Effects of the 2010 Horizontal Merger Guidelines on Merger Review: Based on Ten Years of Practical Experience.

We assess how the 2010 Merger Guidelines have been applied by agencies and courts. We conclude that: Increased reliance on direct evidence of market power has improved the analysis of mergers, but courts still sometimes overemphasize market definition. Market concentration thresholds remain a reflection of agency practice rather than economic research. The Upward Price Pressure concept yields useful intuition, but UPP can be overused. The benefits that could arise from the renewed focus on coordinated effects are squandered by the lack of a rigorous economic framework recognizing the connection to unilateral effects. The lack of merger retrospectives remains a problem. [ABSTRACT FROM AUTHOR]