Quasi-binomial zero-inflated regression model suitable for variables with bounded support

In recent years, a variety of regression models, including zero-inflated and hurdle versions, have been proposed to explain the case of a dependent variable with respect to exogenous covariates. Apart from the classical Poisson, negative binomial and generalised Poisson distributions, many proposals have appeared in the statistical literature, perhaps in response to the new possibilities offered by advanced software that now enables researchers to implement numerous special functions in a relatively simple way. However, we believe that a significant research gap remains, since very little attention has been paid to the quasi-binomial distribution, which was first proposed over fifty years ago. We believe this distribution might constitute a valid alternative to existing regression models, in situations in which the variable has bounded support. Therefore, in this paper we present a zero-inflated regression model based on the quasi-binomial distribution, taking into account the moments and maximum likelihood estimators, and perform a score test to compare the zero-inflated quasi-binomial distribution with the zero-inflated binomial distribution, and the zero-inflated model with the homogeneous model (the model in which covariates are not considered). This analysis is illustrated with two data sets that are well known in the statistical literature and which contain a large number of zeros.     

REENGINEERING CHANNEL REORDERING PROCESSES TO IMPROVE TOTAL SUPPLY-CHAIN PERFORMANCE

This paper discusses the relationship between business process reengineering and channel performance for firms implementing electronic data interchange (EDI) linkages within the U.S. grocery industry. Both quantitative and qualitative data sources are combined to test the hypothesis that channel transformation involving adoption of EDI and redesign of replenishment processes enables performance improvements more than an order of magnitude greater than implementation of EDI alone. This new process, enabled by EDI, provides retailers with 50- 100% higher inventory turns for products on continuous replenishment processes (CRP) relative to retailer performance using traditional ordering processes. Firms adopting EDI without using CRP to reengineer the ordering processes have failed to realize any statistically significant improvements in either inventory levels or warehouse stockouts. This research provides evidence to support the claims of process reengineering that are common in the popular business press, but for which statistically significant empirical evidence is minimal. The findings of the research also demonstrate the potential improvements that firms can realize through extending the business process reengineering concept to include the firms' entire supply chain.     

Reactive, anxious and possessive forms of jealousy and their relation to relationship quality among heterosexuals and homosexuals

The present study examined the relationship between relational quality and three different types of jealousy-reactive, anxious and possessive jealousy. The sample consisted of 76 gay men, 79 lesbians, 70 heterosexual women and 70 heterosexual men. Findings show that different types of jealousy affect relationship quality differently and do so differently for homosexuals and heterosexuals. Among heterosexuals and especially gay men--but not among lesbians--anxious jealousy was negatively related to relationship quality. In contrast, among heterosexuals--but not among gay men or lesbians--reactive jealousy was positively related to relationship quality. The present study shows that distinguishing between different types of jealousy is necessary to entangle the diverse effects of jealousy on the quality of homosexual and heterosexual relationships.     

Ferment in LGBT studies and queer theory: personal ruminations on contested terrain

The tensions between queer and gay rights theorists, not surprisingly, have grown as queer theory has developed and matured. In this self-reflexive essay, the "contested terrain" between these distinct perspectives is explored, particularly within the discipline of communication studies. The assumptions of queer theory are summarized briefly, and the author takes an autoethnographic approach to demonstrate the constant interplay between lived experience and the basic assumptions of queer theory. The author challenges both LGBT theorists and queer theorists to always consider the implications of their theories and practices.     

Sexual identity distress, social support, and the health of gay, lesbian, and bisexual youth

Sex researchers and mental health clinicians have long recognized that the stigma surrounding homosexuality plays an important role in shaping the social psychological adjustment of gay, lesbian, and bisexual (g/l/b) people. In recent years, researchers have suggested that sexual identity- related distress may influence the physical health status of g/l/b people, primarily because of the ways these self-related feelings and beliefs impact patterns of health-related behavior. This study examines the influence of sexual identity distress and social support on g/l/b youth's drug and alcohol use, psychological distress, and risky sexual behavior. The data come from a services research demonstration program conducted at the Indiana Youth Group, Inc., a g/l/b youth development agency based in Indianapolis, Indiana. Results indicate that sexual identity distress is strongly associated with psychological distress, less frequent use of alcohol, and using fewer types of illegal drugs. Being out to more people in one's support network, however, attenuates the severity of youth's sexual identity-related distress. Youth who report more support ties to g/l/b people indicate engaging in more frequent risky sexual behavior. The implications of these findings for theories of g/l/b youth's sexual identity development are discussed.     

Acknowledgement to editorial collaborators

Acknowledgments

Acknowledgement to editorial collaborators     

SHIFTING PRODUCTION BOTTLENECKS: CAUSES,CURES, AND CONUNDRUMS

We examine the phenomenon of shifting production bottlenecks from an analytic perspective. We quantify the propensity of a work center to be a bottleneck, defined as maximal queue length, using a simple Jackson production network model. Comparison of the analytic model against an empirical simulation-based model shows that the two are in good agreement. A scalar measure of bottleneck shiftiness is proposed and used to investigate several policies for mitigating shiftiness. Simulation experiments show that several commonly observed managerial policies for coping with shifting bottlenecks actually increase shiftiness, but that shiftiness declines when the capacity of nonbottleneck resources is increased.