讲座报告主题：Multimarket Contact and Platform Competition: Reassessing the Mutual Forbearance Hypothesis
专家姓名：Thomas LE TEXIER
主讲概况：法国雷恩第一大学经济学院副教授，2008年获法国尼斯大学（University of Nice–Sophia Antipolis）博士学位。Thomas副教授主要研究领域为基于管理与市场方面的创新及数字经济学。他近年来的研究兴趣集中在通过理论研究的方法探索多边市场产业组织及相关数字服务（竞争策略及规制方向）。目前开展的一项研究为探索数字产业内人工智能技术及算法的扩散以及对市场价格及政策规制的影响。
主讲内容：Antitrust authorities are particularly concerned with the dominant market positions of Tech giants like GAFA or BATX. These winner-take-all companies are characterized by platform-based business models. However despite their dominant positions, they are competing with each other to attract the same groups of users (developers, advertisers, end users, third party sellers ...). They have not only overlapping users (or sides) but also multi-market contact. With traditional (one-sided) markets, theory and empirical evidence show that multimarket contact tends to relax competition (i.e. facilitate collusion). But it is unclear whether this mutual forbearance hypothesis holds under platform competition. This paper examines how multimarket contact can affect pricing behavior and profits of two-sided platforms. We develop a model in which platforms only charge one side (and provide free access to the other side). MMC generate cross-market externality that benefits one side of the platform. We show that when externality benefits the side that does not pay, price competition is fiercer and welfare increases under MCC. When cross-market externality benefits the side that pays, the same result holds only if cross-group externality and/or cross-market externality are sufficiently high. Finally, we show that a single-market platform competing with a multimarket platform has no incentive to become a multimarket platform if cross-market and cross-group externality are high. Our findings contrast with the mutual forbearance hypothesis that claims that MMC relax competition in traditional industries. From a competition policy perspective, antitrust authorities should not be too worried about dominant platforms that develop multi-market strategies (for instance through mergers and acquisitions of complementary platforms), especially if cross-market externality benefits mostly to the non-paying users.