Misspecifications of the Normal Distribution

Incorrect statements about the normal distribution are discussed and illustrated with counterexamples.     

Gender and racial/ethnic differences in predicting adolescent sexual risk: athletic participation versus exercise

Though often conflated, informal physical exercise and organized athletic participation have very different implications for adolescent sexual risk outcomes. The purpose of this research is to disaggregate strenuous exercise from sports, examine how each is associated with sexual risk, and explain the observed differences using the conceptual lens of cultural resource theory. Using a nationally representative sample of over 16,000 public and private high school students, we employ logistic regression to test hypotheses about the gender-specific and race-specific effects of strenuous exercise and athletic participation on adolescent sexual risk behavior. The results show that both forms of physical activity buffer sexual risk for girls. Strenuous exercise is associated with increased odds of sexual risk for boys. Sports and race interact to influence boys' sexual risk outcomes: Athletic participation is associated with lowered odds of sexual risk for white male adolescents, but heightened odds of sexual risk for black male adolescents.     

Large scale communication networks—Design and analysis

The paper discusses the problem of design and analysis of large scale communication systems. An iterative process, composed of a minimum cost network design algorithm and a network performance algorithm, is presented for the solution of these problems. Computational considerations, using these algorithms, are discussed.     

Book Reviews

The diagnostic tools examined in this article are applicable to regressions estimated with panel data or cross-sectional data drawn from a population with grouped structure. The diagnostic tools considered include (a) tests for the existence of group effects under both fixed and random effects models, (b) checks for outlying groups, and (c) specification tests for comparing the fixed and random effects models. A group-specific counterpart to the studentized residual is introduced. The methods are illustrated using a hedonic housing price regression.     

Jocks, gender, race, and adolescent problem drinking

Alcohol remains the drug of choice for many adolescents; however, the nature of the relationship between athletic involvement and alcohol misuse remains ambiguous. In this article, we used a longitudinal sample of over 600 Western New York adolescents and their families to explore the gender-specific and race-specific relationships between identification with the "jock" label and adolescent alcohol consumption, specifically problem drinking. Operationalization of problem drinking included frequency measures of heavy drinking, binge drinking, and social problems related to alcohol (e.g., trouble with family, friends, school officials over drinking). Self-identified adolescent "jocks" were more likely to engage in problem drinking than their non-jock counterparts, even after controlling for gender, age, race, socioeconomic status, physical maturity, social maturity, and frequency of athletic activity. Jock identity was strongly associated with higher binge drinking frequency in Black adolescent girls. This study underscores the need to distinguish between objective and subjective meanings of athletic involvement when assessing the relationship between sport and adolescent health-risk behavior.     

Assessing the effectiveness of strategic planning

This paper describes a method for assessing the effectiveness of strategic planning systems in terms of the results actually observed subsequent to planning activity. The paper explains in particular how, in making the assessment, one might cope with the fact of environmental change subsequent to the setting of planned goals. This ends oriented approach to measuring effectiveness is shown to be complementary to process oriented approaches and is illustrated by an example from the coal industry.     

Improving homeless persons' utilisation of primary care: lessons to be learned from an outreach programme in The Netherlands

Elissen AMJ, Van Raak AJA, Derckx EWCC, Vrijhoef HJM. Improving homeless persons' utilisation of primary care: lessons to be learned from an outreach programme in The Netherlands Faced with rising homelessness, countries around the world are in need of innovative approaches to caring for those without shelter, who, more often than not, suffer from severe health problems. We conducted a case study of an innovative Dutch Primary Care for the Homeless (PCH) programme to gain insight into clients' demographic characteristics, health problems and service use, and to develop an explanation for its success in increasing the latter. Our analyses are based on a combination of quantitative and qualitative data. The results of the study suggest that the success of the PCH programme can be explained by the providers' pragmatism and will to adapt their mode of care provision to the behavioural patterns and needs of their homeless clients.     

Inflationary Expectations in Israel: A Multiple Indicators Approach

This article derives unobservable short-term inflationary expectations in Israel from their postulated effects on the velocity of demand deposits and the nominal interest rate. A multiple-indicators model is estimated to assess the impact of inflationary expectations on these variables. The expectations-formation mechanism is estimated using a multiple indicators–multiple causes (MIMIC) model. This methodology allows us to test for the structural stability of the model and estimate the relative variances of the postulated error components. Moreover, this procedure contains a built-in specification test of the chosen expectations-formation mechanism.     

The evolving role of the medical director.

A medical group, be it under one roof, as a single or multispecialty group, or in separate offices, as an independent practice association, develops with the size and make-up of its patient base. In this article we document the growth of selective contracting by third-party payers with medical groups in California and discuss the implications of these trends on the structure and management of medical practices. Specifically, we focus on the emerging role of the medical director.