ABSTRACT In 2014, the PCAOB adopted a new auditing standard, AS 18 Related Parties, with the intention of enhancing auditors’ performance in auditing related-party transactions (RPTs). Using hand-collected data, we find significant reductions in both firms’ restatement risk and their engagement in RPTs following the AS 18 adoption. Such reductions are especially pronounced for smaller firms and firms having RPTs with principals, in which related persons in the counterparty of RPTs are the primary beneficiaries, such as CEOs, board chairs, or primary shareholders. We also find that smaller firms having RPTs with principals tend to pay higher audit fees post-AS 18. Our study responds to the PCAOB’s call to assess the economic consequences of AS 18. The findings suggest that AS 18 is associated with improved audit quality and reductions in auditees’ opportunistic RPT activities. Data Availability: Data are available from public sources as cited in the article and from the authors upon request. JEL Classifications: M10; M40; M41; M42; M48.

ABSTRACT This study investigates whether companies engage in audit opinion shopping activities by exerting influence over an audit firm's decision to switch the engagement partner (“partner‐level opinion shopping”) in the Chinese setting, where the identities of engagement partners are publicly disclosed. Adopting the empirical framework developed by Lennox [2000], we show evidence that companies successfully engage in partner‐level opinion shopping. Further, partner‐level opinion shopping is more likely to be successful if a company is economically important to an audit firm, and it is less likely to be successful if the audit firm is formed as a partnership rather than a corporation. We also find that companies successfully engaging in partner‐level opinion shopping exhibit significantly lower earnings quality. Finally, we directly compare audit records between incoming and outgoing partners and find that, for companies that successfully improve audit opinions after partner switching, incoming partners have a significantly higher propensity to issue clean opinions than their outgoing counterparts.