Some Applications of the Rao Distance to Shrinkage Estimators

Bayesian statistics is concerned with how prior information influence inferences. This article studies this problem by comparing the value of the Rao distance between prior and posterior normal distributions. Particular cases include the linear Bayes estimator, the mixed estimator, and ridge-type estimators.     

Reliability estimation for the exponential distribution

This paper is concerned with classical statistical estimation of the reliability function for the exponential density with unknown mean failure time θ, and with a known and fixed mission time τ. The minimum variance unbiased (MVU) estimator and the maximum likelihood (ML) estimator are reviewed and their mean square errors compared for different sample sizes. These comparisons serve also to extend previous work, and reinforce further the nonexistence of a uniformly best estimator. A class of shrunken estimators is then defined, and it produces a shrunken quasi-estimator and a shrunken estimator. The mean square errors for both these estimators are compared to the mean square errors of the MVU and ML estimators, and the new estimators are found to perform very well. Unfortunately, these estimators are difficult to compute for practical applications. A second class of estimators, which is easy to compute is also developed. Its mean square error properties are compared to the other estimators, and it outperforms all the contending estimators over the high and low reliability parameter space. Since, for all the estimators, analytical mean square error comparisons are not tractable, extensive numerical analyses are done in obtaining both the exact small sample and large sample results.     

Creating a Consensus: Psychologists, the Supreme Court, and School Desegregation, 1952–1955

SPSSI psychologists' involvement in the early civil rights movement in the postwar United States was epitomized by their involvement in the case of Brown v. Board of Education. This article examines how social scientists sought to maintain the persona of objective, scientific expert when asked to prepare briefs for the U.S. Supreme Court for the Brown case. The social scientists believed that only by collapsing what they saw as an artificial distinction between objectivity and advocacy could the social scientist become a social activist. This article is based on extensive research in numerous archives, including the papers of Gordon W. Allport, Kenneth B. Clark, Stuart W. Cook, David Krech, the National Association for the Advancement of Colored People, Theodore M. Newcomb, Robert Redfield, and the Society for the Psychological Study of Social Issues.     

Broadening Career Horizons for Students in At-Risk Environments

Researchers and practitioners embarked on a collaborative venture to develop, implement, and evaluate a career intervention program for 7th grade students who were at-risk for vocational underachievement. Students participating in the Career Horizons Program demonstrated enhanced confidence in performing tasks related to investigating, selecting, and implementing a career choice. They also considered a greater number of careers and selected those that were congruent with their interests. No change was found in confidence regarding degree of self-knowledge. Suggestions are provided for improving on the development and evaluation of career exploration programs to enhance career self-efficacy and broaden the career horizons of students in at-risk environments.     

Foreign-born health integration during the transition to adulthood: The case of weight

Nativity differences in youths’ health in the United States are striking—the children of foreign-born parents often have healthier outcomes than those of native-born parents. However, very little is known about how immigrant-native differences evolve within the same individuals over time, or about life cycle aspects of the health-related integration of youth with migration backgrounds. Using data from the National Longitudinal Study of Adolescent Health, I examine nativity differences in trajectories of weight gain during adolescence and early adulthood, as well as the degree to which temporal patterns are stratified by race/ethnicity and socioeconomic status. I examine whether nativity differences converge, diverge or remain stable over time, and whether patterns are socially stratified within and across nativity groups. I find that first-generation adolescents begin at a lower weight than their third generation peers and gain weight at a significantly slower pace, resulting in meaningful differences by early adulthood. More complex examination of the relationship between nativity and weight gain reveals additional differences by ethnicity: the foreign-born advantage over time does not extend as strongly to Hispanic adolescents. The findings demonstrate how the health-related integration of foreign-born youth is tied to race/ethnicity and socioeconomic circumstances, and suggest the need to examine the ways in which social circumstances and health change together.     

Home birth and the National Australian Maternity Services Review: too hot to handle?

Background

In February 2009 the Improving Maternity Services in Australia – The Report of the Maternity Services Review (MSR) was released, with the personal stories of women making up 407 of the more than 900 submissions received. A significant proportion (53%) of the women were said to have had personal experience with homebirth. Little information is provided on what was said about homebirth in these submissions and the decision by the MSR not to include homebirth in the funding and insurance reforms being proposed is at odds with the apparent demand for this option of care.

Method

Data for this study comprised 832 submissions to the MSR that are publicly available on the Commonwealth of Australia Department of Health and Aging website. All 832 submissions were downloaded, coded and then entered into NVivo. Content analysis was used to analyse the data that related to homebirth.

Findings

450 of the submissions were from consumers of maternity services (54%). Four hundred and seventy (60%) of the submissions mentioned homebirth. Overall there were 715 references to home birth in the submissions. The submissions mentioning homebirth most commonly discussed the ‘Benefits’ and ‘Barriers’ in accessing this option of care. Benefits to the baby, mother and family were described, along with the benefits obtained from having a midwife at the birth, receiving continuity of care and having a good birth experience. Barriers were described as not having access to a midwife, no funding, no insurance and lack of clinical privileging for midwives.

Conclusion

Many positive recommendations have come from the MSR, however the decision to exclude homebirth from these reforms is perplexing considering the large number of submissions describing the benefits of and barriers to homebirth in Australia. A concerning number of submissions discuss having had or having considered an unattended birth at home due to these barriers. Overall there is the belief that not enabling access to funded, insured homebirth in Australia is a violation of human rights. It appears that homebirth was considered by the MSR as ‘too hot to handle’ and by dismissing it as a minority issue the government sought to avoided dealing with homebirth as a ‘sensitive and controversial issue.’