사업보고서의 가독성이 외부감사인 현장감사 상주인원 비율에 미치는 영향

This paper investigates how the readability of annual reports affects the ratio of resident auditors during on-site audits. While prior studies have increasingly applied text mining and natural language processing techniques to corporate disclosures, most have focused on English-language reports, leaving research on Korean-language annual reports relatively scarce. The readability of annual reports can influence the efficiency of auditor–client communication, thereby affecting auditors’ staffing decisions during on-site audits. When annual reports are less readable, information processing costs increase, potentially requiring auditors to allocate more resident personnel to assess reporting risks and ensure audit quality. Proxying for annual report readability using three commonly adopted measures in the accounting literature—the Flesch Reading Ease Score, the Gunning Fog Index, and the natural log of total word count (Length)—we construct a composite indicator that reflects document Length, sentence structure, and lexical complexity. The sample consists of KOSPI- and KOSDAQ-listed firms from 2014 to 2021. The ratio of resident auditors is hand-collected from the “Main Details of On-Site Audit” section in audit reports attached to annual reports filed with the Financial Supervisory Service’s DART system. Empirical results show that all three readability measures are significantly and negatively associated with the resident auditor ratio, indicating that less(more) readable annual reports are followed by higher(lower) proportions of resident auditors. This relationship holds consistently across the pre–COVID-19 (2014–2019) and post–COVID-19 (2020–2021) subsamples, suggesting that the clarity of disclosure remains a key determinant of on-site staffing even during pandemic-related constraints. Analyses using year-over-year changes in readability yield consistent results, and interaction tests reveal stronger effects for audits conducted by Big 4 firms and for firms with stronger corporate governance. This study shows that the readability of annual reports goes beyond the quality of disclosure itself and serves as a critical factor influencing auditors’ resource allocation and audit efficiency. Unlike prior studies on audit effort that primarily use audit hours as a proxy, this study distinguishes itself by utilizing the legally disclosed information in audit reports regarding the number of headcount involved — specifically, the number of resident and non-resident auditors — to measure audit effort in terms of on-site deployment structure and qualitative aspects. It provides empirical evidence that the linguistic characteristics of disclosure documents are not confined to investors’ information use but are also reflected in auditors’ practical decisions, such as the allocation of on-site personnel. In other words, enhancing the clarity of corporate disclosures can reduce the burden and costs of audit responses for firms, enable more efficient resource allocation for auditors, and serve as a policy instrument for regulators to improve audit quality and market efficiency.