IN JUSTIFICATION OF WALD'S CRITERION OF EFFICIENCY OF EXPERIMENTAL DESIGNS IN RELATION TO THE WEIGHING PROBLEM1

Wald (1943), among others, examined the question of efficiency of experimental designs in general and suggested the criterion of maximization of the det. [X'X] for the purpose, where X denotes the design matrix. In the same context, Ehrenfeld (1955) recommended the maximization of the minimum eigenvalue of [X'X] as the desideratum. It has been shown in this note that for weighing designs in general maximization of det. [X'X] may be preferred to the latter criterion.     

Genetically Modified Organisms and the U.S. Retail Food Labeling Controversy: Consumer Perceptions,Regulation, and Public Policy

In this article, we address the public issue of mandatory Genetically Modified Organism (GMO) retail food labeling in the U.S., first by reviewing the policy arguments both in support and against labeling food containing GMOs; second, by describing the existing U.S. federal regulatory system pertaining to GMO labeling, and why it does not presently require labeling of food containing GMOs; third, by reviewing and interpreting the results of studies of American consumer attitudes toward mandatory GMO retail food labeling; fourth, by evaluating, through the utilization of issue life cycle analysis in the nonmarket environment, where the issue of GMO retail food labeling stands in the national public policy process; fifth, summarizing the state of scientific evidence addressing the safety of GMO foods and the existing regulatory and public policy environment for this issue; and sixth, offering legislative and litigation strategies for the mainstream food nonmarket strategy framework to formally assess the GMO industry to protect their interests and those of American consumers not concerned with GMO food ingredients, while offering a voluntary labeling strategy for firms responding to and recognizing the “rights” of American consumers who “choose” to purchase non‐GMO food products.     

Differences in Retail Inventory Investment Behavior During Macroeconomic Shocks: Role of Service Level

In this article, we analyze how retailers change their inventory investment behavior in response to macroeconomic shocks. We examine if service level, as measured by the ratio of stockout to inventory holding costs, can explain the differences in observed behavior across retailers. We use data on macroeconomic indicators and quarterly filings of US public retailers from 1985 to 2009 to estimate a dynamic model of short‐ and long‐term impact of macroeconomic shocks on inventory investment. Our results show that retailers with a high service level increase their inventory investment significantly more than those with a low service level during expansion shocks. Conversely, retailers with a low service level curtail their inventory investment significantly more than those with a high service level during periods of economic contractions. Thus, we show that the aggregate change in inventory investment documented in prior macroeconomics research is driven by different sets of retailers, as predicted by newsvendor logic. We draw implications of our findings to retailers as well as their suppliers.     

Creating elder-friendly communities: preparations for an aging society

Because many communities where older people live were not designed for their needs, older residents may require support to remain in the least restrictive environment. "Age-prepared communities" utilize community planning and advocacy to foster aging in place. "Elder-friendly communities" are places that actively involve, value, and support older adults, both active and frail, with infrastructure and services that effectively accommodate their changing needs. This paper presents an analysis of the literature and results of a Delphi study identifying the most important characteristics of an elder-friendly community: accessible and affordable transportation, housing, health care, safety, and community involvement opportunities. We also highlight innovative programs and identify how social workers can be instrumental in developing elder-friendly communities.     

Bayesian analysis of competing risks with partially masked cause of failure

Summary. Bayesian analysis of system failure data from engineering applications under a competing risks framework is considered when the cause of failure may not have been exactly identified but has only been narrowed down to a subset of all potential risks. In statistical literature, such data are termed masked failure data. In addition to masking, failure times could be right censored owing to the removal of prototypes at a prespecified time or could be interval censored in the case of periodically acquired readings. In this setting, a general Bayesian formulation is investigated that includes most commonly used parametric lifetime distributions and that is sufficiently flexible to handle complex forms of censoring. The methodology is illustrated in two engineering applications with a special focus on model comparison issues.     

Indoor tanning and problem behavior

OBJECTIVE: The authors examined factors predicting college students' use of tanning beds. PARTICIPANTS AND METHODS: Undergraduate students (N = 745) at a large Northeastern university participated in the study by answering a survey measuring tanning behavior and other psychosocial variables, including sensation seeking, self-esteem, tanning image beliefs, and friends' tanning bed use. RESULTS: All 3 systems from problem behavior theory predicted past tanning bed use and intention to use tanning beds. The authors observed a positive association between sensation seeking and intention to use tanning beds. Tanning image beliefs were positively associated with both past tanning behavior and intention to use tanning beds. CONCLUSIONS: Interventions focusing on friend and acquaintance social network influences may be more effective than health-risk campaigns in reducing tanning bed use.     

Confidence Interval of the Difference of Two Independent Binomial Proportions Using Weighted Profile Likelihood

Interval estimation of the difference of two independent binomial proportions is an important problem in many applied settings. Newcombe (1998 Newcombe , R. G. ( 1998 ). Interval estimation for the difference between independent proportions: comparison of seven methods . Statistics in Medicine 17 : 873 – 890 .[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) compared the performance of several existing asymptotic methods, and based on the results obtained, recommended a method known as Wilson's method, a modified version of a method originally proposed for single binomial proportion. In this article, we propose a method based on profile likelihood, where the likelihood is weighted by noninformative Jeffrey' prior. By doing extensive simulations, we find that the proposed method performs well compared to Wilson's method. A SAS/IML program implementing this method is also given with this article.     

Unionization and Income Growth of Racial Minority Immigrants in Canada: A Longitudinal Study

This study examines the effect of unionization on the labor market integration of newly arrived immigrants in Canada. We find that non‐white recent immigrants gain access to unionized jobs at a slower rate than do white recent immigrants. The effect of unionization on earnings is somewhat lower for non‐white recent immigrants than for white recent immigrants. These findings are based on growth curve modeling of longitudinal data from the Survey of Labour and Income Dynamics (SLID). Therefore, unionization does not contribute to reducing the earnings gap of non‐white recent immigrants relative to white immigrants and the native‐born.