Properties of Added Variable Plots in Cox's Regression Model

The added variable plot is useful for examining the effect of a covariate in regression models. The plot provides information regarding the inclusion of a covariate, and is useful in identifying influential observations on the parameter estimates. Hall et al. (1996) proposed a plot for Cox's proportional hazards model derived by regarding the Cox model as a generalized linear model. This paper proves and discusses properties of this plot. These properties make the plot a valuable tool in model evaluation. Quantities considered include parameter estimates, residuals, leverage, case influence measures and correspondence to previously proposed residuals and diagnostics.     

Family structure,residential mobility,and school dropout: A research note

This paper examines the hypothesis that high levels of residential mobility among nonintact families account for part of the well-known association between living in a nonintact family and dropping out of high school. Children from single-parent families and stepfamilies are more likely than children from two-parent families to move during the school year. As much as 30% of the difference in the risk of dropping out between children from stepfamilies and children from intact families can be explained by differences in residential mobility. Previously, mechanisms explaining school failure on the part of children in nonintact families were more plausible for children in single-parent families than for children in stepfamilies; high levels of residential mobility apply to both groups of children. In addition, residential mobility lends itself to manipulation by public policy, with potentially remedial effects for vulnerable children. Earlier versions of this paper were presented at the 1990 meetings of the American Sociological Association, held in Washington DC, and at the 1991 meetings of the Eastern Sociological Society held in Providence. We are grateful to Andrew Cherlin, Melvin Kohn, Gary Sandefur, and several anonymous referees for their valuable comments, to Robert Davis for his computational assistance, and to Tobey H. Sohn and Teresa A. Withers for secretarial help. Support to the senior author was provided by the National Institute on Aging under Grant HD 19375-03 and by the W.T. Grant Faculty Scholars Award. Support for computing facilities was provided by a grant to the Hopkins Population Center (PD30 H006268-19). 1994 Population Association of America     

Changes in the earnings of Arab men in the US between 2000 and 2002

Using public-use microdata samples from the American Community Survey, we find that Middle Eastern Arab men and Afghan, Iranian, and Pakistani men experienced a significant earnings decline relative to non-Hispanic whites between 2000 and 2002. Further analyses based on the Juhn–Murphy–Pierce wage decomposition technique as well as quantile regression indicate that this earnings decline is not explained by changes in the structure of wages or in observable characteristics beyond ethnicity. Our interpretation is that the unanticipated events of September 11th, 2001 negatively affected the labor-market income of the groups most closely associated with the ethnicity of the terrorists.

Breakdown of teenage placements in Swedish foster and residential care

This article deals with the problem of breakdown in different types of out‐of‐home care (foster care/residential care) for Swedish teenagers. How often are such placements prematurely terminated against the wishes and intentions of child welfare authorities? Which factors appear to increase or decrease the risk of placement breakdown? The sample consists of a national cohort of 776 youths who started 922 placements during 1991. Every placement was followed in municipal case files for a maximum period of five years. Between 30 and 37% of all placements were prematurely terminated, the exact figure depending on whether a narrow or wide definition of breakdown was applied. The lowest rates of breakdown were found in kinship care and secure units, the highest in non‐kinship foster homes. Teenagers who display antisocial behaviour and/or have mental health problems constitute a high‐risk category for most types of out‐of‐home care, but especially in non‐kinship foster homes. Risk factors in relation to breakdown were analysed in the four main forms of Swedish out‐of‐home care separately (foster homes, privately/publicly run residential care and secure units). The analysis pointed out that risk factors are not the same in all types of care, but antisocial behaviour at time of placement increased the risk in most forms of care. Prior research indicates that placement breakdown is a major problem of child welfare in other countries, and this study found that Sweden is no exception.     

Assessing families and other client systems in community-based programmes: development of the CALF

Programmes providing services to children and families often face the challenge of assessing not only the child referred, but also the child’s family system and its individual members. Recognizing that household/family members can cause, contribute to or affect a child’s problems requires that human service agencies utilize assessment tools capable of assessing family members across the lifespan. The literature references many assessment tools used by clinical programmes in mental‐health settings that are not well suited to use in social service agencies with multidisciplinary staff at different skill levels. As a response to this dilemma, the authors have developed the Collaborative Assessment of Life Functioning (CALF), a user‐friendly tool that assesses various areas of life functioning. Based on Maslow’s motivation theory, person‐in‐environment and systems theories, the CALF can be used with various client systems. This paper describes the development of the tool, its purpose and use, the importance of assessment tools in the helping process and considerations for agencies wishing to use an assessment tool like the CALF. The authors also discuss the applicability of the CALF in human services and social service agency settings and with diverse client populations.     

Roads and Diversification of Activities in Rural Areas: A Cameroon Case Study

This article uses the 2001 Cameroon National Household Survey (ECAM II) to analyse how road access affects labour activities. It shows that one‐size‐fits‐all road investments are irrelevant because the effects of roads are neither systematic nor uniform: the impacts of isolation on household well‐being through labour‐market opportunities are heterogeneous and depend on local characteristics. In view of the diversification of activities in household strategy, it finds that better road access increases the number of activities within those households that are most isolated.     

Towards Common Ground and Trading Zones in Management Research and Practice

The purpose and nature of management scholarship is contested, evidenced by debates about the ‘academic–practitioner divide’ and attendant remedies for addressing it, including mode 2 and mode 3 research, engaged scholarship, evidence‐based management and design science. In this paper the authors argue that, without a culture of dialogical encounter, management scholarship will never be able to emerge from its adolescence, and management will not develop into the profession that it should and can become. The central proposition is that the highly fragmented landscape of management (practice and scholarship) lacks sufficient capability for dialogue among the plurality of actors situated across that landscape. Developing the dialogical capability ultimately required to break this fundamental impasse demands, first, a shared sense of purpose and responsibility (akin to the Hippocratic Oath in medicine) and, second, institutional entrepreneurship to establish more and better ‘trading zones’. Drawing on the philosophy of pragmatism, the authors further this endeavour by identifying and proposing key elements of a statement of shared purpose and responsibility. Finally, they explore the nature and characteristics of successful trading zones, highlighting particular examples that have already been created in management studies.