Among the 53 investors backing the WDI are Europe's largest investor Amundi, Canada's BMO Global Asset Management, HSBC's fund arm and Britain's university pensions scheme.
From pay to working hours, health and safety to workforce discrimination, the social behaviour of companies is increasingly a focus for investors following the #MeToo campaign and the Black Lives Matter protests.
But out of 750 companies asked by investors to provide information to the survey, 141 (19%) did so in 2020.
That was nevertheless a 20% increase from the 118 in 2019.
Of those that answered, 75% gave the gender breakdown of employees but - despite 98% pledging to improve diversity within their ranks - only 36% reported the ethnic composition, making progress towards racial diversity targets difficult to track.
While 57% of companies provided data on their gender pay gap, only 4% reported their ethnicity pay gap, excluding companies that said they were legally prohibited from collecting ethnicity data.
"Without this data, companies are effectively taking a shot in the dark, implementing practices without knowing who is in their workforce, and what it is that they need," Charlotte Lush, research manager at WDI, said.
While 96% of companies provided data on their discrimination and harassment policies, less than half as many (41%) disclosed how many incidents were reported.
Similarly, 91% of companies made a public pledge about respecting human rights, but 45% of these could not give an example of when they had resolved a human rights violation.
After a year marked by a number of high-profile complaints about worker mistreatment - including at Amazon, Deliveroo and Boohoo - investors' requests for more data saw companies including Nike and Vodafone respond for the first time.
The number of respondent companies who disclosed the ratio of CEO to median worker pay increased to 74% in 2020, from 48% in 2019, but ShareAction said higher levels of disclosure did not equate to higher pay ratios.
British supermarket Sainsbury's disclosed the most information about its supply chain. Commercial property firm Land Securities had the most complete survey response overall.
"Effective human capital management can facilitate economic mobility and close opportunity gaps within the workplace and global supply chains," said Amy Augustine, Director of ESG Investing at WDI signatory, Boston Trust Walden.
Amazon, Google-owner Alphabet, JPMorgan Chase and Walmart were among companies that did not disclose information for the survey, ShareAction said.
(Reporting by Simon Jessop and Elizabeth Howcroft; editing by Barbara Lewis)
(Only the headline and picture of this report may have been reworked by the Business Standard staff; the rest of the content is auto-generated from a syndicated feed.)
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