The authors thank Anand Bodapati, Randolph Bucklin, Brett Hollenbeck, Elisabeth Honka, Sylvia Hristakeva, Peter Rossi, and Adam Smith for helpful comments. They are very thankful to Andrey Simonov, Jean-Pierre Dubé, Günter Hitsch, and Peter Rossi for sharing their code for the estimation of a model with state dependence that accounts for consumers’ initial conditions and to Andrey Simonov, in particular, for helping them better understand their code. Researchers’ own analyses are calculated (or derived) based in part on data from Nielsen Consumer LLC and marketing databases provided through the NielsenIQ Datasets at the Kilts Center for Marketing Data Center at The University of Chicago Booth School of Business. The conclusions drawn from the NielsenIQ data are those of the researchers and do not reflect the views of NielsenIQ. NielsenIQ is not responsible for, had no role in, and was not involved in analyzing and preparing the results reported herein. All authors certify that they have no affiliations with or involvement in any organization or entity with any financial or nonfinancial interest in the subject matter or materials discussed in this manuscript. The authors have no funding to report.