Product Design for Life‐Cycle Mismatch

Life‐cycle mismatch occurs when the life cycle of a product does not coincide with the life cycles of the parts used in that product. This is particularly a problem with products that contain electronic components that sometimes have life spans of only two years. The cost of mitigating component obsolescence, which may require redesigning the product, is often considerable. Thus, prudent product design necessitates the selection of electronic components and product architecture, considering the cost of mitigating an obsolete design and other costs related to the design and manufacture of a product. Accordingly, we develop and analyze a model that shows how a product design can be effectively tailored to a particular product's life cycle.     

Bayesian D-optimal supersaturated designs

We introduce a new class of supersaturated designs using Bayesian D-optimality. The designs generated using this approach can have arbitrary sample sizes, can have any number of blocks of any size, and can incorporate categorical factors with more than two levels. In side by side diagnostic comparisons based on the E(s²)$E(s^2)$ criterion for two-level experiments having even sample size, our designs either match or out-perform the best designs published to date. The generality of the method is illustrated with quality improvement experiment with 15 runs and 20 factors in 3 blocks.     

Multivariate Parametric Spatiotemporal Models for County Level Breast Cancer Survival Data

In clustered survival settings where the clusters correspond to geographic regions, biostatisticians are increasingly turning to models with spatially distributed random effects. These models begin with spatially oriented frailty terms, but may also include further region-level terms in the parametrization of the baseline hazards or various covariate effects (as in a spatially-varying coefficients model). In this paper, we propose a multivariate conditionally autoregressive (MCAR) model as a mixing distribution for these random effects, as a way of capturing correlation across both the regions and the elements of the random effect vector for any particular region. We then extend this model to permit analysis of temporal cohort effects, where we use the term temporal cohort to mean a group of subjects all of whom were diagnosed with the disease of interest (and thus, entered the study) during the same time period (say, calendar year). We show how our spatiotemporal model may be efficiently fit in a hierarchical Bayesian framework implemented using Markov chain Monte Carlo (MCMC) computational techniques. We illustrate our approach in the context of county-level breast cancer data from 22 annual cohorts of women living in the state of Iowa, as recorded by the Surveillance, Epidemiology, and End Results (SEER) database. Hierarchical model comparison using the Deviance Information Criterion (DIC), as well as maps of the fitted county-level effects, reveal the benefit of our approach.     

Structural equation modeling of drinking motives in male DUI offenders

Measures completed by 250 men convicted of driving under the influence of alcohol (DUI) were analyzed to examine the direct effects of parental problem drinking and the mediational influence of drinking motives on alcohol use and drinking-related problem outcomes. Structural equation modeling was used to evaluate competing models in the cross-sectional data set. Results indicated that: 1) reported parental problem drinking modestly predicted both alcohol use and problem outcomes when tested in the absence of influence from drinking motives; 2) confirmatory factor analysis yielded a 4-factor drinking motives solution consisting of social, enhancement, coping with negative emotions, and interpersonal facilitation; and 3) both enhancement and interpersonal facilitation drinking motives mediated parental problem drinking's direct effect on alcohol use and problem outcomes. Drinking to cope with negative emotions, while not mediational in nature, produced a direct effect pathway to problem outcomes. The findings extend predictive utility of specific drinking motive dimensions on alcohol use and problem outcomes from previous research in community and university samples to men convicted of driving while intoxicated.     

A Second Look at Self‐employment and the Earnings of Immigrants1

Portes and Zhou (1996) present evidence to suggest that self‐employment may impact the economic fortunes of immigrant groups by generating a relatively large number of very high earners. The present analysis seeks to extend and clarify the very high earner thesis using 1990 U.S. census data. Findings across 41 immigrant samples are generally consistent with expectations. However, in the majority of cases the effect of self‐employment is due in whole or substantial part to the earnings of professional specialists. Findings are consistent with a very high earner model of nonprofessional specialist self‐employment in eleven immigrant subsamples.     

Measuring immigrant wage growth using matched CPS files

Cross-sectional estimates of immigrant wage growth have painted an optimistic picture of the ability of immigrants to adapt to the U.S. labor market: Studies using cross-sectional data have generally found the wage growth of immigrants to exceed that of the native born. This optimistic picture of immigrant economic assimilation was challenged by the important finding that compared to earlier immigrant cohorts, recent immigrants started at much lower wages. As such, the high wage growth of immigrants relative to the native born measured in cross-sectional data may simply be the spurious result of declining immigrant earnings ability. In this paper, we match Current Population Survey samples so that the wages of individual immigrant and native-born men can be followed for one year. We find that the wage growth of immigrants does exceed that of the native born. The general finding of faster immigrant wage growth also holds when imposing the foreign-born geographic distribution upon natives, but not when imposing the native-born geographic distribution on the foreign born—a result consistent with some theories of immigrant assimilation. In each comparison, however, the actual wage growth of immigrants relative to natives is similar to the predictions of cross-sectional regressions. This similarity suggests that either there is no cohort quality bias in the cross-sectional estimates of immigrant wage growth, or that there has been a coincidental increase in immigrant wage growth as the entry wages of immigrants have fallen.     

Sexual assault prevention with college-aged women: a bibliotherapy approach

The present research evaluated the efficacy of a skills-based bibliotherapy approach to sexual assault prevention for college-aged women. One hundred and ten participants were followed prospectively for 16 weeks. A self-help book, written by the authors, was compared to a wait-list control on several self-report measures. Results revealed significant differences between groups, with bibliotherapy participants reporting decreased participation in risky dating behaviors and improvement in sexual communication strategies across a variety of dating situations. However, results suggested that the self-help book was no more effective than the wait-list control in reducing rates of sexual victimization. Limitations of the study and directions for future sexual assault prevention research with women are discussed.     

Book reviews

Qualitative Sociology -     

Couples Who Live Apart: Time/Place Disjunctions And Their Consequences*

Couples who live apart present a unique opportunity to study the consequences of tampering with our culture's marital co-residence norm. Interviews with 37 spouses, representing members of 21 couples who are legally married and who live apart in service to career demands of both, suggest that time and place discontinuities result from two residence living. Two residences mean that spouses are not able to mesh and coordinate time schedules, nor do they share the common base of their co-resident counterparts. The time/place disjunctions that result threaten these marriages' ability to “make sense” to the partners of such unions. This paper examines the sense-jeopardizing consequence of living apart and suggest that this marital form's inherent strains make it a difficult lifestyle.     

BECAUSE IT'S FREE POKER! A QUALITATIVE ANALYSIS OF FREE TEXAS HOLD'EM POKER TOURNAMENTS

The game of poker has dramatically increased in popularity in America over the past decade, and includes a new trend in poker in which tournaments are played with no monetary wagering. These “free” poker tournaments are the primary focus of this project. Our interest in these free poker tournaments was twofold: first, we wished to identify what would motivate a person to play poker when there is no profit motive; second, we wanted to learn how the social dynamics of the game itself may or may not change when monetary risk is not present. Through covert participant observation of free poker tournaments at four different locations we were able to discover three main motivations among the players: sharpening skills for later cash games, sociability, and gaining the status of a “regular player.” We also discovered that the tenor and tempo of the game tended to vary not as a function of the location, but rather because of the social class of the players. We offer several hypotheses to guide future research endeavors in this area.