Polygamous Store Loyalties: An Empirical Investigation

Grocery store loyalty has been traditionally viewed as a trait of consumers toward a particular store for their overall shopping needs. In this study, we argue that store loyalty shall be regarded as category specific trait, that is, a consumer could be loyal to store A in category one while at the same time be loyal to store B in category two. We name this consumer behavior polygamous store loyalties. We use an in-home scanning panel dataset that tracks purchases of 1,321 households in 284 grocery categories across fourteen retail chains over a 53-week period in a large US market. First, we provide model free evidence of polygamous store loyalties in the data, even though the overall store loyalty based on the traditional view is low. Next, we propose a model to separate category specific effects from overall store level effects. Finally, we discuss how retailers can use the results to gain a new perspective on store attractiveness to improve overall store patronage.