产品市场集中度

中文摘要

本文测度了1994年至2019年间美国各类消费品与服务在狭义定义的产品市场中的集中度。我们记录了两个主要的经验事实。第一,集中度水平较高。样本中44.4%的市场属于美国监管机构所定义的“高度集中”市场。第二,自1994年以来市场集中度持续下降,中位数HHI从2362降至2045。这些发现与既有文献形成鲜明对比,后者使用的市场定义被加总至通常过宽的层面,难以准确反映消费市场的竞争状况。

Abstract

This paper measures concentration in narrowly defined product markets for a broad range of consumer goods and services in the U.S. from 1994 to 2019. We document two main empirical facts. First, concentration levels are high. 44.4% of the markets in our sample are “highly concentrated” as defined by U.S. regulators. Second, market concentration has been decreasing since 1994. The median HHI falls from 2362 to 2045. These findings stand in stark contrast to the prior literature, which uses market definitions that are aggregated to a level that is typically too broad to accurately reflect competition in consumer markets.