Dr. Greg Allenby
Helen C. Kurtz Chair in Marketing
Fisher College of Business
The Ohio State University
Title: Is Your Sample Truly Mediating? Bayesian Analysis of Heterogeneous Mediation (BAHM)
Abstract: Mediation analysis is used to study the relationship between stimulus and response in the presence of intermediate, generative variables. The traditional approach to the analysis utilizes the results of an aggregate regression model, which assumes that all respondents go through the
same data-generating mechanism. We introduce a new approach that is able to uncover the heterogeneity in mediating mechanisms and provides more informative insights from mediation studies. The proposed approach provides individual-specific probabilities to mediate as well as a
new measure of the degree of mediation as the prevalence of mediation in the sample. Covariates in the proposed model help describe the variation in the probability to mediate among respondents. The empirical examination of published studies demonstrates the presence of heterogeneity in mediating processes and supports the need for this new approach. We present evidence that the results of our more flexible heterogeneous mediation analysis do not necessarily agree with traditional aggregate measures. We find that the conclusions from the aggregate analysis are neither sufficient nor necessary to claim mediation in the presence of heterogeneity. A web-based application allowing researchers to analyze the data with the
proposed model in a user-friendly environment is developed.
Dr. Greg Allenby's research focuses on the development and application of quantitative methods in marketing. He is the author of two books: Bayesian Statistics and Marketing (2005, Wiley) that is used to train doctoral students throughout the world, and Seven Summits of Marketing Research (Links to an external site.) (2014) that is used for MBA students. His research is used to improve product, pricing, promotion and targeting strategies at leading firms.
He is a fellow of the Informs Society for Marketing Science and the American Statistical Association. He is past editor of Quantitative Marketing and Economics, and past associated editor of Marketing Science, Management Science, Journal of Marketing Research and the Journal of Business and Economic Statistics. Within the American Marketing Association, Greg has served as Vice President of the Research Council and has chaired the Advanced Research Technique (ART) Forum, a national conference that brings together quantitative researchers from industry and academia. Within the American Statistical Association, he has served as Chair of the Section on Statistics in Marketing. He has authored over 100 publications that have appeared in leading journals in marketing, statistics and economics.