Do Household Scanner Panel Data Provide Representative Inferences from Brand Choices

The authors investigate whether household scanner data provide rep- resentative inferences about brand choice behavior. They show the (ana- lytical) equivalence of the homogeneous brand choice logit and the multi- nomial store sales models. Then, they determine how results for the homogeneous logit model estimated with actual household data deviate from results for the multinomial model estimated with actual store data from the same community. They also perform this comparison using model specifications that provide average estimated parameters while accommodating unobserved household heterogeneity. The authors find statistical support for the hypothesis that panelist households are not rep- resentative, whether household heterogeneity is or is not accommodated. Substantively, however, the average estimated price elasticities are close for the household and store data analyzed, if the household data are selected on the basis of purchase selection. An alternative selection pro- cedure, called household selection, which is used for the analysis of com- plete household purchase records, provides results that strongly differ from the purchase selection re