The authors explore product category and customer characteristics that affect consumers’ likelihood of engaging in
unplanned purchases. In addition, they examine consumer activities that can exacerbate or limit these effects. The
authors employ a hierarchical modeling approach to test their hypotheses using a data set of in-store intercept
interviews conducted with 2300 consumers across 28 stores. The results show that category characteristics, such
as purchase frequency and displays, and customer characteristics, such as household size and gender, affect
in-store decision making. Moreover, although the analysis reveals that the baseline probability of an unplanned
purchase is 46%, the contextual factors can drive this probability as high as 93%. The results support the
predictions that list use, more frequent trips, limiting the aisles visited, limiting time spent in the store, and paying
by cash are effective strategies for decreasing the likelihood of making unplanned purchases.