Heteroscedastic Global Tests that the Regression Parameters for Two or More Independent Groups are Identical

Simulation results are reported on methods that allow both within group and between group heteroscedasticity when testing the hypothesis that independent groups have identical regression parameters. The methods are based on a combination of extant techniques, but their finite-sample properties have not been studied. Included are results on the impact of removing all leverage points or just bad leverage points. The method used to identify leverage points can be important and can improve control over the Type I error probability. Results are illustrated using data from the Well Elderly II study.     

Spatial variation in soil inorganic nitrogen across an arid urban ecosystem

We explored variations in inorganic soil nitrogen (N) concentrations across metropolitan Phoenix, Arizona, and the surrounding desert using a probability-based synoptic survey. Data were examined using spatial statistics on the entire region, as well as for the desert and urban sites separately. Concentrations of both NO₃-N and NH₄-N were markedly higher and more heterogeneous amongst urban compared to desert soils. Regional variation in soil NO₃-N concentration was best explained by latitude, land use history, population density, along with percent cover of impervious surfaces and lawn, whereas soil NH₄-N concentrations were related to only latitude and population density. Within the urban area, patterns in both soil NO₃-N and NH₄-N were best predicted by elevation, population density and type of irrigation in the surrounding neighborhood. Spatial autocorrelation of soil NO₃-N concentrations explained 49% of variation among desert sites but was absent between urban sites. We suggest that inorganic soil N concentrations are controlled by a number of ‘local’ or ‘neighborhood’ human-related drivers in the city, rather than factors related to an urban-rural gradient.     

How Welfare Policies Affect Adolescents' School Outcomes: A Synthesis of Evidence From Experimental Studies

Using data from 8 random assignment studies and employing meta‐analytic techniques, this article provides systematic evidence that welfare and work policies targeted at low‐income parents have small adverse effects on some school outcomes among adolescents ages 12 to 18 years at follow‐up. These adverse effects were observed mostly for school performance outcomes and occurred in programs that required mothers to work or participate in employment‐related activities and those that encouraged mothers to work voluntarily. The most pronounced negative effects on school outcomes occurred for the group of adolescents who had a younger sibling, possibly because of the increased home and sibling care responsibilities they assumed as their mothers increased their employment.     

The Market Provision of Management Services, Information Asymmetries and Service Quality—Some Market Solutions: an Empirical Example

This article examines the problems of information asymmetry associated with the market provision of managerial services. Such problems are heightened by those characteristics which differentiate services from goods. Two unique, and central, characteristics of services, are intangibility and perishability. These create special problems for the market provision of services. In particular they make for difficulties in assessing quality; whereas the producer may know product quality, the buyer often does not. The asymmetry between sellers and buyers is of two types: Adverse selection and moral hazard. Adverse selection occurs when the buyer cannot observe the relevant characteristics of the seller or the conditions under which they work. The problem of moral hazard is the buyer's inability to observe the action taken by the sellers. If these difficulties are not overcome, the market could collapse as companies withdraw and internalize service provision. However, each market has a number of in-built mechanisms which remedy the harmful effects associated with information-related problems. The institutional arrangements which predominate in particular markets are dependent upon the trust-producing mechanisms within those markets. Consequently, market responses to information asymmetries are far from uniform. The argument is illustrated using the example of the executive recruitment industry. In this respect the paper is a highly focused study of those mechanisms which overcome information asymmetries in one service market.     

Factors Affecting Children’s Adjustment to the Death of a Parent: The Social Work Professional’s Viewpoint

This study investigated factors affecting the adjustment of parentally bereaved children by reviewing existing literature and comparing it to observations made by professional social workers. Interviewees had between 1 1/2 and 22 years of experience in counseling bereaved children. The specific factors examined were age and sex of the bereaved child, circumstances of the death, and adjustment of remaining caregiver. Participants (n = 5) responded to an interview instrument specifically designed for this study which contained seven in-depth, open-ended questions. Participants’ replies were mostly in accordance with the literature, but also generated some new perspectives that had not been previously considered for this study and had not appeared in the literature. This study has implications for practice with parentally bereaved children and their surviving caregivers.Rebecca M. Hope, LCSW, Outpatient Clinician, New River Valley Community Services, 700 University City Boulevard, Blacksburg, VA 24060.Diane M. Hodge, Ph.D. is an Associate Professor of Social Work, Radford University, P.O. Box 6958, Radford, VA 24141; e-mail: dmhodge@radford.eduAddress correspondence to Rebecca M. Hope, LCSW, Outpatient Clinician, New River Valley Community Services, 700 University City Boulevard, Blacksburg, VA 24060; e-mail: rmhope@verizon.net     

Pulling together: building a community debriefing team.

1. Research shows that many emergency workers are affected physically and emotionally by critical incident stress. 2. Debriefings conducted by trained team members are an effective method to mitigate the impact of critical incident stress. A debriefing is a structured, time-limited group intervention. 3. Cooperation among community agencies is essential for the development and effective functioning of a critical incident stress debriefing team. 4. Several teams in Illinois have organized to form a Critical Incident Stress Debriefing Network. The Illinois network is part of an international organization composed of critical incident stress debriefing providers.     

Intergenerational and career mobility in Britain: An integrated analysis

Mobility analysis has traditionally concentrated on the task of charting flows in the two-way contingency table which relates occupational origin to occupational destination. It has not yet undertaken a unified analysis of intergenerational and intragenerational aspects of mobility. And only rarely does it incorporate terms which represent ordered concepts such as inequality or vertical movement. In contrast, path analysis has typically imposed strong orderings on the data, and it has been employed to tease out the relations among several occupational variables. Its main defect is that it entirely abstracts from shifts in mean occupational position, and also from change in the shape of the occupational distribution. Yet both of these are important sources of mobility. The present paper shows how two innovations in mobility analysis may be generalized to constitute a technique which unites the strengths of path analysis with those of log-linear analysis. The two innovations are (a) the conceptual disaggregation of perfect and exchange mobility, and (b) the imposition of an ordered component within each (K. Hope, 1981, Sociology 15, 19–55). The outcome of this generalization is a simple yet powerful account of mobility in Britain.