What to Do at Low Doses: A Bounding Approach for Economic Analysis

To quantify the health benefits of environmental policies, economists generally require estimates of the reduced probability of illness or death. For policies that reduce exposure to carcinogenic substances, these estimates traditionally have been obtained through the linear extrapolation of experimental dose-response data to low-exposure scenarios as described in the U.S. Environmental Protection Agency's Guidelines for Carcinogen Risk Assessment (1986). In response to evolving scientific knowledge, EPA proposed revisions to the guidelines in 1996. Under the proposed revisions, dose-response relationships would not be estimated for carcinogens thought to exhibit nonlinear modes of action. Such a change in cancer-risk assessment methods and outputs will likely have serious consequences for how benefit-cost analyses of policies aimed at reducing cancer risks are conducted. Any tendency for reduced quantification of effects in environmental risk assessments, such as those contemplated in the revisions to EPA's cancer-risk assessment guidelines, impedes the ability of economic analysts to respond to increasing calls for benefit-cost analysis. This article examines the implications for benefit-cost analysis of carcinogenic exposures of the proposed changes to the 1986 Guidelines and proposes an approach for bounding dose-response relationships when no biologically based models are available. In spite of the more limited quantitative information provided in a carcinogen risk assessment under the proposed revisions to the guidelines, we argue that reasonable bounds on dose-response relationships can be estimated for low-level exposures to nonlinear carcinogens. This approach yields estimates of reduced illness for use in a benefit-cost analysis while incorporating evidence of nonlinearities in the dose-response relationship. As an illustration, the bounding approach is applied to the case of chloroform exposure.     

Children and well-being: A comparison of employed and non-employed women

While employment improves health, having children at home does not. Indeed, the most likely work-family conflict for women is having children at home. In this study the effect of children on well-being was predicted to differ for employed and non-employed women. In addition, only amongst the employed women was locus of control hypothcsized to moderate this relationship. In a sample of women with partners (n = 116), using multiple-regression analysis, the results indicated that the number of children living at home, rather than the presence of young children, was associated with increased happiness in women. Employment was not predictive of women's well-being. However, it moderated the effect of number of children on their levels of happiness. In addition, non-employed women showed a U-shaped relationship between number of children and psychological distress. Finally, contrary to prediction, locus of control did not moderate the relationship between number of children and women's well-being. The findings are discussed in terms of the role expansion hypothesis.     

Pen Dudley''s name finally disappears from the public relations marquee

When the public relations firm D-A-Y was dissolved into Ogilvy & Mather Public Relations November 1, 1988, the longest lived public relations agency disappeared into the sands of time that enveloped the first four agencies started in the first decade of the waning century. The D in D-A-Y stood for Pendleton Dudley, a venerable pioneer in this vocation, who had opened his agency in Wall Street in 1909 at the urging of his good friend, Ivy Lee. Dudley, a rugged, independent product of frontier America, headed his firm for fifty-seven years—a longevity record surpassed only by that of Edward L. Bernays, who started his firm in 1919 in the Post World War I public relations boom.Pendleton Dudley—known to his close friends as Pen and to his associates in his firm as PD, was born September 8, 1876, in a small frontier town of Troy, Missouri, when America was an agricultural nation. He came to pioneer as a counselor to the corporate giants, AT&T among them, in a complex, interdependent corporate industrial America. Pen Dudley did much to infuse this field with respectability in a time when it was viewed with suspicion or disdain in its early years. He was a strong advocate of research as the only sound basis for planning and executing programs to influence public behavior. He was also active in the Public Relations Society of America after it was formed in 1948 and was in the forefront of those creating the now extinct Foundation for Public Relations Research and Education. In 1965, he received the Distinguished Service Award from the New York PRSA Chapter. He died at the age of 90 in 1966.The author is Dean Emeritus of Journalism at the University of Georgia, and co-author Effective Public Relations, 6th Ed.     

Costs and Rewards of Children: The Effects of Becoming a Parent on Adults' Lives

How do new parents differ from their childless counterparts in social and psychological resources, daily strains, and psychological well‐being? Using a nationally representative panel of 1,933 adults who were childless at the first interview, we compare 6 indicators of adults' lives for those who became parents and those remaining childless several years later, controlling for earlier states. Becoming a parent is both detrimental and rewarding. With the exception of social integration, which is greater for all groups of new parents compared with their childless counterparts, the effects of parental status on adults' lives vary markedly by gender and marital status. Unmarried parents report lower self‐efficacy and higher depression than their childless counterparts. Married mothers' lives are marked by more housework and more marital conflict but less depression than their childless counterparts. Parental status has little influence on the lives of married men.     

WHOSE GAY COMMUNITY? SOCIAL CLASS,SEXUAL SELF‐EXPRESSION,AND GAY COMMUNITY INVOLVEMENT

The visible and political gay community has been characterized as an increasingly middle-class, white institution. It is hypothesized that this middle-class nature requires economic and psychosocial resources that are not available to the working class and, thus, may limit the expression of sexual orientation for the working class. An analysis of data from the multicity Urban Men's Health Study supports this hypothesis. Nine of 14 hypothesized effects are statistically significant and indicate that working-class men who are homosexually active are less likely to describe themselves as gay, are more likely to have heterosexual experience, and are less likely to be involved in the gay community. Thus, it is important to incorporate class differences when addressing the social and the political dynamics of sexual orientation.     

Improving flexibility and efficiency by adding parallelism to genetic algorithms

In this paper we develop a study on several types of parallel genetic algorithms (PGAs). Our motivation is to bring some uniformity to the proposal, comparison, and knowledge exchange among the traditionally opposite kinds of serial and parallel GAs. We comparatively analyze the properties of steady-state, generational, and cellular genetic algorithms. Afterwards, this study is extended to consider a distributed model consisting in a ring of GA islands. The analyzed features are the time complexity, selection pressure, schema processing rates, efficacy in finding an optimum, efficiency, speedup, and resistance to scalability. Besides that, we briefly discuss how the migration policy affects the search. Also, some of the search properties of cellular GAs are investigated. The selected benchmark is a representative subset of problems containing real world difficulties. We often conclude that parallel GAs are numerically better and faster than equivalent sequential GAs. Our aim is to shed some light on the advantages and drawbacks of various sequential and parallel GAs to help researchers using them in the very diverse application fields of the evolutionary computation.     

Residual analysis for spatial point processes (with discussion)

Summary.  We define residuals for point process models fitted to spatial point pattern data, and we propose diagnostic plots based on them. The residuals apply to any point process model that has a conditional intensity; the model may exhibit spatial heterogeneity, interpoint interaction and dependence on spatial covariates. Some existing ad hoc methods for model checking (quadrat counts, scan statistic, kernel smoothed intensity and Berman's diagnostic) are recovered as special cases. Diagnostic tools are developed systematically, by using an analogy between our spatial residuals and the usual residuals for (non-spatial) generalized linear models. The conditional intensity λ plays the role of the mean response. This makes it possible to adapt existing knowledge about model validation for generalized linear models to the spatial point process context, giving recommendations for diagnostic plots. A plot of smoothed residuals against spatial location, or against a spatial covariate, is effective in diagnosing spatial trend or co-variate effects. Q – Q -plots of the residuals are effective in diagnosing interpoint interaction.     

Benchmark Analysis: Shopping with Proper Confidence

We discuss the issue of using benchmark doses for quantifying (excess) risk associated with exposure to environmental hazards. The paradigm of low-dose risk estimation in dose-response modeling is used as the primary application scenario. Emphasis is placed on making simultaneous inferences on benchmark doses when data are in the form of proportions, although the concepts translate easily to other forms of outcome data.     

Four‐Month Attentional Regulation and Its Prediction of Three‐Year Compliance

The extent to which 4‐month attentional regulation during an infant‐mother still‐face situation and 12‐month attachment security during the Strange Situation predicted rates of compliance and noncompliance during a cleanup task at 36 months was examined longitudinally in 70 infant‐mother dyads. Hierarchical multiple regression analyses indicated that infants who showed more attentional regulation during the still‐face situation with mothers later showed a higher rate of committed compliance and a lower rate of situational compliance during cleanup with mothers. Furthermore, lower levels of attentional regulation were later associated with higher rates of assertive behavior, but only for infants in an insecure attachment relationship.     

THE ANSWERING MACHINE POSES MANY QUESTIONS FOR TELEPHONE SURVEY RESEARCHERS

The proliferation of the telephone answering machine raisesa number of questions about the continued efficiency of thetelephone as a data-gathering mechanism. The most critical ofthese is what effect the use of these machines might have onestablishing contact with potential respondents. If individualsroutinely use these machines to screen calls, then their accessibilityto telephone survey researchers will be restricted. A secondquestion is the degree to which respondents who own answeringmachines and are reachable are likely to participate in a survey.A third question is the extent to which the incidence of theanswering machine as a response disposition might vary by thetime of calling and the respondent's place of residence. Thefindings of this study, based on a nationwide survey, pointto a significant proportion of answering machine owners beingreachable and willing to participate. Furthermore, the answeringmachine appears to be in use more on weekends than on weekdayevenings and in more urbanized areas than in areas with fewerinhabitants.