Still, some investors also use ESG information to promote social goals, the study found. It noted, for example, that five of 14 investors interviewed by the GAO said they created ESG-focused investment funds or portfolios with the aim of pushing social responsibility and environmental sustainability.

The GAO report, which was sent to Sen. Mark Warner, D-VA, a member of the Senate Banking Committee, was undertaken because "investors are increasingly asking public companies to disclose information on ESG factors to help them understand risks to the company's financial performance or other issues, such as the impact of the company's business on communities."

The study relied on interviews with seven private asset managers and representatives from seven public pension funds. It analyzed 32 large and mid-sized public companies found across eight industries representing a range of U.S. economic sectors. And it looked at the companies' disclosures regarding 33 ESG topics chosen because they were "frequently cited as important to investors by market observers."

According to the GAO's report, the companies examined put forward the most disclosure on topics tied to board accountability, climate change and workforce diversity. Conversely, they provided the least amount of disclosure on topics linked to human rights.

The report noted, though, that "the SEC requires companies to report certain governance information in their proxy statements in advance of shareholder meetings where shareholders elect members of the company's board of directors, which may help explain why board accountability topics are the most reported across industries in our sample."

It was also noted that "differences in disclosure can result, in part, from the relevance of an ESG topic to a particular industry" such as airline and oil and gas industry companies disclosing more climate change information.

Regarding some of the proposed new legislative or regulatory actions, the study found that some investors and companies interviewed "indicated … that new or additional SEC interpretative releases addressing how ESG topics fit within existing disclosure requirements could be helpful," said the report.

Still, "some institutional investors, companies, and market observers have cautioned against legislative and regulatory intervention in ESG disclosures and have recommended private-sector approaches to improve companies," the report said.

"One advantage of private-sector approaches is that because they are voluntary, they provide companies with flexibility," said the report, before adding that "some investors and companies said flexibility was important in ESG reporting because the relevance of ESG issues can vary by company and change over time."

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