Ten years after their release, the 2010 Horizontal Merger Guidelines continue to reflect accurately current legal and economic principles of antitrust. Despite fears to the contrary, the Antitrust Division still relies on market shares and concentration—along with a wide range of other evidence—to determine whether a merger is likely to harm competition substantially. Similarly, market definition remains an essential ingredient to merger analysis, combining the quantitative rigor of the hypothetical monopolist test with the kinds of qualitative evidence that date back to Brown Shoe. The 2010 Horizontal Merger Guidelines have also contributed to courts’ increasing acceptance of the standard economic tools that are used to quantify the potential impact of horizontal mergers, including merger simulation and upward pricing pressure.

发行十年后，《 2010年横向并购指南》继续准确反映当前反托拉斯的法律和经济原则。尽管有相反的担心，但反托拉斯部门仍然依靠市场份额和集中度以及大量其他证据来确定合并是否可能实质性损害竞争。同样，市场定义仍然是合并分析的重要组成部分，将假设垄断者测试的定量严谨性与可追溯到Brown Shoe的各种定性证据相结合。《 2010年横向并购指南》还有助于法院越来越多地接受用于量化横向并购潜在影响的标准经济工具，包括并购模拟和向上定价压力。