Corporate social responsibility as a common risk factor

This article challenges factor models widely used to explain stock returns. For European firms involved in corporate social responsibility (CSR) actions, we find a risk premium associated with extra-financial ratings priced by the market (that is, environmental, social, and governance ESG] ratings). This premium is calculated as the excess return of low-rated firms compared to high-rated firms. To describe rated firms' returns, we propose a parsimonious two-factor model that includes both the market factor and this premium. Unlike the CAPM, three-, or five-factor models, our model is validated by the Gibbons, Ross and Shanken (1989) test. Our results lead to many managerial implications related to portfolio management, asset pricing, and corporate financial and investing decisions.