We examine whether bank connections via common mutual fund ownership serve as a contagion channel affecting the systemic risk of the banking system. Examining this relation is important because common mutual fund ownership has increased dramatically over the past 20 years, and a buildup of systemic risk was at the heart of the 2008–2009 financial crisis. We predict and document that the extent of a bank's connection with other banks via common ownership increases its contribution to systemic risk. We further predict and find that this association is primarily driven by passive mutual funds. We provide evidence that common passive ownership results in higher systemic risk through two mechanisms: nondiscretionary sell-offs of bank stocks and a common pattern of voting. Our results are also robust to two alternate instrumental variable analyses. This study contributes to the literature by documenting an unintended, macro-level consequence of common mutual fund ownership. Our findings broaden the understanding of common ownership as one mechanism through which systemic risk materializes and should be particularly relevant for regulators who seek to prevent future systemic failures.

中文翻译：

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共同基金所有权和系统性风险*

我们研究了通过共同基金所有权的银行联系是否成为影响银行系统系统性风险的传染渠道。研究这种关系很重要，因为过去 20 年来共同基金的所有权急剧增加，而系统性风险的积累是 2008-2009 年金融危机的核心。我们预测并记录了银行通过共同所有权与其他银行的联系程度增加了其对系统性风险的贡献。我们进一步预测并发现这种关联主要是由被动共同基金驱动的。我们提供证据表明，共同被动所有权通过两种机制导致更高的系统风险：银行股票的非全权抛售和共同的投票模式。我们的结果对于两个替代的工具变量分析也是稳健的。本研究通过记录共同基金所有权的意外宏观后果为文献做出贡献。我们的研究结果拓宽了对共同所有权作为系统性风险实现的一种机制的理解，并且应该与寻求防止未来系统性故障的监管机构特别相关。