Studying patterns of consumer's grocery shopping trip

Previous research on (grocery) shopping trips has focused on studying the relationship between shopping frequency and shopper's demographic characteristics. Recognizing that shoppers are heterogeneous in terms of their shopping trip regularity as well as shopping frequency, we propose a mixture model of the exponential and the Erlang-2 distribution with heterogeneous frequency for shopping trip intervals. Applied to IRI (Information Resources, inc.) shopping trip data, we found that 70 percent of shoppers visit grocery st6res with random intervals and 30 percent with relatively fixed intervals. We also found clear differences between these "random" and "routine" shoppers in terms of several demographic and purchase behavioral characteristics. The "routine" shoppers are identified to have higher opportunity costs which make it difficult for them to visit grocery stores more often and/or to switch stores. However, they spend more dollars for a given shopping trip. Finally, we discuss managerial iniplications of segmenting shoppers by their shopping trip regularity.