Rejoinder to 'Ahmed, M.S. (1998). A note on regression-type estimators using multiple auxiliary information.'

In the estimators t ₃ , t ₄ , t ₅ of Mukerjee, Rao & Vijayan (1987), b _{y x} and b _{y z} are partial regression coefficients of y on x and z , respectively, based on the smaller sample. With the above interpretation of b _{y x} and b _{y z} in t ₃ , t ₄ , t ₅ , all the calculations in Mukerjee at al. (1987) are correct. In this connection, we also wish to make it explicit that b _{x z} in t ₅ is an ordinary and not a partial regression coefficient. The 'corrected' MSEs of t ₃ , t ₄ , t ₅ , as given in Ahmed (1998 Section 3) are computed assuming that our b _{y x} and b _{y z} are ordinary and not partial regression coefficients. Indeed, we had no intention of giving estimators using the corresponding ordinary regression coefficients which would lead to estimators inferior to those given by Kiregyera (1984). We accept responsibility for any notational confusion created by us and express regret to readers who have been confused by our notation. Finally, in consideration of the above, it may be noted that Tripathi & Ahmed's (1995) estimator t ₀ , quoted also in Ahmed (1998), is no better than t ₅ of Mukerjee at al. (1987).     

Distributions of the lifetimes of system components operating under an unknown common environment

SUMMARY Families of joint distributions for describing the lifetimes of a system of components that operate under an unknown environment, when the environment follows a Weibull distribution, are derived. The reliability function for this system is calculated and several properties of the aforementioned joint distributions are investigated.     

PARENTAL INFLUENCE ON GENDER AND MARITAL ROLE ATTITUDES: IMPLICATIONS FOR INTERVENTION

This study examined parental influence on specific attitudes toward marital and parental roles and nonspecific gender-role attitudes. Respondents included 173 young adults (127 women and 46 men) and their parents. Young adults' scores on the Role Orientation scale of the Marital Statisfaction Inventory and on masculinity and femininity scales from two self-report inventories (the MMPI-2 and the Personal Attributes Questionnarie) were correlated with their parents' scores on a subset of these same measures. Results indicated that (a) marital and parental role attitudes among young adults are strongly related to specific marital role attitudes of their parents but only modestly related (for women) or unrelated (for men) to nonspecific gender-role attitudes of their parents; (b) broader gender-role attitudes of young men are moderately correlated with their father's attitudes but generally uncorrelated with their mother's attitudes regarding gender roles; and (c) the relationship of young women's gender-role attitudes to both maternal and paternal attitudes is generally weaker and more complex than for young men. Clinical implications of these findings for assessment and intervention with distressed couples are discussed.     

Accommodating stochastic departures from percentile invariance in causal models

Summary.  Consider a clinical trial in which participants are randomized to a single-dose treatment or a placebo control and assume that the adherence level is accurately recorded. If the treatment is effective, then good adherers in the treatment group should do better than poor ad- herers because they received more drug; the treatment group data follow a dose–response curve. But, good adherers to the placebo often do better than poor adherers, so the observed adherence–response in the treatment group cannot be completely attributed to the treatment. Efron and Feldman proposed an adjustment to the observed adherence–response in the treatment group by using the adherence–response in the control group. It relies on a percentile invariance assumption under which each participant's adherence percentile within their assigned treatment group does not depend on the assigned group (active drug or placebo). The Efron and Feldman approach is valid under percentile invariance, but not necessarily under departures from it. We propose an analysis based on a generalization of percentile invariance that allows adherence percentiles to be stochastically permuted across treatment groups, using a broad class of stochastic permutation models. We show that approximate maximum likelihood estimates of the underlying dose–response curve perform well when the stochastic permutation process is correctly specified and are quite robust to model misspecification.     

Social Support Networks of African-American Children Attending Head Start: A Longitudinal Investigation of Structural and Supportive Network Characteristics

This study examined the stability and coherence of African‐American children's social support networks. Participants included a total of 106 3‐ to 4‐year‐old children attending Head Start centers located in the southeast. Children completed a social network interview in two consecutive years at the Head Start centers. These interviews tapped multiple dimensions of the support network including social embeddedness, proportion of the network providing support, and perceived support. Analyses focused on both the rank‐order stability of children with respect to network characteristics as well as stability of network relationships (the same individuals included in the network at both time periods). Results indicated age‐related increases in network size for adult and child categories, network size across three support domains, proportion of support scores, and perceived support from adults. In addition to age‐related changes, analyses revealed considerable rank‐order stability with respect to structural network dimensions, but very little rank‐order stability in proportion of support and perceived support scores. In contrast, both structural and supportive components of the children's networks were shown to be coherent over a one‐year period when specific network member relationships were examined. Discussion highlights both continuities and discontinuities in young children's social networks, and how data obtained in this study contribute to theory building and the systematic examination of African‐American children's emerging social networks.     

Brief admission program. An alliance of inpatient care and outpatient case management

1. Brief planned and crisis admissions to an inpatient psychiatric unit are presented as a component supportive of outpatient care and case management for chronically mentally ill patients. 2. Typical patients admitted to this inpatient short-term program are those experiencing a life stress or temporary crisis; chronically mentally ill patients who cycle and experience exacerbations of their illness; and those who need to make the transition from an acute inpatient unit to community living. 3. The Brief Admission Program treats the individual's response to and the consequences of a lifelong illness and enables the patient to return to his previous level of functioning and continue necessary outpatient treatment.     

Adaptive sampling without replacement of clusters

In a common form of adaptive cluster sampling, an initial sample of units is selected by random sampling without replacement and, whenever the observed value of the unit is sufficiently high, its neighboring units are added to the sample, with the process of adding neighbors repeated if any of the added units are also high valued. In this way, an initial selection of a high-valued unit results in the addition of the entire network of surrounding high-valued units and some low-valued “edge” units where sampling stops. Repeat selections can occur when more than one initially selected unit is in the same network or when an edge unit is shared by more than one added network. Adaptive sampling without replacement of networks avoids some of this repeat selection by sequentially selecting initial sample units only from the part of the population not already in any selected network. The design proposed in this paper carries this step further by selecting initial units only from the population, exclusive of any previously selected networks or edge units.     

The network of global corporations and elite policy groups: a structure for transnational capitalist class formation?

This study situates five top transnational policy–planning groups within the larger structure of corporate power that is constituted through interlocking directorates among the world's largest companies. Each group makes a distinct contribution towards transnational capitalist hegemony both by building consensus within the global corporate elite and by educating publics and states on the virtues of one or another variant of the neo–liberal paradigm. Analysis of corporate–policy interlocks reveals that a few dozen cosmopolitans – primarily men based in Europe and North America and actively engaged in corporate management – knit the network together via participation in transnational interlocking and/or multiple policy groups. As a structure underwriting transnational business activism, the network is highly centralized, yet from its core it extends unevenly to corporations and individuals positioned on its fringes. The policy groups pull the directorates of the world's major corporations together, and collaterally integrate the lifeworld of the global corporate elite, but they do so selectively, reproducing regional differences in participation. These findings support the claim that a well–integrated global corporate elite has formed, and that global policy groups have contributed to its formation. Whether this elite confirms the arrival of a transnational capitalist class is a matter partly of semantics and partly of substance.