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.     

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.     

The Career Advancement Prospects of Managers and Professionals: Are MIS Employees Unique?

The present study examined the career advancement prospects of MIS and non-MIS employees, as well as the relationships of career advancement prospects with job performance evaluations, job satisfaction, career satisfaction, and organizational commitment for MIS and non-MIS professionals and managers. Participants included 134 MIS professionals and managers and 397 non-MIS professionals and managers of a large communications company. The results provided no evidence that MIS employees experience more restricted career advancement prospects than non-MIS employees. In addition, job performance evaluations generally had positive effects on career advancement prospects; career advancement prospects had a number of positive effects on job satisfaction, career satisfaction, and organizational commitment; and job satisfaction and career satisfaction had positive effects on organizational commitment. These findings are related to prior research, suggestions for future research are offered, and implications for the management of MIS employees are identified.     

The Contingent-Claims Approach to Investment Decisions*

This paper presents a contingent-claims approach to project valuation when capital expenditures are made sequentially over time. It focuses on an important facet of sequential investment projects that the firm can undertake—or pass up projects—as more information becomes available. The contingent-claims approach takes account of this important feature of firms' investment decision process, whereas the traditional capital budgeting procedure does not. Since the traditional method does not reflect the options nature of investment opportunities, it underestimates the value of sequential investment projects. As a result, a naive implementation of the traditional capital budgeting procedure could result in rejecting profitable projects. The extent of undervaluation associated with the traditional capital budgeting procedure is greater when the correlation between the random component of the future asset value and that of the required capital expenditure is smaller and/or when the growth rate of the required capital expenditure is higher.     

Life Satisfaction of Rural Migrant Workers in Urban China: The Roles of Community Service Participation and Identity Integration

Abstract

China is home to approximately 245 million rural-to-urban migrant workers. The influx of migrants into urban areas has posed various challenges for local social service systems. Recently, increasing number of community services have been developed to meet the growing service demands from the migrant population. However, whether increase in community service use results in improved wellbeing among migrant workers remains critically unexplored. As such, this study examines the role of community service use in migrant workers’ life satisfaction and the potential mediating effect of identity integration in Shenzhen, China. Bootstrapped models were adopted to examine relationship among variables. Drawing from a sample of 1,087 rural-to-urban migrant workers, we found that community service use is positively correlated with both identity integration and migrant workers’ life satisfaction. Moreover, identity integration served as a partial mediator between community service use and life satisfaction. The mediating effect of identity integration was found to increase with age. This study highlights that diverse services should be implemented to address divergent needs of migrants in different age groups. Community service can also serve as a vehicle to foster integration among migrant workers in host communities, especially for older age groups. Future studies may further investigate the relationships between community social capital, community social support, quality of community-based organization and frequency of service use so as to optimize the life satisfaction of migrant workers.