Legal infrastructure construction and audit opinion: Evidence from the implementation of China's new securities law

• The implementation of NSL can affect auditors’ behavior of issuing audit opinion . • Audit market concentration and disciplinary risks are core mechanism approaches. • Stock exchange inquiry and CICPA interview can generate synergistic effects. Based on the background of the implementation of China's New Securities Law (NSL) and the data of Chinese listed enterprises from 2016 to 2023, this paper investigates the influence of the new-updated legal infrastructure construction on auditors’ behavior of issuing audit opinion. The findings depict that the implementation of NSL can significantly improve the possibility of issuing non-standard audit opinion by auditors. Mechanism tests confirm that reducing audit market concentration and increasing disciplinary risks are core mechanism approaches. Further discussion reveals that the incentive effect of NSL implementation on the possibility of issuing non-standard audit opinion is more prominent under the synergy of both the stock exchange inquiry and the scrutiny action of the CICPA interview. This paper makes practical implications for standardizing auditors’ behavior, improving the quality of audit verification responsibility, and consequently protecting the legitimate rights of investors.