中文摘要：

横向并购可能产生的反竞争效应包括单边效应和协调效应两种，对单边效应进行评估分析是横向并购反垄断审查的重点。20世纪90年代以后．为了弥补传统结构主义分析方法的不足，欧美国家反垄断当局开始将模拟分析技术引入并购评估审查。然而，并购单边效应模拟分析中存在模型复杂度与可操作性之间的矛盾。为了降低模型复杂度并保持模型解释力。本文在PCAIDS模型的基础上改变加总性假设．引入零次齐次性假设．构建了H—PCAIDS模型．并通过矩阵变换推导了用于估计双产品市场需求系统的简化版H—PCAIDS模型；然后，使用以上两类模型分别估计了中国电冰箱行业的需求系统．利用估计得到的需求参数评估了中国电冰箱行业横向并购的单边效应。实证分析结果表明．横向并购单边效应的大小取决于产品之间的替代程度、转移率、产品的市场份额．以及效率改进的程度；H—PCAIDS模型能够从两个维度降低横向并购单边效应模拟分析的难度．所需估计的需求参数减少，数据要求的严苛程度下降，易于操作，并且具有较高的精确性和解释力，能够在较短时限内为并购评估审查提供量化证据和决策依据。

英文摘要：

Horizontal mergers may have anti-competitive effects including unilateral effects and coordinated effects, and of the two, the evaluation and the analysis of the unilateral effect is prior in the antitrust scrutiny of horizontal mergers. The antitrust authorities in the Europe and America have introduced merger simulation technology into the evaluation and analysis of mergers to compensate the deficiency of the traditional structuralism analysis since 1990s. However, the model complexity conflicts with the operability in the merger simulation analysis of the unilateral effects. In order to reduce the model complexity and guarantee the explanatory power at the same time, the paper alters the aggregation assumptions on the basis of the PCAIDS model, introduces the homogeneity of degree zero assumption, so as to constructs the H-PCAIDS model, and deduces the simplified version of H- PCAIDS model which is used to estimate the system of the demand of a double-product market through the matrix transformation. And then, the paper estimates the demand system of China＇s refrigerator industry respectively with the two above models, evaluates the unilateral effects of horizontal mergers in the refrigerator industry of China utilizing the demand parameters accessed by the preceding evaluation, and analyzes the impacts that the product substitution, market share and efficiency exert on the unilateral effects. Empirical resuhs show that the H-PCAIDS model reduces the difficulty of simulation analysis on the unilateral effects of horizontal mergers from two dimensions by decreasing the number of demand parameters to he estimated and the rigid degree of data requirement. And also at the same time the H-PCAIDS model is easier to operate with a certain degree of accuracy and explanatory power so as to provide quantitative evidence and decision-making basis for the evaluation and scrutiny of the mergers within a short time.