Markups Across Space and Time
研究了零售业加价在时间和空间上的变化，发现加价相对稳定且温和顺周期，区域间差异大，且与当地收入正相关，差异源于商品组合不同。
Abstract In this article, we provide direct evidence on the behaviour of markups in the retail sector across space and time. Markups are measured using gross margins. We consider three levels of aggregation: the retail sector as a whole, the firm, and the product level. We find that: (1) markups are relatively stable over time and mildly procyclical; (2) there is a large regional dispersion in markups; (3) there is a positive cross-sectional correlation between local income and local markups; and (4) differences in markups across regions result from differences in the assortment of goods sold in different regions, not from deviations from uniform pricing. We propose a simple model consistent with these facts.