We empirically test competing theoretical arguments about the impact of common ownership on bank stability: the common ownership hypothesis, where banks decrease risk-taking by internalizing risk externalities on commonly held banks, and the diversification hypothesis, where banks increase risk-taking influenced by common owners who hold diversified portfolios and are less risk averse. Using data from the U.S. banking industry from 1991 to 2016, we find that banks with more common ownership linkages undertake lower risk, as predicted by the common ownership hypothesis. This relation is statistically significant and economically sizable, which is consistent across alternative measures of common ownership and bank risk and robust to potential endogeneity. Our study adds the financial stability perspective to the ongoing discussions on common ownership and antitrust regulations.

我们以经验方式检验有关普通所有权对银行稳定性的竞争性理论争论：普通所有权假设，即通过将普通持有银行的风险外部性内部化来降低风险承担的普通所有权假设；以及多元化假设，银行在拥有多元化投资组合且对风险的规避程度较小的共同所有者的影响下，提高了冒险精神。使用1991年至2016年美国银行业的数据，我们发现，拥有更多共同所有权链接的银行承担的风险更低，这是由共同拥有权假设所预测的。这种关系具有统计意义，并且在经济上相当可观，在具有共同所有权和银行风险的替代措施之间保持一致，并且对潜在的内生性具有鲁棒性。我们的研究将财务稳定性的观点添加到了有关共同所有权和反托拉斯法规的持续讨论中。