Unplanned Buying By Supermarket Shoppers

David Bell, The Wharton School, University of Pennsylvania, USA
Daniel Corsten , Instituto de Empresa Business School, Spain
George Knox , Tilburg University, the Netherlands
We hypothesize three generic factors—shopper predispositions (including demographics and shopping habits), store environments, and shopping trip contexts—affect the unplanned buying cost-benefit calculus. Using panel data and a multi-level random effects Poisson model we find a high degree of within-household clustering in the number of unplanned categories in the shopping basket (for two trips by the same household, the intra-class correlation is .579). Thus, the majority of variation is across shoppers (rather than stores or trips), and partly explainable by demographics, but more by “traits” that reflect long-run shopping habits. Trip antecedents, types, and in-store experiences are also influential.
[ to cite ]:
David Bell, Daniel Corsten , and George Knox (2010) ,"Unplanned Buying By Supermarket Shoppers", in NA - Advances in Consumer Research Volume 37, eds. Margaret C. Campbell, Jeff Inman, and Rik Pieters, Duluth, MN : Association for Consumer Research, Pages: 191-194 .