The OTM emphasizes the importance ofdata triangulationin ESG integration, noting the variability and inconsistency among ESG data providers. It states:

“Asset managers should seek tocorroborate ESG data across multiple independent sourcesto mitigate bias, data gaps, and methodological divergence.”

It adds that while audited ESG data are preferred, much of the information remains self-reported or estimated; thus, verification through comparison of multiple datasets (e.g., MSCI, Sustainalytics, Refinitiv) improves reliability.

The manual warns that relying solely on a single provider can lead to “material misrepresentation of risk exposure or sustainability performance.” Option C (multi-decade backtesting) is rarely feasible due to limited historical ESG data. Hence, optionBis the best verified practice consistent with professional ESG integration standards.

????Reference:2021-Final-Book.pdf, Chapter 7 — ESG Data Quality and Integration (Triangulation and Validation Techniques section).