We dwell in an period of accountable and sustainable funding, with environmental, social, and governance (ESG) concerns assuming ever-increasing significance and precedence in funding resolution making and portfolio building.
Between 2014 and 2018, the overall worth of “sustainable and accountable” funding property in the USA grew at a compound price of 16% each year to $11.995 trillion, or 25.7% of all managed property. Whereas the societal advantages of ESG investing could seem apparent, whether or not socially accountable funds generate superior risk-adjusted returns in contrast with their standard counterparts nonetheless has no clear reply. Some research report proof of a optimistic relationship between socially accountable investing and irregular returns, whereas others report a damaging relationship.

One other huge query for researchers is whether or not the appliance of ESG values might result in market inefficiencies — and subsequently create the potential for irregular returns. Earlier research have largely centered on measuring returns inside brief intervals across the announcement of ESG-related information. Ours is the primary to look at longer-run returns as much as 90 days after ESG bulletins.
Our investigation was motivated by different research highlighting how giant inflows into funds with excessive social duty scores encourage institutional traders to focus comparatively extra on ESG traits of shares than fundamentals, and the way socially accountable funds are much less inclined to promote shares with excessive ESG scores, even after damaging information on fundamentals.
We started with the prediction that investor bias in direction of ESG concerns may lead to overreaction to ESG-related information bulletins. This prediction was grounded in salience concept, which holds that when the eye of resolution makers is disproportionately directed to 1 or just a few elements — on this case, ESG points — these elements will obtain disproportionate weighting in subsequent judgments.
We theorized that this prediction ought to apply significantly to ESG controversies, on condition that dangerous information tends to be extra salient than good. Thus, when institutional traders observe a damaging shock to the ESG attributes of a inventory, we anticipate they may are inclined to overestimate the chance of additional shocks, leading to a stronger tendency to promote and a bigger fall within the inventory value than basic concerns may justify.
Our research demonstrates that the value response to ESG information occasions is extra pronounced for corporations with a better institutional holding earlier than the information launch and that there’s a statistically vital lower in institutional holdings following the discharge of dangerous ESG information in contrast with adjustments after excellent news.
If these return patterns could be attributed to institutional investor overreaction, then we anticipate each the announcement returns and subsequent imply reversion to be stronger when alternatives for arbitrage are extra restricted. Thus, we present that the irregular returns are stronger for smaller shares, which have larger volatility and are more durable to brief promote. Additional, in line with the prediction that damaging phenomena will appeal to extra consideration than optimistic, we additionally present that the overreaction is larger for dangerous ESG information than good ESG information.
Strategies and Findings
The research centered on the constituent shares of the S&P Composite 1500 Index in the USA. We used return information from the Middle for Analysis in Safety Costs (CRSP) and sourced details about ESG information occasions from RavenPack Information Analytics’s Dow Jones Version, which incorporates materials from Dow Jones Newswires, which covers the Wall Road Journal, Barron’s, and MarketWatch. By making use of filters to RavenPack’s information classification system, we have been in a position to isolate particular person occasions in ESG-related sub-categories. (These classes are labor points, conflict battle, safety, pure disasters, air pollution, industrial accidents, civil unrest, company duty, crime, and well being.)
Occasions have been categorized additional — as optimistic or damaging — utilizing RavenPack’s information sentiment methodology. Our last pattern comprised 82,435 firm-event observations between January 2000 and December 2018.
Inventory returns round ESG information occasions have been examined utilizing the occasion research statistical technique that usually employed when assessing the affect of an occasion on the worth of a agency. (For mannequin specs, discuss with the primary paper.) The tactic includes discovering the irregular return attributable to the occasion, adjusting for returns that stem from Carhart 4 elements — market threat, measurement, worth, and momentum. To measure the returns round ESG bulletins, we calculated the cumulative irregular return (CAR) for 21 buying and selling days centered on every information launch day.
Throughout all corporations in our pattern, the research discovered a statistically vital cumulative irregular return on the 0.01 degree for the 21-day window of -0.773% round dangerous information, whereas the typical irregular return of -0.004% round excellent news was insignificant. The findings are in step with our prediction that the habits of institutional traders would replicate their concern about fund outflows after they held shares topic to ESG controversies.
To reveal the return patterns round ESG information bulletins, we collated cumulative common irregular returns for 21 days throughout quite a few classes (see Determine 1). First, we separated occasions into excellent news and dangerous information. Second, we categorized shares in response to measurement, collating separate outcomes for corporations within the S&P 500 Index.

The outcomes present a transparent damaging irregular return when firms are topic to dangerous ESG information, however no clear sample round optimistic ESG information. The damaging returns round dangerous ESG information are considerably bigger in magnitude for the smallest shares. There’s additionally proof of doable leakage of data forward of dangerous information occasions, as cumulative irregular returns start occurring a number of days earlier than information releases.
We additionally examined irregular buying and selling volumes from 10 days previous to the ESG information announcement to 10 days after. The outcomes are offered in Determine 2. (The irregular buying and selling quantity is calculated because the ratio of buying and selling quantity at day t of the buying and selling quantity averaged between day t = −255 and t = −46.)
We recognized a transparent enhance in irregular volumes round dangerous ESG information and solely a small enhance round optimistic information. The rise round dangerous ESG information was additionally extra pronounced with smaller shares and — in line with different proof of potential leakages of data — there was a rise in irregular buying and selling volumes a number of days earlier than the discharge of dangerous information.
We additionally examined which classes of ESG dangerous information generated the best inventory value response (see Determine 3) over the 21 buying and selling days centered on the ESG information announcement date. The biggest damaging irregular returns have been associated to company governance: power majeure. during which a agency seeks to be excused from performing its a part of a contract; discrimination defendant during which the corporate is sued for discrimination; and antitrust swimsuit when the corporate is the defendant in a authorized motion for unfair enterprise practices.
To additional check the proposition that traders with a powerful concentrate on corporations’ ESG traits are prone to overreact to ESG information, we analyzed institutional investor holdings round ESG information occasions. The outcomes verify a sample of decreased institutional holdings across the time of dangerous ESG information and the change in institutional possession round ESG occasions was additionally noticeably bigger for small- and mid-cap shares. The outcomes present additional proof of a subset of institutional traders promoting inventory holdings following ESG controversies, and in doing so, contributing to vital damaging returns across the time of the occasion.
If traders overestimate ESG threat for a inventory after a foul information occasion, it follows that the response of the market shall be out of step with the change in fundamentals related to the information — and irregular returns will outcome. To check this proposition, we examined longer-run post-announcement returns subsequent to the preliminary damaging returns round ESG controversies.
Proof of optimistic irregular returns within the 90-day interval after dangerous ESG information bulletins is proven in Determine 4 beneath. As we predicted, returns have been bigger in magnitude for smaller capitalization shares, and there was no long-term pattern in irregular returns following optimistic information bulletins.
Along with the singular relationship between ESG bulletins and returns, we performed a multivariate evaluation to see whether or not explicit traits of firms affected returns round ESG bulletins. We additionally examined whether or not overreactions have been accentuated in small corporations and in these with a big proportion of the excellent fairness held by transient institutional traders.

Our multivariate evaluation confirmed that the irregular returns round dangerous ESG information have been higher than round good ESG information and that irregular returns round dangerous ESG information have been bigger for smaller corporations. Equally, the irregular returns have been bigger for corporations with a higher proportion of transient traders, demonstrating the follow-on results of such traders overweighting the chance of realizing ESG dangers once more sooner or later.
Conclusion
Salience concept means that traders overestimate the chances related to salient occasions. So when an ESG controversy happens, traders overestimate the probabilities that the occasion will recur and subsequently overreact to the information. In step with this proposition, our research discovered a damaging impact on returns when damaging ESG information was launched, however that these returns imply reverted over the following 90 days.
The impacts — each for announcement returns and subsequent reversals — have been strongest for smaller capitalization shares and people shares held by extra transient traders earlier than the information launch.
Our analysis has a number of vital implications:
- First, we reveal the possibly antagonistic implications for market effectivity of biases induced by the rising concentrate on ESG data.
- Second, our research reveals why institutional traders that undertake ESG of their data set have to fastidiously situation their buying and selling actions round ESG information releases to keep away from overreaction and consequent losses.
- Lastly, given the noticed overreactions to ESG information, there could also be potential for contrarians to purchase shares after the discharge of damaging ESG information and immediate from the following imply reversion.
For extra on this topic, try the full research from Bei Cui, PhD, and Paul Docherty, PhD.
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All posts are the opinion of the creator. As such, they shouldn’t be construed as funding recommendation, nor do the opinions expressed essentially replicate the views of CFA Institute or the creator’s employer.
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