Global ESG transformation is unfolding in the conditions of institutional asymmetry across economies. This lack of balance hinders effective planning and development of international cooperation and business practices necessary to achieve sustainability principles. This article aims to identify the mechanisms through which institutional investors influence corporate ESG practices in countries with a “Very High” Human Development Index (HDI) and in the BRICS nations. A comparative analysis of five regulatory instruments (mandatory ESG disclosure, national taxonomy, carbon regulation, ESG requirements for pension funds, and sovereign green bonds) revealed qualitative differences in the channels of influence: direct impact through corporate governance mechanisms in countries with highly developed social institutions (institutional investor share 30–70%, GRI standards adoption 89%) versus indirect influence through access to international capital in BRICS countries (institutional investor share <15–30%, GRI adoption 34%). The analysis of regulatory instruments identified substantial differences between the two country groups: a comprehensive ESG regulatory framework in countries with a very high HDI contrasts with the fragmented implementation of individual instruments in BRICS economies. Expert interviews (n = 30) confirm differences in integration drivers: regulatory pressure and investor requirements dominate in high-HDI countries (87% and 80% of mentions, respectively), whereas access to international capital serves as the primary driver in BRICS countries (73% of mentions). These results allow the authors to formulate differentiated recommendations for improving the effectiveness of achieving sustainability principles. These recommendations consider the identified characteristics of countries with underdeveloped social institutions and their institutional constraints.
