Economic analysis of competition regulation is most developed in the domain of horizontal mergers, and modern agency guidelines reflect a substantial consensus on the appropriate template for merger assessment. Nevertheless, official protocols are understood to rest on a problematic market definition exercise, to use HHIs and ΔHHIs in ways that conflict with standard models, and more broadly to diverge with how economic analysis of proposed mergers should be and often is conducted. These gaps, unfortunately, are more consequential than is generally appreciated. Moreover, additional unrecognized errors and omissions are at least as important: analysis of efficiencies, which are thought to justify a permissive approach, fails to draw on the most relevant fields of economics; entry is often a misanalyzed afterthought; official information collection and decision protocols violate basic tenets of decision analysis; and single-sector, partial equilibrium analysis is employed despite the presence of substantial distortions (many due to imperfect competition) in many sectors of the economy. This article elaborates these deficiencies, offers preliminary analysis of how they can best be addressed, and identifies priorities for further research.

竞争监管的经济分析在横向并购领域最为发达，现代代理准则反映了对并购评估适当模板的实质性共识。尽管如此，官方协议被理解为基于有问题的市场定义练习，以与标准模型冲突的方式使用 HHI 和 ΔHHI，并且更广泛地与应如何和经常进行拟议合并的经济分析存在分歧。不幸的是，这些差距比人们普遍认为的更重要。此外，其他未被承认的错误和遗漏至少同样重要：效率分析被认为证明了一种宽容的方法是合理的，但未能利用最相关的经济学领域；进入往往是一个误判的事后想法；官方信息收集和决策协议违反决策分析的基本原则；和单一部门，尽管许多经济部门存在实质性扭曲（许多由于不完全竞争），但仍采用部分均衡分析。本文详细阐述了这些缺陷，提供了如何最好地解决这些缺陷的初步分析，并确定了进一步研究的优先事项。