Firms’ voluntary climate action disclosures and stock market reaction: A BERT-based analysis of earnings conference calls in China

Climate information disclosure plays a pivotal role in fostering sustainable practices and enhancing transparency in climate risk. However, it is unclear whether firms’ voluntary climate-related disclosures effectively convey incremental information to investors. In the empirical context of Chinese listed firms, we explore the valuation effect of firms’ voluntary climate action disclosures, which is quantified from the transcripts of earning conference calls using a novel natural language model, BERT. Our results reveal that firms with more voluntary climate action disclosures experience more positive stock market reactions, indicating that investors value transparency on corporate commitment to future climate actions. The positive valuation effect of disclosures tends to be more pronounced in firms with higher disclosure quality, more green-preference investors, and higher investor attention. Moreover, we find that the positive valuation effect is achieved through enhancing corporate reputation and investor confidence. We further show that firms’ voluntary climate action disclosures exhibit a significant positive correlation with green innovations and environmental pillar scores, dispelling concerns of mere “greenwashing”. Overall, our evidence contributes to understanding the role of climate disclosures in investor assessment of firms’ climate risks and opportunities. The findings provides fresh insights for policymakers and regulatory bodies involved in shaping disclosure frameworks that promote sustainable business practices.