기업의 ESG 활동은 내재자기자본비용을 낮추는가? : 서스틴베스트데이터를 이용한 분석

[Purpose] This study examines whether changes in corporate ESG (Environment, Social, Governance) performance act as an economic incentive by reducing the implied cost of equity capital. This research differentiates itself by providing empirical evidence using Sustinvest ESG scores, which have been relatively unexplored in prior literature. [Method] We conduct a multiple regression analysis on a sample of 1,717 firm－year observations from Korean listed firms for the period 2014－2022. The dependent variable is the implied cost of equity capital (ICoE), estimated using the PEG model. The independent variables are the changes in Sustinvest's ESG scores, measured as both continuous variables and dummy variables. [Results] The findings indicate that an improvement in the composite ESG score is significantly negatively associated with the implied cost of equity capital. This effect is predominantly driven by improvements in the Governance (G) score, while the standalone effects of the Environment (E) and Social (S) scores are statistically insignificant. [Implications] Our results confirm that investors in the Korean capital market perceive improvements in Governance (G)－which are directly linked to managerial transparency and shareholder protection－as a key risk－mitigation factor. This implies that ESG is not merely a cost but can serve as a financial incentive by lowering the implied cost of capital. The findings also suggest the need for a differentiated policy approach to ESG disclosure.