Rising Concentration of Household Shopping, Superstar Firms, and Implications for Retail Markups
研究了2004至2019年美国零售业家庭购物集中度上升的现象，发现超级零售商增多、店内产品种类增加和网购兴起是主因，并估算出零售加价上升了5到10个百分点。
This paper documents an increase in the concentration of household shopping in the United States retail sector from 2004 to 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, the rise 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.