Demand Complementarities, Household Production, and Retail Assortments

This paper presents a formal model of retail demand, based upon a household production framework, that permits rigorous analysis of retail assortments. The model captures the essential shifting of distribution costs between retailers and consumers that manifests itself in retailers' provision of distribution services for consumers. We apply the model to define rigorously conventional retailing concepts, such as assortment breadth and depth, and to explain the appearance of certain well-known phenomena such as market-basket pricing, nonprice retail competition, and the incentives for retail agglomerations to form. Throughout, distribution services play a critical role in binding together the analytical model and the diverse reality giving rise to retail assortments.