This study takes the merger and acquisition (M&A) events completed by A-share listed companies in Shanghai and Shenzhen stock markets from 2006 to 2019 as the research samples and uses the dual difference method to test the impact of a “high-speed railway (HSR) opening”, a quasi-natural experimental event, on M&A premium. The results show that the opening of an HSR can significantly inhibit the M&A premium of listed companies in corresponding prefecture-level administrative regions. The results of the mechanism test show that an HSR opening affects M&A premium through two channels: “reducing information asymmetry” and “alleviating agency problems”. This study discusses the impact of an HSR opening on M&A, which helps to provide new empirical evidence for the economic consequences of an HSR opening from the micro level and provides a new perspective for research on the factors affecting M&A premium.

As the biggest black swan event of 2020, the COVID-19 pandemic has significantly weakened the ability of corporate stakeholders to monitor companies on site. In this context, exploring whether the on-site supervision restrictions triggered by the COVID-19 pandemic affect management earnings forecast disclosure is crucial to protect investors' interests and promote the stable development of the capital market. Based on quarterly data of Chinese A-share listed companies' earnings forecasts, this paper finds that: First, when the company's registry region is more severely affected by the COVID-19 pandemic, the company has less willingness to disclose its management earnings forecast. And those released forecasts tend to have lower qualities. Second, a higher level of media monitoring and a better legal environment can mitigate the negative impacts of the COVID-19 pandemic on both the willingness and the quality of management earnings forecast disclosure. Furthermore, mediating effect analysis shows that, the reduced on-site monitoring activities that were originally implemented by independent directors, institutional investors, and analysts during the epidemic period greatly limited stakeholders' monitoring efficiency, and thus cause significant influence on the disclosure of management earnings forecasts.