The Greater Ability of Graphical Versus Numerical Displays to Increase Risk Avoidance Involves a Common Mechanism

By displaying a risk reduction of 50% graphically rather than numerically, Stone, Yates, and Parker significantly increased professed risk-avoidant behavior. The current experiments replicated this effect at various risk ratios. Specifically, participants were willing to spend more money to reduce a risk when the risk information was displayed by asterisks rather than by numbers for risk-reduction ratios ranging from 3% to 97%. Transforming the amount participants were willing to spend to logarithms significantly improved a linear fit to the data, suggesting that participants convert this variable within the decision-making process. Moreover, a log-linear model affords an exceptional fit to both the graphical and numerical data, suggesting that a graphical presentation elicits the same decision-making mechanism as does the numerical display. In addition, the data also suggest that each person removed from harm is weighted more by some additional factor in the graphical compared to the numerical presentations.     

Sample Size and Power Calculation in Comparing Diagnostic Accuracy of Biomarkers with Pooled Assessments

When testing of a biomarker is costly, pooling of samples becomes a useful and efficient alternative (Faraggi et al., 2003). In this paper, we develop procedures for sample size and power calculations for planning a study comparing the accuracy of biomarkers in diagnosis of diseases with pooled samples. Explicit formulas are derived for several important pooling strategies. The effects of pooling samples on sample size and power of the test are also discussed.     

Union Legitimacy and the Team Concept: A Case Study of Workers’ Attitudes*

Unions are facing a crisis of legitimacy resulting in part from employer‐initiated workplace participation programs that seek to undermine labor militancy and attachment to unions. The overall trend among union leaders, however, is support for the team concept when implemented in unionized settings. This study examines the effect of union involvement in the team concept on pragmatic and moral union legitimacy at the first unionized team concept assembly plant in the automobile industry—the General Motors’ truck plant in Shreveport, Louisiana. The unique contribution of the study is that it systematically examines how workers who began their careers in the industry under different production regimes view the team concept and union legitimacy. The analysis is based on a random sample survey of workers and employs an original approach of comparing work attitudes and union legitimacy among different “political cohorts.” The results indicate that the team concept threatens pragmatic union legitimacy for veteran workers because it undermines seniority rights. Significant time working under the team concept may also weaken moral union legitimacy, even among workers socialized initially in nonteam concept environments.     

Bayesian model selection for join point regression with application to age-adjusted cancer rates

Summary.  The method of Bayesian model selection for join point regression models is developed. Given a set of K +1 join point models M ₀,  M ₁, …,  M _K with 0, 1, …,  K join points respec-tively, the posterior distributions of the parameters and competing models M _k are computed by Markov chain Monte Carlo simulations. The Bayes information criterion BIC is used to select the model M _k with the smallest value of BIC as the best model. Another approach based on the Bayes factor selects the model M _k with the largest posterior probability as the best model when the prior distribution of M _k is discrete uniform. Both methods are applied to analyse the observed US cancer incidence rates for some selected cancer sites. The graphs of the join point models fitted to the data are produced by using the methods proposed and compared with the method of Kim and co-workers that is based on a series of permutation tests. The analyses show that the Bayes factor is sensitive to the prior specification of the variance σ ², and that the model which is selected by BIC fits the data as well as the model that is selected by the permutation test and has the advantage of producing the posterior distribution for the join points. The Bayesian join point model and model selection method that are presented here will be integrated in the National Cancer Institute's join point software ( http://www.srab.cancer.gov/joinpoint/ ) and will be available to the public.     

Comment: Housing Policy and Health

We summarize and comment on the policy sections of the articles in this issue concerned with the health effects of residential environments. We review the implications in the context of public policies implemented over at least the last century to improve the least, as well as most, expensive housing. We make the argument that public policy can reduce but not eliminate the contribution of housing to the differences in health between the wealthy and poor. We conclude that the applied value of work such as that presented in this issue arises from its contribution to sustaining the improvements in health enjoyed over the last century, not from whether it helps eliminate the gap in health between the poor and wealthy .     

Suicide ideation among a stratified sample of rural and urban adolescents

This study examined factors associated with sucidal ideation among a stratified sample of rural and urban adolescents. Data was collected on 1,728 eighth and tenth grade southern Nevada students from 23 schools. No overall differences were found between rural and urban adolescents, although results did indicate that grade, gender, and school achievement variations exist between rural and urban student populations. Implications for social workers and other youth service providers are discussed.     

Suicide ideation,attempts and abuse among incarcerated gang and nongang delinquents

The present study examines suicide ideation and attempts as well as reported levels of physical and sexual abuse among gang and nongang-involved incarcerated youth. The self-report survey data were collected from 334 males and 61 females who were incarcerated in Nevada youth correctional facilities in the summer of 1994. Over half (58.3 percent) of the males and nearly half (45.2 percent) of the females reported being gang members. Surprisingly high rates of abuse (more than 70 percent for both physical and sexual abuse) were found among the incarcerated females of this study. Females reported significantly more suicide attempts and were more likely to have been physically and sexually abused than males. Nongang males reported significantly more suicide attempts and were more likely to report sexual abuse than gang-involved males. Among the gang-involved delinquents, females reported significantly more suicide attempts than males. In addition, gang members who reported sexual abuse were more likely to have higher levels of suicide ideationand to have attempted suicide. Implications for youth correction specialists and social workers are discussed.The data for this study were collected under Grant #000616 from the Nevada Agricultural Experiment Station.