Sex education for children in a residential center.

Sex education programs for emotionally disturbed children present special problems. This article emphasizes training of child care workers and their role as teachers.     

Adolescent Risk Behavior Patterns: Effects of Structured Time-Use,Interpersonal Connections,Self-System Characteristics,and Socio-Demographic Influences

The relationships between risk behaviors and factors representing multiple ecological layers are examined among a sample of youth in grades seven through 12 (n = 2,701). Our primary interest is in the relationship between structured time-use as a protective factor and youth risk behavior patterns. Two other layers of protective factors are also examined, those dealing with interpersonal connections and with self-system characteristics. Concomitant demographic factors in the study are age, ethnicity, gender, and socioeconomic status. Stepwise multiple regression analysis reveals that less risk behavior is associated with greater attachment to school, greater school success, closer relationships with parents, and greater participation in structured time-use; significant predictors of more risk behavior are being older, being male, and having one good friend. Implications for professional practice include employing a comprehensive, ecological approach to prevention and intervention, and enacting social support initiatives at multiple levels.     

Variation in height acceleration in the Fels growth data

The Fels growth data record at half-yearly intervals the heights of children from birth to adulthood, and are the basis for pediatricians' growth charts used throughout North America. Aspects of human growth are the subject of a large medical and statistical literature. This paper uses smoothing splines to study the variation in height acceleration. By use of a functional version of principal-components analysis, we find that variation in the acceleration curve is essentially three-dimensional in nature. Evidence for a small growth spurt between the ages of six and eight, reported for data collected in Switzerland, is examined, and little support is found for the existence of this phenomenon in the Fels data.     

Trajectories of functional impairment in later life.

Functional impairment trajectories in late adulthood over a decade are characterized using the Longitudinal Retirement History Study (LRHS) data set. Non-linear patterns of age-related increase in impairment are documented with longitudinal data. Subsets of panelists from the initial large, nationally representative probability sample of employed males and unmarried employed females (N = 11,000) also exhibit differential non-linear trajectories of impairment by sex, income, and educational attainment. Concurrent analysis of the relationship over a decade among sex, SES, and functional impairment suggests that in health research, both sex and SES are broad proxy variables whose usefulness for understanding health outcomes and for policy analysis would be enhanced by the specification of components.     

Efficient construction of reversible jump Markov chain Monte Carlo proposal distributions

Summary. The major implementational problem for reversible jump Markov chain Monte Carlo methods is that there is commonly no natural way to choose jump proposals since there is no Euclidean structure in the parameter space to guide our choice. We consider mechanisms for guiding the choice of proposal. The first group of methods is based on an analysis of acceptance probabilities for jumps. Essentially, these methods involve a Taylor series expansion of the acceptance probability around certain canonical jumps and turn out to have close connections to Langevin algorithms. The second group of methods generalizes the reversible jump algorithm by using the so-called saturated space approach. These allow the chain to retain some degree of memory so that, when proposing to move from a smaller to a larger model, information is borrowed from the last time that the reverse move was performed. The main motivation for this paper is that, in complex problems, the probability that the Markov chain moves between such spaces may be prohibitively small, as the probability mass can be very thinly spread across the space. Therefore, finding reasonable jump proposals becomes extremely important. We illustrate the procedure by using several examples of reversible jump Markov chain Monte Carlo applications including the analysis of autoregressive time series, graphical Gaussian modelling and mixture modelling.     

RULES OR POLITICS?: AN EMPIRICAL ANALYSIS OF ITC ANTI-DUMPING DECISIONS

This research analyzes the International Trade Commission's anti-dumping decisions from 1980 to 1986. The results suggest that commissioners use criteria consistent with the instructions set forth in U.S. legislation. The analysis also indicates that political variables help predict commissioner decisions. Petitions involving Senate oversight committee members' constituencies may be systematically favored in the process. Evidence of possible bias toward less-developed-country exports is presented as well. The methodology also yields estimates of commissioner-specific fixed effects.     

Compensation,employment, and the political activity of public employee unions

It has been hypothesized that because public employee unions are politically influential, they have a bargaining advanatage over their private-sector counterparts. Previous studies, however, have not directly measured the political activities of public employee unions and have instead usually used some type of unionization proxy. This paper uses unpublished data from the International City Managers Association to develop a more direct measure of union political activity. Using this measure, it is found that an increase in union political activity leads to higher compensation and employment for public employee union members.