Is History Repeating Itself? The (Un)predictable Past of ESG Ratings

Is History Repeating Itself? The (Un)predictable Past of ESG Ratings

Florian Berg, Kornelia Fabisik, Zacharias Sautner

Series number :

Serial Number: 
708/2020

Date posted :

November 10 2020

Last revised :

September 02 2021
SSRN Share

Keywords

  • ESG ratings • 
  • ESG investment • 
  • CSR

The explosion in ESG research has led to a strong reliance on ESG rating providers. We document widespread changes to the historical ratings of a key rating provider, Refinitiv ESG (formerly ASSET4). Depending on whether the original or rewritten data are used, ESG-based classifications of firms into ESG quantiles and tests that relate ESG scores to returns change.

While there is a positive link between ESG scores and firms’ stock market performance in the rewritten data, we fail to observe such a relationship in the initial data. The ESG data rewriting is an ongoing rather than a one-off phenomenon.

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Authors

Dr.
Real name:
Florian Berg
MIT Sloan School of Management