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.     

Managing Retail Budget Allocation between Store Labor and Marketing Activities

The performance of a retail store depends on its ability to attract customer traffic, match labor with incoming traffic, and convert the incoming traffic into sales. Retailers make significant investments in marketing activities (such as advertising) to bring customers into their stores and in‐store labor to convert that traffic into sales. Thus, a common trade‐off that retail store managers face concerns the allocation of a store's limited budget between advertising and labor to enhance store‐level sales. To explore that trade‐off, we develop a centralized model to allocate limited store budget between store labor and advertising with the objective of maximizing store sales. We find that a store's inherent potential to drive traffic plays an important role, among other factors, in the relative allocation between advertising and store labor. We also find that as advertising instruments become more effective in bringing traffic to stores, managers should not always capitalize this effectiveness by increasing their existing allocations to advertising. In addition, we discuss a decentralized setting where budget allocation decisions cannot be enforced by a store manager and present a simple mechanism that can achieve the centralized solution. In an extension, we address the budget allocation problem in the presence of marketing efforts to shift store traffic from peak to off peak hours and show that our initial findings are robust. Further, we illustrate how the solution from the budget allocation model can be used to facilitate store level sales force planning/scheduling decisions. Based on the results of our model, we present several insights that can help managers in budget allocation and sales force planning.     

Linking Perceived Quality and Customer Satisfaction to Store Traffic and Revenue Growth*

Effects of perceived merchandise and service quality, relative to competition, on retail store performance are investigated using store traffic and revenue growth as outcome variables. A model is proposed and tested using aggregate customer data and store performance outcomes from a group of stores owned by a national retail organization. Results suggest that both service and merchandise quality exert significant influence on store performance, measured by sales growth and customer growth, and their impact is mediated by customer satisfaction. Implications of the results and future research directions are discussed.     

Optimal responses to stockouts: Lateral transshipment versus emergency order policies

In the retail industry, stockouts have a significant effect on a firm׳s profitability. When a stockout takes place, retailers often apply one of two strategies to resolve the issue – placing an emergency order with their supplier or arranging a lateral transshipment with a nearby partner store. Choosing the optimal response to a stockout is complicated by customers׳ spontaneous reactions. Customers who find that a product is out of stock may choose to give up on the purchase, to wait for delivery (through emergency order or lateral transshipment), or go to a partner store to search for the product on their own. In this study, under a single-period setting with two retail stores, we investigate the optimal inventory decisions under each strategy, and conduct a comparison between lateral transshipment and emergency order options. We also analyze the effects of the customer requesting rate and switching rate on the optimal inventory decision. Through numerical analysis, the two strategies are compared in terms of inventory levels and profitability. The results suggest that in addition to the cost associated with each of these strategies, the customers׳ behavior in response to a stockout has a significant effect on the optimal decision. The emergency order strategy is a better option when more customers request deliveries or when more customers switch to another store. Extending this analysis, we also examine the combined strategy when an emergency order is placed after a transshipment fails to fulfill unmet demands, and explore the circumstances under which this strategy provides the highest additional profit for the stores. Finally, we also find that a higher requesting rate does not necessarily increase profits, particularly when there is a high customer switching rate, because requesting emergency order or transshipment reduces switching demand.     

In‐Store Experiments to Determine the Impact of Price on Sales

This paper describes an experimentation methodology to measure how demand varies with price and the results of its application at a toy retailer. The same product is assigned different price‐points in different store panels and the resulting sales are used to estimate a demand curve. We use a variant of the k‐median problem to form store panels that control for differences between stores and produce results that are representative of the entire chain. We use the estimated demand curve to find a price that maximizes profit. Our experiment yielded the unexpected result that demand increases with price in some cases. We present likely reasons for this finding from our discussions with retail managers. Our methodology can be used to analyze the effect of several marketing and promotional levers employed in a retail store besides pricing.     

A Sales Forecast Model for Short‐Life‐Cycle Products: New Releases at Blockbuster

We develop, in this article, a sales model for movie and game products at Blockbuster. The model assumes that there are three sales components: the first is from consumers who have already committed to purchasing (or renting) a product (e.g., based on promotion of, or exposure to, the product prior to its launch); the second comes from consumers who are potential buyers of the product; and the third comes from either a networking effect on closely tied (as in a social group) potential buyers from previous buyers (in the case of movie rental and all retail products) or re‐rents (in the case of game rental). In addition, we explicitly formulate into our model dynamic interactions between these sales components, both within and across sales periods. This important feature is motivated by realism, and it significantly contributes to the accuracy of our model. The model is thoroughly tested against sales data for rental and retail products from Blockbuster. Our empirical results show that the model offers excellent fit to actual sales activity. We also demonstrate that the model is capable of delivering reasonable sales forecasts based solely on environmental data (e.g., theatrical sales, studio, genre, MPAA ratings, etc.) and actual first‐period sales. Accurate sales forecasts can lead to significant cost savings. In particular, it can improve the retail operations at Blockbuster by determining appropriate order quantities of products, which is critical in effective inventory management (i.e., it can reduce the extent of over‐stocking and under‐stocking). While our model is developed specifically for product sales at Blockbuster, we believe that with context‐dependent modifications, our modeling approach could also provide a reasonable basis for the study of sales for other short‐Life‐Cycle products.     

The changing structure of food retailing in europe: the implications for strategy

European food retailers have increased their scale and scope while concentrating sales into large stores. Strategic implications include the need for scale to compete and organisational relationships to move from supply push to demand pull retailing. Consequences are different for private label and for branded manufacturers, who must respond to the demands of retail supply chains whilst retaining control of product development. Further concentration in both sectors is likely. Consumers are more mobile, but more captive to the retailer in store. Public policy makers are challenged to find new measures of retail power and both allow for innovation and ensure equitable shopping opportunities.     

What Happens When Manufacturers Perform The Retailing Functions?

This study examines the effects of a relatively new channel structure on prices and sales in a large department store, which in recent years has switched the management of many of its product categories from a traditional retailer‐managed system to a manufacturer‐managed system. We find that the change caused overall retail prices to decrease. However, there was significant heterogeneity in the response across brands. In the cell phone category, brands with high market shares and inelastic demand did not change prices. In the watch category, the retail prices of relatively low‐end brands decreased while the prices of premium brands increased substantially after the switch. In addition to sales increases due to lower prices, we find that the channel structure change further caused sales to increase by 9–10% in the cell phone category and by 11–17% in the watch category. These results are consistent with previous theoretical predictions. We believe that our results provide important academic and managerial implications due to the increasing prevalence of manufacturer‐managed systems in the retail industry.     

Self‐Service Operations at Retail Stores: The Role of Inter‐Customer Interactions

Inter‐customer interactions are important to the operation of self‐services in retail settings. More specifically, when self‐service terminals are used as part of customers’ checkout processes in retail operations without the explicit involvement of retailers as the direct service providers, inter‐customer interactions become a significant managerial issue. In this article, we examine the impact of inter‐customer interactions at retail self‐service terminals on customers’ service quality perceptions and repeat purchase intentions at retail stores. We conduct a scenario‐based experimental design (N = 674) using a 2 × 2 factorial design in which inter‐customer interactions are divided into “positive” vs. “negative” and occur during the “waiting” or during the actual “transaction” stages of self‐services at a retail store. We use attribution theory to develop the hypotheses. The results demonstrate that, through their interactions, fellow customers can exert influences on a focal customer's quality perceptions and repeat purchasing intentions toward a retail store. Furthermore, these influences were impacted by how customers attribute blame or assign responsibility toward the retail store. Service operations managers should leverage these interactions by designing into self‐service settings the capacities and interfaces that are best suited for customers’ co‐production of their self‐service experiences.     

Traffic‐Based Labor Planning in Retail Stores

Staffing decisions are crucial for retailers since staffing levels affect store performance and labor‐related expenses constitute one of the largest components of retailers’ operating costs. With the goal of improving staffing decisions and store performance, we develop a labor‐planning framework using proprietary data from an apparel retail chain. First, we propose a sales response function based on labor adequacy (the labor to traffic ratio) that exhibits variable elasticity of substitution between traffic and labor. When compared to a frequently used function with constant elasticity of substitution, our proposed function exploits information content from data more effectively and better predicts sales under extreme labor/traffic conditions. We use the validated sales response function to develop a data‐driven staffing heuristic that incorporates the prediction loss function and uses past traffic to predict optimal labor. In counterfactual experimentation, we show that profits achieved by our heuristic are within 0.5% of the optimal (attainable if perfect traffic information was available) under stable traffic conditions, and within 2.5% of the optimal under extreme traffic variability. We conclude by discussing implications of our findings for researchers and practitioners.     

On‐Shelf Availability,Retail Performance,and External Audits: A Field Experiment

A potential answer to retailer's shelf out‐of‐stocks (OOS), where the item is in the store but customers cannot find it, is to employ third‐party service providers to execute audits and corrections. However, given the nontrivial cost of executing external audits, it is still necessary to assess whether external audits are capable of reducing shelf‐OOS, whether they can be performed in an economical way, and whether the benefits from the audits translate into higher sales. In an effort to address these questions, we partnered with a product manufacturer and a retail service provider and conducted a field experiment in a national retailer's store set. We used transactional data to detect abnormal operations and respond to possible shelf‐OOS by sending auditors to correct empty shelves and incorrect inventory records. At the conclusion of the experiment, we found that Stock Keeping Units in the treatment group were less likely to have shelf‐OOS and inventory record inaccuracies, and that our intervention had a positive effect on sales. Furthermore, we found that the external audit initiative is economically viable since these improvements required low auditing efforts after a transitional period, and in steady state the cost of running the program is a small fraction of the benefits it generates. We discuss the limitations of our study and the implications of our findings for researchers and practitioners.     

Efficiency in a departmental store group

Effective measurement of efficiency levels and changes in these through time is an important yet difficult area of managerial activity. The approach advocated by MJ Farrell has much to commend it, although it also suffers from limitations. This paper demonstrates how the technique was applied to comparing the efficiency of different outlets in a departmental store group. It was found that efficiency gains over time were more marked in the use of labour than in the use of space and reasons are advanced to explain why this is not surprising. While it was not expected that efficiency and profitability would necessarily be closely correlated, there was some suggestion in the evidence that in many instances more efficient stores had higher profits and also that the more efficient stores (apart from those at the very highest efficiency levels) were larger and achieved a higher proportion of total sales through their own departments.     

In-Store Experimental Approach to Pricing and Consumer Behavior

This study assessed how, and to what extent, it is possible to use behavioral experimentation and relative sales analysis to study the effects of price on consumers' brand choices in the store environment. An in-store experiment was performed in four stores to investigate the effects of different prices of a target brand on consumers' relative buying behavior using an alternating treatment design with baseline. The intervention consisted of periodically reducing the target brand's price by 17–26%. Price reductions generally had none or minor effects. However, data for one store showed lower relative sales for the price reduction condition. These are surprising results and they underline the need to examine all of the marketing mix factors, not only price.     

Assessing Markups,Service Quality,and Product Attributes in Music CDs' Internet Retailing

We investigate trade‐offs among markups, service quality, and product attributes across customer, Internet retailer, and wholesaler echelons. Research has documented the reality of retail price dispersion, but little is known about how retail markups, in particular, are related to service quality and product attributes. For example, do Internet retailers deliver superior service in return for high markups? Do product characteristics affect the relationship between service and markups for retailers? To examine these issues, we first developed a model of Internet retail profitability that separates revenues and costs related to sales from other profit sources. This framework allowed us to position our work alongside the extant literature about Internet retailing. Moreover, it led us to synthesize service quality dimensions found in Internet retailing studies. We subsequently developed a critical‐event study based on the profit model and the synthesis of service quality dimensions to delineate service aspects that retailers should emphasize to address buyers' utility. Finally, we collected data from Internet purchases across retailers to isolate markup‐service quality trade‐offs along our delineated service aspects. We find that high markups are associated with superior performance across service quality dimensions. Furthermore, this trade‐off becomes more acutely defined when products with variable popularity are transacted.     

Zur Berücksichtigung von Heterogenit?t versus funktionaler Flexibilit?t in Absatzreaktionsmodellen: Eine empirische Studie auf Basis von Handelsdaten

In this paper, we explore the differences between store sales models that allow for heterogeneity in marketing effects across stores and models that accommodate potential irregularities in sales response through the use of nonparametric estimation techniques. In particular, we investigate the following question: What benefits can we gain from incorporating store heterogeneity versus functional flexibility in sales response models concerning fit and predictive validity, as compared to a simple parametric store sales model? In an empirical study based on store-level data, we also compare the different model versions with respect to estimated price elasticities and resulting shapes for own- and cross-price effects. Our empirical results indicate that addressing heterogeneity is not advantageous in general, as model fit, predictive validity and the accuracy of price elasticities did not improve for many brands. In contrast, estimating sales response flexibly provides much more potential for statistical improvements and leads to different implications concerning price elasticities, too.     

The Backroom Effect in Retail Operations

Traditional inventory models fail to take into account the dynamics between the retail sales floor and the backroom, commonly used by retailers for extra storage. When a replenishment order for a given item arrives at a retail store, it may not fit on the allocated shelf space, making backroom storage necessary. In this article, we introduce the backroom effect (BRE) as a consequence of misalignment of case pack size, shelf space, and reorder point. This misalignment results from the fragmented nature of inventory policy decision making in the retail industry and affects basic trade‐offs in inventory models. We specify conditions under which the BRE exists, quantify the expected amount of backroom inventory, derive an optimal short‐term inventory policy, and assess the impact of the BRE on the optimal inventory policy and total costs. Our results indicate that ignoring the BRE leads to artificially high reorder points and higher total costs. The paper concludes with a discussion of theoretical and managerial implications.     

考虑实体店公平关切的制造商线上入侵策略研究

在单一线下模式销售的基础上,考察制造商以转销模式进行线上入侵和以代销模式进行线上入侵这两种模式,通过数理推导和数值仿真得到的研究结果表明：（1）当实体店具有公平关切心理时,制造商进行线上入侵总是有利的。（2）当消费者对线上渠道接受程度较高且实体店公平关切程度较低时,制造商将以转销模式进行线上入侵;当消费者对线上渠道接受程度较低时,制造商会以代销模式进行线上入侵,并不受实体店公平关切程度的影响;而当消费者对线上渠道接受程度适中且实体店的公平关切程度较高时,制造商倾向于以转销模式进行线上入侵。（3）无论制造商选择哪种模式进行线上入侵,制造商的线下零售价格始终高于线上。此外,随着实体店公平关切程度的增强,线上渠道和线下渠道的零售价均会同步提高。     

An Information‐Processing Approach for Evaluating In‐Store Retail Operational Design Strategies

We develop a model to evaluate retail store operational design strategies using an information‐processing perspective of organizational design. We propose that three model constructs pertaining to in‐store shopper task uncertainty—the product mix complexity, the service production complexity, and the product mix changeover—create shopper encounter information requirements (IR). These requirements can be met using specific retail service operational design choices for managing shopper encounters, namely, designing layouts for self‐service (SS) and providing employees with task empowerment (TE). The model is then operationalized using a two‐stage approach to develop new multi‐item, measurement scales. The psychometric properties and predictive validity of the scales and model are then confirmed by using structural equation modeling with survey data from 175 merchandise retail store managers. We find that our model can be generically applied across the retail industry to understand how shopper encounter IR motivate retailer store design choices and can be used to determine whether to design stores for SS or to provide store employees with TE. We then evaluate the efficacy of the studied store design choices on customer delivery satisfaction, and offer some suggestions for future research.     

RFID for Better Supply‐Chain Management through Enhanced Information Visibility

Mostly fueled by mandates, adoption, and implementation of the RFID, technology in the retail industry is growing rapidly. At these early stages of adoption, one puzzling issue for retailers and suppliers is the compelling business case for RFID. In order to explore the potential business case for RFID, we conducted a case study using actual RFID data collected by a major retailer for the cases shipped by one of its major suppliers. We show the physical layout of the RFID readers on a partial supply‐chain covering product movement from distribution centers to retail stores. First, in the analysis phase, we identify several performance metrics that can be computed from the RFID readings. Next, using this RFID data, we compute the values of those performance metrics. These values represent mean time between movements at different locations. Then, we discuss how these measures can assist in improving logistical performance at a micro supply chain level of operations between a distribution center and a retail store. We present how such information can be valuable to both the retail store operator and the supplier. We also discuss the initial lessons learned from actual RFID data collected in the field, in terms of data quality issues.     

Examining the Effects of a Low-Cost Prompt to Reduce Retail Theft

The present study evaluated the extent to which a low-cost, antitheft intervention impacted theft and sales in a multiple baseline design across two grocery stores. Previous research has measured the impact on theft of items that have a sign indicating their high theft rate and stickers next to or on the items. In contrast, this study tracked four intervention groups: a group directly marked with a sign and ribbons, two indirectly targeted groups (sign-only and a group down the aisle from the sign-only), and a group with no intervention. Results indicated the largest decrease in theft for one of the indirectly targeted groups, from 45 total items stolen to 13, compared to a smaller decrease in theft (i.e., 64 to 40) for the directly targeted sign and ribbons products. Implications of these findings for applying behavior-based antitheft interventions in retail businesses are discussed and future research is proposed.