See below for a link to an interview on my research on soda taxes with Anna Tuchman and Song Yao. This video was filmed a few months ago when I was still at Stanford, but has only been cut and edited recently. I summarize the findings of our research based on data from Philadelphia and outline what we can learn from the Philadelphia experience for the design of similar taxes going forward.


It is a well-known stylized fact in quantitative marketing that consumers are highly persistent in their product choices. Such persistence has typically been rationalized through strong heterogeneity in preferences across consumers. In a (recently updated) working paper with Xiaojing Dong, Ilya Morozov, and Liwen Hou, we show that even mild preferences for specific products can lead to persistent choices if consumers only evaluate a limited set of options. We show that when data on search and purchase behavior is available, we can disentangle the role of preferences and search frictions, and taking search costs into account leads to smaller estimates of preference heterogeneity. As a consequence there is less scope for targeted marketing.

Many online retailers sell hundreds of different products, which makes optimal price setting a difficult task that requires the retailer to understand substitution patterns between similar products in their assortment. In a new working paper (joint with Tomomichi Amano and Andrew Rhodes) we propose a demand model that leverages information on which products consumers tend to search (i.e. browse) together before making a purchase. Such data on search behavior is often collected by online retailers, more abundant than purchase data, and highly informative about product similarity and hence substitutability.