Mandatory IFRS Adoption and Financial Statement Comparability
Executive Summary — In the past decade, many countries have adopted International Financial Reporting Standards (IFRS) developed by the International Accounting Standards Board, which has impelled economists to examine the benefits of the standards. This paper discusses how IFRS adoption affects financial reporting comparability—that is, the properties of financial statements that allow users to identify similarities or differences between the economics of different reporting entities over any given period of time. Research was conducted by Francois Brochet and Edward J. Riedl of Harvard Business School, and Alan Jagolinzer of the University of Colorado at Boulder. Key concepts include:
- Mandatory IFRS adoption results in a reduction of abnormal returns to insider purchases.
- IFRS adoption also results in a reduction of abnormal returns to analyst recommendation upgrades.
- These improvements can also accrue in settings in which information quality is already high, and incumbent domestic standards are already similar to IFRS.
- All results are consistent with IFRS adoption improving financial statement comparability.
This study examines the effect of mandatory International Financial Reporting Standards (IFRS) adoption on financial statement comparability. To isolate the effects of changes in comparability, we examine changes to information asymmetry for firms domiciled in the UK. UK domestic standards that preceded IFRS adoption are considered very similar to IFRS (Bae et al. 2008); accordingly, we use the UK as a setting to isolate changes to the information environment relating to IFRS adoption that more likely to reflect changes in comparability versus information quality. If IFRS adoption improves financial statement comparability across firms, we predict this should reduce private information benefits. Empirical results confirm these predictions. Specifically, abnormal returns to two proxies for private information (insider purchases and analyst recommendation upgrades) are reduced following IFRS adoption. Similar results are obtained for subsamples that further isolate the reduction in private information as attributable to increases in comparability: firms having low amounts of reconciling items between UK GAAP and IFRS, and firms having ex ante high quality information environments. Together, the results are consistent with mandatory IFRS adoption leading to enhanced comparability.