MODELING CONSUMERS CHOICES OF MULTIPLE ITEMS

Contemporary choice models focus on choice opportunities in which cons umers purchase a quantity of a single item in a product category, Howe ver, failing to recognize the possibility of assortments of multiple-i tem purchases can lead to incorrect conclusions about the impact of pa st purchase behavior on current choices. The authors propose a model t hat allows for multiple-item shopping trips and apply it to scanner da ta for powdered soft drinks. The model provides descriptions about the influence of (1) consumer's prior behavior across previous shopping t rips, (2) behavior within the same shopping trip, (3) the in-store she lf assortment available at the time of purchase, and (4) marketing mix variables on multiple-item shopping trip choices, The authors' model provides better choice predictions in a holdout sample at the aggregat e and assortment composition levels than a traditional, single-purchas e choice model. Using the model, they present simulation and naturally occurring experiment results in the powdered soft drinks category, Fi nally, they discuss the value of their results for understanding the c onsequences of consumers' choices and their implications for manufactu rers.