Exchange curves for fixing batch quantities

The problem considered is that of choosing batch quantities to minimize costs, subject to the constraints that neither overall set-up costs nor overall set-up time can be increased beyond certain limits. Theoretical and graphical solutions are obtained for two possible formulations of the problem, and a simple practical procedure is suggested.     

Theories of Learning in Games and Heterogeneity Bias

Comparisons of learning models in repeated games have been a central preoccupation of experimental and behavioral economics over the last decade. Much of this work begins with pooled estimation of the model(s) under scrutiny. I show that in the presence of parameter heterogeneity, pooled estimation can produce a severe bias that tends to unduly favor reinforcement learning relative to belief learning. This occurs when comparisons are based on goodness of fit and when comparisons are based on the relative importance of the two kinds of learning in hybrid structural models. Even misspecified random parameter estimators can greatly reduce the bias relative to pooled estimation.     

The Couple That Prays Together: Race and Ethnicity,Religion, and Relationship Quality Among Working‐Age Adults

A substantial body of research has shown that relationship quality tends to be (a) lower among racial and ethnic minorities and (b) higher among more religious persons and among couples in which partners share common religious affiliations, practices, and beliefs. However, few studies have examined the interplay of race or ethnicity and religion in shaping relationship quality. Our study addresses this gap in the literature using data from the National Survey of Religion and Family Life (NSRFL), a 2006 telephone survey of 2,400 working‐age adults (ages 18–59), which contains oversamples of African Americans and Latinos. Results underscore the complex nature of the effects of race and ethnicity, as well as religious variables. In particular, we found that couples' in‐home family devotional activities and shared religious beliefs are positively linked with reports of relationship quality.     

Sexual Self-Concept: Testing a Hypothetical Model for Men and Women

One theoretical concept receiving modest attention in contemporary sex research is the sexual self-concept (SSC). However, a lack of cohesion within this research has culminated in a collection of SSC models which overlap one another but which are not exactly the same. Therefore, a unified conceptual model of SSC needs to be established. In addition, little research has examined potential differences between genders in SSC, as most SSC research has focused on women. Using Buzwell and Rosenthal's 1996 Buzwell , S. , & Rosenthal , D. (1996). Constructing a sexual self: Adolescents’ sexual self-perceptions and sexual risk-taking. Journal of Research on Adolescence , 6, 489–513.[Web of Science ®] , [Google Scholar] sexual selves model as a theoretical basis, a six-factor higher-order latent SSC model was tested using confirmatory factor analysis. Lower-order factors for this model included multidimensional sexual self-esteem and sexual self-efficacy factors, as well as unidimensional arousal, anxiety, exploration, and commitment factors. A five-factor latent model (after removing the commitment and the resistance sexual self-efficacy factors) was the best-fitting model. This model was then tested for measurement and structural invariance between genders. Results indicated that while the measurement of SSC was similar between men and women, structural invariance did not hold, as men had a significantly higher latent SSC score compared to women. These findings have important implications for sexual self-concept research, as well as contributing to better understanding of human sexuality.     

Measuring effect size: a robust heteroscedastic approach for two or more groups

Motivated by involvement in an intervention study, the paper proposes a robust, heteroscedastic generalization of what is popularly known as Cohen's d. The approach has the additional advantage of being readily extended to situations where the goal is to compare more than two groups. The method arises quite naturally from a regression perspective in conjunction with a robust version of explanatory power. Moreover, it provides a single numeric summary of how the groups compare in contrast to other strategies aimed at dealing with heteroscedasticity. Kulinskaya and Staudte [16 Rousseeuw, P. J. and Leroy, A. M. 1987. Robust Regression & Outlier Detection, New York: Wiley. [Crossref] [Google Scholar]] studied a heteroscedastic measure of effect size similar to the one proposed here, but their measure of effect size depends on the sample sizes making it difficult for applied researchers to interpret the results. The approach used here is based on a generalization of Cohen's d that obviates the issue of unequal sample sizes. Simulations and illustrations demonstrate that the new measure of effect size can make a practical difference regarding the conclusions reached.     

Lone Motherhood: the Impact on Living Standards of Leaving a Violent Relationship

This paper presents findings from doctoral research which looked at the social support of women leaving domestic violence. In this paper the focus is on one aspect of that study: the living standards of women who have left a violent relationship. An exploratory, area-based study using in-depth interviews and participant observation with twenty white working-class women examinedthis issue. This exploratory study makes visible the links between violence and living standards. Debts incurred during the violent relationship when women had little if any control over finances, rent arrears incurred as a result of leaving, when women were temporarily housed in a refuge or hostel, and increased housing, travel and communication costs all contributed to the women'sexperience of poverty. If findings of previous research are correct, that between 20 and 40 per cent of lone parents (overwhelmingly mothers) experienced domestic violence in their previous relation-ship, then more extensive research in this area is indicated.     

Resilience and risk factors associated with experiencing childhood sexual abuse

The effects of child sexual abuse are wide‐ranging and impact on children, families and health/social care systems. The authors review this literature, examining the shortcomings of the ‘victim–offender’ model, and consider the complex, multifactorial nature of this question. Factors associated with a progression from victim to perpetrator are explored and the prevalence of abuse in the general population is also discussed. Protective as well as risk factors are considered and the pivotal role of ‘personal reliance’ is considered as it relates to empowering damaged young people to become healthy adults. The authors also discuss implications for the treatment of young people who become abusers. Two case examples are brie?y reported upon and the article concludes with a consideration of ways to helpfully address the needs of children who become sexual perpetrators. Copyright © 2004 John Wiley & Sons, Ltd.     

A LIMIT OF BILATERAL CONTRACTING INSTITUTIONS

Nonconvexities undermine the efficiency of the usually robust "double auction" or DA market institution. We experimentally examine two modified DAs that allow for particularly rich bilateral contracting such as arbitrarily nonlinear pricing. The first allows for arbitrarily nonlinear pricing but should not necessarily promote it; the second should promote efficient nonlinear pricing. Experiments support predictions on the emergence of nonlinear pricing, but not those concerning efficiency. Coordination problems are the culprit. We conclude that institutions capable of dealing with some nonconvexities must frequently provide multilateral contracting possibilities not permitted by DA rules and other market-like bilateral contracting institutions. (JEL C92 , D49 , L19 )