For a number of years, commentators have debated whether the United States has a monopoly problem. But as part of the recent conversation over the direction of antitrust law and the continued appropriateness of the consumer welfare standard, the debate has turned to whether the antitrust agencies are paying enough attention to monopsony issues. A concept that appears more in textbooks than in case law has suddenly become mainstream and practitioners should be aware of developments when they counsel clients on issues involving supply-side concerns.