Abstract: Relevant market definition is one key step in merger review. Critical loss analysis is the popular relevant market definition method. The paper tries to generalize critical loss analysis by relaxing two assumptions, the demand curve is smooth and marginal cost is constant in the range of SSNIP, and proposes a new variant of critical loss analysis which is based on conjecture technology. In order to solve the invalidity of standard critical loss analysis when candidate market has a variety of differentiated products, the paper proposes a new way to implement critical loss analysis. The results show that: (1) statistic and constraint are both different between different versions of critical loss analysis, constraint is the same between different variants of critical loss analysis, but statistic is different between different variants of critical loss analysis; (2) when the demand curve has kinks or marginal costs is variable in the range of SSNIP, current critical loss analysis will define a too wide or too narrow relevant market; (3) when candidate market has a variety of differentiated products, the break-even version of critical loss analysis will be invalid. The paper proposes a new way to implement critical loss analysis which a valid and has strong operability. The paper has two purposes: one is helping parties concerned understand and use critical loss analysis properly; the other is improving Guidelines on Relevant Market Definition.

摘要： 相关市场界定是并购审查的关键环节。临界损失分析是目前世界上界定相关市场的主流方法。本文借助数理模型通过放松在价格上涨区间内需求曲线是平滑的和边际成本不变这两个假设条件，拓展了临界损失分析，并提出了基于推测变分技术的临界损失分析。为了解决备选市场有多种差异化产品时标准的临界损失分析失效的问题，本文提出了新的、具有可操作性的临界损失分析思路。研究结果表明：（1）临界损失不同版本之间的考察指标和约束条件均不同，而同一版本不同思路之间的约束条件相同，但是考察指标不同；（2）当需求曲线存在尖点或边际成本可变时，现有的临界损失分析思路会界定出过宽或过窄的相关市场；（3）当备选市场有多种差异化产品时，本文提出的临界损失分析新思路不仅有效，而且具有较强的可操作性。本文对有关各方准确地理解和应用临界损失分析，完善《关于相关市场界定的指南》，具有重要的理论和现实意义。