Abstract

This study investigates how voluntary International Financial Reporting Standards (IFRS) adoption impacts information asymmetry in the stock market. We analyze data from firms in Japan, where local accounting standards have substantially converged with IFRS but are more rules-based than principles-based IFRS. These different implementation approaches allow us to investigate how increased accounting flexibility influences recognition and measurement practices, attenuating the effects of accounting standard differences on the level of accounting rule existence or non-existence. We find that information asymmetry increases after voluntary IFRS adoption, which is driven by small- and medium-sized IFRS adopters’ decrease in earnings quality after voluntary IFRS adoption. Additional analyses reveal that firms’ reporting incentives and accounting resources influence these changes. These results suggest that IFRS’s increased accounting flexibility in recognition and measurement practices worsens the information environments of firms with weak incentives to commit to transparent financial reporting or fewer accounting resources (i.e., small- and medium-sized firms).

Introduction

As International Financial Reporting Standards (IFRS) are intended to provide investors with information that enables them to make better investment decisions, information asymmetry in stock markets is a critical potential consequence of IFRS adoption. IFRS adoption worldwide is either voluntary or mandatory. Since the 2005 mandatory adoption for firms listed in EU countries, extensive research has been conducted on the effects of mandatory IFRS adoption. However, voluntary IFRS adoption effects are relatively under-researched, especially in recent years (De George et al., 2016, Leuz and Wysocki, 2016). Understanding the effects of voluntary adoption is also important because a non-trivial number of countries either allow voluntary IFRS adoption or prohibit IFRS adoption (Song and Trimble, 2022). As of 2019, 11 % (22) of 195 countries/territories permit IFRS adoption and 6 % (11) presently prohibit it, although the latter could permit voluntary adoption in the future. This study attempts to further our understanding of how voluntary IFRS adoption affects information asymmetry in stock markets.

Prior research provides mixed evidence on the stock market consequences of voluntary IFRS adoption. Early studies on this topic focus on Germany, where local accounting standards are substantially different from IFRS. These studies provide evidence suggesting that voluntary adopters exhibit lower information asymmetry in the stock market compared to non-adopters (Gassen and Sellhorn, 2006, Leuz and Verrecchia, 2000). However, in international comparisons, Daske et al. (2008) use two proxies for differences between local accounting standards and IFRS and report inconsistent liquidity effect results. Specifically, they observe no change in liquidity after voluntary IFRS adoption in countries with small differences between local generally accepted accounting principles (GAAP) and IFRS, but a decrease in liquidity in countries with IFRS convergence processes. Therefore, how voluntary IFRS adoption affects information asymmetry in stock markets in countries whose accounting standard differences from IFRS are relatively small remains unclear. This study aims to extend this line of research.

Conclusions

Prior research suggests that voluntary IFRS adoption positively affects information asymmetry in stock markets when local accounting standards significantly differ from IFRS and is viewed as a commitment to transparent financial reporting. However, other research obtains inconsistent results for voluntary IFRS adoption effects on information asymmetry in countries with small accounting differences between local standards and IFRS. We looked closer at Japan, where local accounting standards have been converged to IFRS but have a different implementation approach (i.e., small accounting rule differences but large implementation approach differences). We investigated the effect of voluntary IFRS adoption on the stock market (i.e., changes in information asymmetry in the stock market proxied by bid-ask spread) as well as its potential reason (i.e., changes in earnings quality proxied by the absolute value of discretionary accruals). We also examined whether this effect varies according to firm size, which represents firms’ reporting incentives and accounting resources. Our study’s findings and incremental contributions to the literature are as follows.

First, we find an increase in the bid-ask spread after voluntary IFRS adoption. This result suggests that, on average, voluntary IFRS adoption worsens information asymmetry in Japan’s stock markets. Second, we observe deterioration in bid-ask spread only for smalland medium-sized voluntary adopters. Third, we examine changes in IFRS adopters’ earnings quality before and after IFRS adoption to explore a reason for the increased bid-ask spread. We find that small- and medium-sized firms report larger discretionary accruals after voluntary IFRS adoption. These results suggest that the increase in information asymmetry in the stock market results, at least partially, from the decreased earnings quality of small- and medium-sized firms after voluntary IFRS adoption. Finally, we provide some evidence suggesting that firms’ reporting incentives and limited accounting resources deteriorate earnings quality and information asymmetry at the time of voluntary IFRS adoption.