ESG investing in the Eurozone : Portfolio performance of best-effort and best-in-class approaches

Abstract: The last decades have seen a rapid increase of sustainable investing, also known as ESG (Environmental, Social and Governance) investing. There has also been an increasing body of academic literature devoted to whether investors can gain any financial benefits from taking ESG under consideration. Previous literature of portfolio performance in terms of risk-adjusted returns has given much of its attention to best-in-class approaches, which is a strategy that selects top performers in ESG within a sector or industry. The purpose of this study is foremost to investigate a best-effort approach to ESG investing, which is a strategy that focuses on the top improvers in ESG. The purpose is further to compare this with a best-in-class approach, since the findings from earlier studies of this strategy still are inconsistent. The region chosen to perform this study in is the Eurozone. Several theories that have implications for portfolio studies and abnormal returns are taken under consideration in relation to the study and its findings. This includes the efficient market hypothesis, the adaptive market hypothesis and modern portfolio theory. The theoretical framework also cover asset-pricing models and the notions of risk-adjusted returns. A quantitative study with a deductive approach are used to form portfolios, with a Eurozone index as the investable universe. Best-effort and best-in-class portfolios as well as difference portfolios of the two approaches are created, based on ESG data and different cut-off rates for portfolio inclusion. As for risk-adjusted performance measure, the Carhart four-factor model are used. The overall results are mostly insignificant findings in terms of abnormal returns. However, three best-effort portfolios based on the top ESG improvers show significant positive abnormal returns. These findings are strongest for the environmental and social factor. As for the best-in-class approach, only the governance portfolios provided weakly significant results in terms of abnormal returns. Further, the study is not able to significantly distinguish between a best-effort and a best-in-class approach when it comes to risk-adjusted performance. The exception is the environmental factor based on the top performers in each approach, where the best-effort portfolio outperforms the best-in-class portfolio. Finally, none of the portfolios provided significant negative risk-adjusted returns. This can at least be considered as good news for ESG investing, since it indicates that investors do not have to sacrifice risk-adjusted returns in order to invest in a more sustainable way.