Exploring the impact of auditor industry specialization on income smoothing

Since the late 1970s' reform and opening-up, China's economy has achieved remarkable success, maintaining an average annual GDP growth of 9.7% from 1978 to 2006. In 2007, China achieved a GDP of 3.38 trillion USD, surpassing Germany to become the world's third-largest economy, and by the second quarter of 2010, it had become the second-largest economy globally. These developments have attracted international investors' attention to Chinese equities. However, China's poor reputation for corporate governance may deter investors, despite their positive outlook on China's economy. Corporate managers in China are known to engage in income smoothing, taking actions to dampen fluctuations in their firms' publicly reported net income. In 2004, the OECD proposed that a strong disclosure regime promoting real transparency can help attract capital and maintain confidence in the capital market, with income smoothing being a key concern for both institutional and individual investors. This study investigates how auditor industry specialization (AIS) affects income smoothing behavior in Chinese listed companies. Using a sample of 27,208 firm-year observations from 2006 to 2018 collected from the Taiwan Economic Journal Database, the results indicate that AIS is negatively related to managers' income smoothing behavior, underscoring the importance of industry expertise in mitigating such practices. Additionally, an independent t-test highlights the difference between Big Four and non-Big Four auditors in influencing client companies' income smoothing behaviors. The study further demonstrates the significant moderating effect of Big Four auditors on the relationship between accounting firms with top industry expertise and client companies' income smoothing, reflecting the unique characteristics of the Chinese market. This study verifies the suppressive effect of AIS on firms' income smoothing and indirectly suggests that governments (or the Chinese Institute of Certified Public Accountants, CICPA) should regularly disclose accounting firms/auditors with industry expertise publicly. This regime can help global investors make informed investment decisions.