong in all communities, but was strongest among aboriginal respondents. Path analysis revealed that trust in nuclear regulators, faith in science and technology, and anticipated net costs were important mediators of this effect. Aboriginals were less trusting, exhibited less faith in science and technology, and perceived the costs associated with the repository to be higher than their nonaboriginal counterparts. No support was found for the hypothesis that, after controlling for aboriginal status, financially insecure individuals would display greater support for the nuclear waste repository than financially secure individuals. Policy implications for balancing perceived risks and siting needs are discussed.  相似文献   
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