We develop a model of vertical merger waves and use it to study the optimal merger policy. As a merger wave can result in partial foreclosure, it can be optimal to ban a vertical merger that eliminates the last unintegrated upstream firm. Such a merger is more likely to worsen market performance when the number of downstream firms is large relative to the number of upstream firms, and when upstream contracts are non‐discriminatory, linear and public. On the other hand, the optimal merger policy can be non‐monotonic in the strength of synergies or in the degree of downstream product differentiation.

中文翻译：

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反竞争垂直合并波

我们建立了垂直合并浪潮的模型，并用它来研究最优合并政策。由于合并浪潮可能导致部分丧失抵押品赎回权，因此最好是禁止进行纵向合并，以消除最后一家未整合的上游公司。当下游公司的数量相对于上游公司的数量较大，并且上游合同是非歧视性，线性和公开的合同时，这种合并更有可能使市场表现恶化。另一方面，最优合并政策在协同作用方面或下游产品差异化程度上可以是非单调的。