Abstract 



A person chooses a store to shop at partly on the basis of the 

 difficulty of getting there. An understanding of the relation- 

 ships involved is important in marketing strategy, particularly 

 for site selection purposes. We study an urban new-car market. 

 As a measure of shopping difficulty, the distance from a person's 

 residence to the car dealer is used. Assumptions about buyer 

 behavior lead to a model of competitive interaction among dealers 

 and car makes. The model is fitted to three months of sales data 

 for metropolitan Chicago. An interactive computer system has 

 been programmed to make the model available for on-line investi- 

 gation of a variety of site selection and inter-brand competition 

 questions. For example, a user can add, eliminate, or move a 

 dealer and then ask for the model-predicted changes in the sales 

 and penetration of any dealer or make. 



