The June 2022 issue of CPI Antitrust Chronicle includes the article by AAI’s Diana Moss: Market Power in Supply Chains. As supply chains have grown in sophistication and complexity, so too have the competition issues they raise. Years of consolidation and rising concentration in the critical middle segments of major supply chains have created market power “bottlenecks.” These bottlenecks have a number of important implications. For example, dominant firms and oligopolies in these middle markets can often exercise market power on both the buyer side and seller side. Moreover, strong incentives for players to bulk up to counter the bargaining power of suppliers and distributors has exacerbated consolidation, with serious implications for the stability and resiliency of supply chains—as we have seen during the COVID-19 pandemic. This article examines the problem of market power in supply chains using the pharmaceutical and food & agriculture sectors as mini-case studies. It highlights weak merger control in the U.S. as a source of the problem and key priorities for strengthening enforcement to address it.