The Effect of Product Variety and Inventory Levels on Retail Store Sales: A Longitudinal Study

We examine the effects of product variety and inventory levels on store sales. Using 4 years of data from stores of a large retailer, we show that increases in product variety and inventory levels are both associated with higher sales. We also show that increasing product variety and inventory levels has an indirect negative effect on store sales through their impact on phantom products—products that are physically present at the store, but only in storage areas where customers cannot find or purchase them. Our study highlights a consequence of increased product variety and inventory levels that has previously been overlooked in studies of retail product variety and inventory management. It also quantifies the impact of phantom products on store sales. In addition, our study provides empirical evidence to support earlier claims that higher product variety and inventory levels lead to an increase in defect rate. We discuss the implications of our findings for retail inventory and assortment planning and for the design of retail stores.     

Testing homogeneity of control and treatment populations — local optimality and related issues

Durairajan and Raman (1996 a, b) studied the robustness of Locally most powerful invariant (LMPI) tests for compound normal model in control and treatment populations. In the present paper, the Locally most powerful (LMP) tests are constructed for no contamination in normal mixture model through testing the parameter of mixture of distributions and the mixing proportion. The expected performance of LMP tests are compared using Efron's Statistical Curvature on the lines of Sen Gupta and Pal (1991). The Locally most powerful similar (LMPS) tests for the equality of control and treatment populations in the presence of nuisance parameters are also constructed. Further, the null and non-null distributions of the test statistics are derived and some power computations are made. Received: September 1, 1999; revised version: August 31, 2000     

The World Wide Web as a public relations medium: the use of research, planning, and evaluation in web site development

The World Wide Web is viewed as a desirable medium for public relations by many organizations. Given the evolving nature of the Web and the mixed findings about commercial successes of Web sites, little is known about the managerial aspects of Web site research, planning, and evaluation. This study found that, in many cases, Web site planning is done by trial and error based on subjective knowledge and intuition, with little or no formal research and evaluation.Interviews with persons responsible for making Web site decisions for organizations revealed that competition and the desire to establish an Internet presence were the driving forces in deciding to develop a Web site. Very little research about present effectiveness is done, but there is a strong belief that Web site communication will be increasingly important in the future.Candace White is assistant professor of public relations in the School of Journalism at The University of Tennessee in Knoxville. Niranjan Raman works for The Burke Institute in Cincinnati, Ohio.     

Calibration approach for estimating population total with subsampling of non respondents under single- and two-phase sampling

ABSTRACT

Using the calibration approach, the Hansen and Hurwitz (1946 Hansen, M.H., Hurwitz, W.N. (1946). The problem of non response in sample surveys. J. Am. Stat. Assoc. 46:147–190.[Taylor & Francis Online] , [Google Scholar]) technique-based estimator is developed for the situation where the information on auxiliary variable is assumed known for the entire population units. The double-sampling case has also been dealt with. Expressions for the estimator of population total, its variance, and variance estimator are developed. The theoretical results are illustrated with the help of simulation studies. Simulation results show that the proposed calibration approach-based estimator outperforms the Hansen and Hurwitz estimator.     

The Accessibility of Public Spaces for People with Dementia: a new priority for the 'open city'

The social model of disability de-medicalises disability and politicises it as an issue of universal rights. However, the rights of people with dementia have been less strongly advocated than those of people with physical disabilities. This is particularly the case with environmental planning and design. The needs of people with dementia are now informing the design of residential homes and day centres, but the issue of accessibility to public spaces and amenities has been almost completely neglected. Many outdoor environments such as shopping centres or parks may be inhospitable for people with dementia because they are disorientating, difficult to interpret and navigate, threatening or distressing. The article reviews the literature on indoor design for dementia, reports on research investigating the accessibility of outdoor environments, and describes a new approach using virtual reality technology to enable people with dementia to identify and test outdoor design and planning improvements themselves.     

Creation and evaluation of a maternal mental health course

Perinatal Mood and Anxiety Disorders (PMADs) engender significant and increasing personal, social, developmental, and economic burdens to women, children, families, and global public health. In the US, a Master of Social Work (MSW) elective course, Introduction to Maternal Mental Health, was created to prepare future social workers to better understand, detect, intervene, and advocate with women struggling with perinatal mental health concerns. A pilot study used pre–post-surveys (N = 10) and a focus group to examine students’ knowledge acquisition, course satisfaction, and perceived self-efficacy. A Wilcoxon signed-rank test showed a statistically significant difference between pre- and post-survey course content knowledge scores. Positive focus group feedback and survey outcomes suggest that students benefitted from the course in terms of increased learning and professional efficacy in maternal mental health; however, the study should be replicated using a larger sample and comparison group. The course outline provided may be used to develop a similar course or to infuse maternal mental health content into existing courses. The paper concludes with implications and recommendations for social work educators.     

Contracting in a Supply Chain with Stochastic Demand and Substitute Products

Retailers often stock competing products from multiple manufacturers. When the retailer stocks out of a particular item, customers who prefer the item are likely, with some probability, to switch to a substitute product from another manufacturer at the same store. In such an event, a “lost sale” for the manufacturer is not a “lost sale” for the retailer. This exacerbates differences in manufacturer's and retailer's stockout costs for the item. Such differences in stockout cost influence the optimal contract between the manufacturer and the retailer and also impose agency costs on the channel. Such contracts, in turn, determine equilibrium inventory levels and fill rates. We study these issues in a single‐period supply chain, consisting of a manufacturer and a retailer, under three different scenarios (when the two firms are integrated into a single entity, when the retailer makes stocking decisions, and when the manufacturer makes stocking decisions). We compare, and present a methodology for comparing, stocking quantities, manufacturer efforts, and supply chain profits across different scenarios. We find that VMI performs better when manufacturer effort is a substantial driver of consumer demand and when consumers are unlikely to substitute to another brand in case of a stockout. On the other hand, if non‐contractible manufacturer effort is unimportant, or when substitution is significant, VMI can exacerbate, rather than mitigate, channel inefficiencies, and can perform worse than traditional Retailer Managed Inventory.