Data and Code for: Rising Concentration of Household Shopping, Superstar Firms, and Implications for Retail Markups

This paper documents an increase in concentration of household shopping in the US retail sector from 2004-2019. Despite a growing number of stores, households visit fewer stores, do more one-stop shopping, and increasingly shop at different retailers from each other. We find that the increasing availability of superstar retailers, rises in product variety within stores, and the rise of online shopping contribute to these trends. We explore how these trends are linked with rising retail markups. Our calibration suggests a 5-10 percentage point increase in aggregate retail markups during this period.