IFRS 18과 K－IFRS 영업손익의 이익의 질 비교：이익지속성과 변동성을 중심으로

[Purpose]This study examines the impact of the newly defined operating profit under IFRS 18 Presentation and Disclosure in Financial Statements, which will become mandatory in 2027, on the quality of earnings. [Methodology]Using 21,197 firm－year observations of non－financial companies listed on the KOSPI and KOSDAQ markets from 2012 to 2023, this study reconstructs IFRS 18－based operating profit from disclosed financial statement items and constructs a comparable panel dataset with K－IFRS operating profit. Earnings persistence is measured as the coefficient from regressions of current operating profit on future operating profit, and differences between the two reporting regimes are tested using pooled regressions and Wald tests. Earnings volatility is computed as the firm－level time－series standard deviation of operating profit, and differences in volatility are evaluated through regression analysis. [Findings]The empirical results show that K－IFRS operating profit exhibits significantly higher earnings persistence than IFRS 18 operating profit. Second, earnings volatility under IFRS 18 is significantly higher than under K－IFRS. These findings suggest that K－IFRS operating profit provides higher－quality information from an earnings－quality perspective. [Implications]This study offers early empirical evidence on how the redefinition of operating profit under IFRS 18 affects earnings quality. Our findings suggest that IFRS 18 may reduce the predictability and stability of reported operating performance. Practically, the results highlight the need for analysts and investors to distinguish between recurring and non－recurring components when interpreting IFRS 18 operating profit, and suggest that managers should strengthen voluntary disclosures to mitigate concerns about increased earnings volatility.