对外担保与股价同步性

External Guarantees and Stock Price Synchronization

本文以2010-2022年沪深A股上市公司为样本研究发现,上市公司对外担保与股价同步性显著正相关;同时,对外担保对股价同步性的提升作用在非国有企业、两权分离度高、法律环境较差的组别中更加显著。影响机制检验显示:对外担保通过降低企业信息透明度,进而提升了股价同步性。进一步研究发现,相较非子公司,对子公司提供担保更能提升股价同步性。本文的研究结论为我国股价“同涨同跌”的现象提供了理论解释,也为企业完善经营和改善资本市场信息效率提供了有益启示。

Based on the data of Shanghai and Shenzhen A-share listed companies from 2010 to 2022,it is found that there is a significant positive correlation between the external guarantee and the stock price synchronization.Moreover,the promotion effect of the former on the latter is more significant in non-state-owned enterprises or in groups with higher degree of separation between ownership and control or in those with poor legal environment.The impact mechanism test shows that the former can improve the latter by reducing the transparency of corporate information.Further research finds that a guarantee provided to a subsidiary can better enhance the stock price synchronization than that to a non-subsidiary.This result provides a theoretical explanation for the“in-lockstep rise and fall”of China's stock prices,and also inspires enterprises to improve their management and information efficiency in the capital market.