As investors, corporations, and regulators place greater importance on ESG-related matters, it’s worth understanding which ESG information has the most significant impact on markets. Attempting to address this question, George Serafeim, Charles M. Williams professor of business administration at Harvard Business School, and Aaron Yoon, assistant professor of accounting information and management at the Kellogg School of Management, conducted a study on the effect of ESG-related news on companies’ stock prices.

Enhancing prior research on ESG-related matters, Serafeim and Yoon took a systemic and technology-focused approach by utilizing natural language processing, eliminating selection bias that is present when humans subjectively analyze data. The data source for this research was FactSet TruValue Labs (“TVL”), which tracks daily ESG-related information across thousands of companies and classifies this news as positive or negative. TVL uses artificial intelligence to pull and analyze ESG news from analyst reports, media, and government regulators. Using TVL, Serafeim and Yoon’s research included 109,014 pieces of ESG-related news across 3,109 U.S. companies.

During their research, Serafeim and Yoon concluded it’s unclear whether ESG scores will predict future ESG news because investors may disregard ESG scores. Additionally, Serafeim and Yoon agree with previously published research in that negative ESG news results in adverse equity price reaction, and conversely, positive ESG news produces positive stock price movements. However, Serafeim and Yoon take it one step further, clarifying that the position stock price reaction to positive ESG news is stronger than the negative equity price movement in response to negative ESG news.

In conclusion, Serafeim and Yoon found that companies’ stock prices reacted most to ESG-related news that was unexpected, positive, and material. Furthermore, ESG news that received more coverage and related to social capital issues had a more significant impact on equity prices. For example, on the day positive news was released about product safety, equity prices correspondingly moved 1.55% on average that same day.