Premium will continue to be on performance. Interview by Wesley Curry.

With a new name for its professional organization (the American College of Physician Executives) and a new certifying organization (the American Board of Medical Management), the profession of medical management is in the throes of significant and far-reaching change. At the College's National Conference in Washington, D.C. in May, we talked to two leaders of the profession, Michael B. Guthrie, MD, MBA, FACPE, and Robert H. Hodge, Jr., MD, FACPE about what the future holds for physician executives and what physician executives can do to position themselves for success. Dr. Guthrie, the Immediate Past President of the College is Vice President for Business Development, Penrose/St. Francis Healthcare System, Colorado Springs, Colo. Dr. Hodge, the new President of the College, is a Program Director, W.K. Kellogg Foundation, Battle Creek, Mich.     

Young Children's Prosocial and Aggressive Behaviors and Their Experiences of Being Targeted for Similar Behaviors by Peers

Children's target experiences (as recipients of prosocial peer acts and victims of peer aggression) were investigated for their concurrent and longitudinal associations with prosocial and aggressive behavior. Forty‐four children (initially 22–40 months) were observed in naturalistic interactions with peers during a two‐month period for each of three consecutive years. Results revealed no consistency over time in children's experiences as targets for aggressive or prosocial peer acts, although there was some indication that altruistic target experiences may be stable from the end of the preschool period. Early behavior appeared to affect the way children were later treated by peers, but no support was found for the idea that early target experiences influence later behavior. Prosocial behavior was concurrently and longitudinally associated with prosocial target experiences. Aggressive behavior reduced the likelihood of children being targets of prosocial peer behavior and, over time, also of their being targets of peers’ aggression.     

Pooling multivariate data under W, LR and LM tests

Two independent random samples are drawn from two multivariate normal populations with mean vectors μ1 and μ2 and a common variance-covariance matrix Σ. Ahmed and Saleh (1990) considered preliminary test maximum likelihood estimator (PMLTE) for estimating μ1 based on the Hotelling's T _N ², when it is suspected that μ1=μ2. In this paper, the PTMLE based on the Wald (W), Likelihood Ratio (LR) and Lagrangian Multiplier (LM) tests are considered. Using the quadratic risk function, the conditions of superiority of the proposed estimator for departure parameter are derived. A max-min rule for the size of the preliminary test of significance is presented. It is demonstrated that the PTMLE based on W test produces the highest minimum guaranteed efficiencies compared to UMLE among the three test procedures.     

Renyi's entropy for residual lifetime distribution

In the present paper, we introduce and study Renyi's information measure (entropy) for residual lifetime distributions. It is shown that the proposed measure uniquely determines the distribution. We present characterizations for some lifetime models. Further, we define two new classes of life distributions based on this measure. Various properties of these classes are also given.     

Modeling heteroscedastic age-period-cohort cancer data

The extent to which cancer will be a burden on the Canadian health-care system will be determined by future cancer rates and future population levels in the high-risk age groups. Parametric models of incidence and mortality rates for various cancers may be used to obtain medium-term forecasts of rates, which then can be used in conjunction with population projections to obtain forecasts of total incidence and mortality. Age-period-cohort cancer data often exhibit marked heteroscedasticity, which complicates the modeling of the data. Methods to allow for the effects of this heteroscedasticity on residual processes are developed and discussed in the context of modeling Canadian female breast-cancer incidence data.     

Peer influence and drug use among adolescents in rural areas

A sample of 1,004 eighth and tenth grade students in twenty-three small Central/East Texas communities was assessed to determine 1) their perception of the number of their friends who use drugs, 2) the amount of information they received about drugs from their friends, and 3) the connection between those perceptions and drug use. A multiple regression model which included grade, gender, the degree to which friends are perceived to use drugs and the amount of information about drugs received from friends explained 39 percent of the variance in the degree to which rural adolescents were involved in drug use. An item specific analysis of the subcomponents of these composite variables explained 44 percent of the variance in the degree to which rural adolescents were involved in drug use. This same four-factor model accurately classified over 81 percent of non-drug-users and 67 percent of users using discriminant analysis. Students who perceived a higher degree of drug use among their friends and who received more information about drugs from their friends used drugs more frequently. Lower marijuana use in these rural areas as compared to the nation, both as a peer perception and as a fact, may protect these students to a degree from broader patterns of drug use. The findings of this study support the theory that peer pressure is related to drug abuse, even in rural areas.     

Constructing the Transition to Parenthood*

How is the transition to parenthood constructed in a context in which fatherhood and motherhood are therapeutically defined? Relying on ethnographic observations of 66 expectant and new parent couples assigned to 13 different parent educator‐led groups, we show how, with the arrival of a baby, a sense of transition is crafted and often amplified. Our analysis suggests that just as the overall life course is constructed through language and meaningful gesture, so also the transition to parenthood is constructed through verbal and nonverbal signification. Using a vocabulary of contrast and change, parent edu‐cators and expectant and new parents create a collective feeling that they are witnessing a transformation of major proportions. By emphasizing the idea that things are no longer the same, parent educators also establish themselves as authorities whose job it is to steer fathers and mothers through unfamiliar terrain. For their part, expectant and new parents not only listen to but often also replicate the parent educators’ vocabularies and, in so doing, further magnify distinctions between before parenthood and after, and between one stage of parenthood and another. Childbirth stands uncomfortably at the junction of the two worlds of nature and culture. Like death and disease it is a biological event, but the defining feature of biological events in human life is their social character. Ann Oakley (1980:7)     

On-line bin packing with restricted repacking

Semi-on-line algorithms for the bin-packing problem allow, in contrast to pure on-line algorithms, the use of certain types of additional operations for each step. Examples include repacking, reordering or lookahead before packing the items. Here we define and analyze a semi-on-line algorithm where for each step at most k items can be repacked, for some positive integer k. We prove that the upper bound for the asymptotic competitive ratio of the algorithm is a decreasing function of k, which tends to 3/2 as k goes to infinity. We also establish lower bounds for this ratio and show that the gap between upper and lower bounds is relatively small.