Auditor Choice and the Informativeness of 10-K Reports
研究发现客户选择四大审计师（普华永道、安永、毕马威、德勤）能增加10-K年报的披露篇幅，且这种增强效应在应计质量差、信息不对称高的客户中更明显；还提出用10-K长度中无法被经营复杂度解释的部分作为审计努力的新代理变量。
This study provides new evidence on the influential role of external auditors in enhancing the informativeness of form 10-K annual reports to shareholders. Specifically, we find that the client's choice of a Big 4 auditor (PwC, EY, KPMG, and Deloitte) versus a non-Big 4 auditor contributes to cross-sectional variations in 10-K disclosure volume. We also document that the benefit of enhanced disclosures provided by Big 4 auditors is more pronounced for audit clients with poorer accrual quality and those with higher information asymmetry. Furthermore, we introduce the portion of 10-K length unexplained by operating complexity and observable client characteristics as a new proxy for audit firm effort. Specifically, we find that abnormally long disclosures are associated with higher audit fees and longer audit report lag, which implies that an incremental level of audit effort can be inferred from the discretionary component of 10-K disclosures. As audit effort is costly, a greater volume of 10-K disclosures can be expected to be associated with an improvement in the quality of financial reporting. Overall, our findings show that auditors play more than a simple attestation role in the financial reporting process, and that the quality of financial reporting in a company's 10-K annual report is a joint product of the effort and decisions of both a company's managers and its auditors.