ESG Investing: Can You Have Your Cake and Eat It Too?
Can you have your cake and eat it too?
The ongoing debate about environmental, social, and governance (ESG) investing sometimes feels like a rehash of that age-old rhetorical question.
Proponents of ESG data believe it can help investors better understand the risks and opportunities companies face and may even offer alpha generation potential. On the other hand, skeptics think ESG criteria limit the universe of available stocks and that such restrictions are bound to negatively impact returns.
To return to our metaphor, having the ESG cake means generating strong investment performance, while eating it too implies doing good from an ESG perspective.
So which is it? Can investors have it all?
To answer this, we analyzed Refinitiv’s ESG database, which covers more than 7,000 public companies across the globe. Refinitiv generates ESG scores for each firm based on 178 data points. Companies are ranked on a 100-point scale relative to their peers, with a composite ESG score as well as separate category scores for environment, social, and governance, individually. The higher the score, the better the ESG ranking.
We divided the historical ESG ratings of all S&P 500 firms into four categories: Those with scores of 76 or above are labeled “Excellent”; between 51 and 75 are “Good”; between 26 and 50 are “Fair”; and 25 and below are “Poor.”
S&P 500 Holdings by ESG Score Category
The trend is clear: S&P 500 companies have improved their ESG metrics over time — probably because they recognize the increasing importance of such scores and have taken steps to boost them.
ESG Scores and Performance
So do companies with high ESG ratings outperform their lower-ranked counterparts?
For insight on this, we created a High ESG Portfolio composed of S&P 500 companies that score above the median and a Low ESG Portfolio made up of firms that rate below it.
We built these portfolios on a monthly basis, from January 2008 to December 2018, using the ESG score of the companies. We then measured each portfolio’s returns over the next month, repeating the process for 132 months. We found that the High ESG Portfolio outperformed the Low ESG Portfolio by 16 basis points (bps) per year.
Performance of S&P 500 High and Low ESG Portfolios
|High ESG Portfolio
|Low ESG Portfolio
The geometric mean return of the High ESG Portfolio exceeds that of the Low ESG Portfolio even though the former’s arithmetic average return is lower.
Performance and Volatility of S&P 500 High and Low ESG Portfolios
|Arithmetic Mean Return
|Volatility (Annualized Standard Deviation)
|Geometric Mean Return
|Low ESG Portfolio
This counterintuitive result can be attributed to the difference in volatility. The High ESG Portfolio had much less, so its returns compounded better than those of the Low ESG Portfolio.
Over the long run, the cumulative performance of the two ESG portfolios is quite similar. We explore these and related results in much more granular detail in a longer companion piece.
High ESG Scores vs. Low ESG Scores: Cumulative Growth of $1
Do High ESG Score Equal Higher Quality?
Does the lower volatility of the High ESG Portfolio indicate higher quality?
There is indeed a positive correlation. We looked at the monthly payoffs of the Quality factor relative to our two portfolios and found a 0.41 correlation between the factor and the value added by the High ESG Portfolio compared to the Low ESG Portfolio. Additional testing of the Quality factor suggests an association of high ESG scores with higher quality.
Anecdotally, the High ESG Portfolio adds value more often during stock market declines. The correlation between stock market returns and the value added by the High ESG Portfolio over the Low ESG Portfolio is –0.27. This is statistically significant, with a t-statistic of 3.16. The phenomenon was most pronounced during the global financial crisis (GFC) in 2008 and the sharp recovery of 2009.
S&P 500 Companies: Performance during the Global Financial Crisis
|High ESG Portfolio
|Low ESG Portfolio
Addressing Some Common Concerns about ESG Investing
But what about ESG screens? By reducing the number of investable firms, do they act as a drag on performance?
The High ESG Portfolio’s investable universe was 26% smaller as measured by market capitalization due to the above-the-median ESG score requirement. That’s a significant reduction. Yet the High ESG Portfolio still performed well.
So, at a practical level, the theory that shrinking the selection of potential stocks based on ESG criteria will lead to lower returns is not supported by the historical data.
Moreover, active investors can incorporate ESG information in a holistic manner rather than mechanically screening firms out. This should render the concern a moot point for most investors.
As ESG investing grows more popular, investors are right to question whether it can be done without sacrificing returns. Our analysis shows that it can.
- ESG investing, even in a rudimentary, mechanical form, has generated returns that are highly competitive relative to the benchmark.
- Firms with high ESG scores demonstrate lower volatility and possibly higher quality.
Furthermore, based on our experience managing stock portfolios for more than 20 years, we believe active investors can use ESG data to better gauge company quality and apply that information, along with other relevant data, to make improved investment decisions.
The ESG debate is not a choice between having your cake and eating it too. Rather, ESG data is the icing on the cake: When prepared and presented well, it enhances both the having and the eating.
For more on environmental, social, and governance (ESG) investing from Gautam Dhingra, PhD, CFA, and Christopher J. Olson, CFA, don’t miss “ESG Investing: A Constraint or An Opportunity?”
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All posts are the opinion of the author. As such, they should not be construed as investment advice, nor do the opinions expressed necessarily reflect the views of CFA Institute or the author’s employer.
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