The main purpose of this study is to investigate the effect of investor sentiment on accounting conservatism in listed companies in the Tehran Stock Exchange (TSE).

In this paper, two models of Ball and Shivakumar (2006) and Basu (1997) have been used for measuring conditional conservatism in accounting. To measure investor sentiment, the author uses the Baker and Wurgler (2006, 2007) index. The research sample consists of 1,820 observations and 182 firms listed on TSE over a ten-year period between 2011 and 2020. This study uses panel data and multivariate regression analysis to test it hypotheses.

Consistent with this hypothesis that accounting conservatism will increase with investor sentiment, the results showed that Iranian firms recognize economic losses and bad news in a more timely manner during high sentiment periods than during low sentiment periods. This implies that Iranian managers recognize economic losses and bad news in earnings in a more timely manner during periods of high investor sentiment.

This finding provides significant evidence for investors and financial reporting standard-setters in Iran because by removing accounting conservatism from the conceptual framework, managers are not able to present conservative financial reports, and this can intensify the negative impact of investors sentiment in the Iranian capital market. Managers of Iranian companies can reduce information asymmetry and increase capital market efficiency by accelerating the disclosure of bad news. Thus, managers can strategically recognize losses and prevent investors from making emotional decisions that reduce their wealth.

To the best of the authors’ knowledge, this is the first study to empirically examine the impact of investor sentiment on accounting conservatism in a developing market called Iran. This study contributes to the corporate disclosure literature. Also, the result of this study contributes to standard-setters of accounting standards to improve the mandatory disclosure literature on more conservative accounting earnings.