A code of ethics aligned to modern slavery policies make the difference between companies making a meaningful commitment and those simply tick boxes, according to leading academics.

Writing for the Institute of Business Ethics, professors Sepideh Parsa and Andrea Werner say their research of documents from 2019 to 2023 shows that modern slavery reporting has improved but codes of ethics make the difference.

“We found that while many firms improved their modern slavery disclosures over the five-year period, it is the quality and clarity of their C of E [code of ethics] and its alignment with modern slavery statements that distinguishes substantive commitment from symbolic compliance.”

They add that companies with “clearer, more accessible and action-orientated” codes “demonstrate stronger governance, transparency and due diligence”.

Their conclusions come as the UK marks a decade since the Modern Slavery Act was introduced in 2015 making key disclosures mandatory. Earlier this year the government introduced new guidance for modern slavery reporting which “emphasises practical steps to prevent, identify and respond to modern slavery”.

Researchers from CLLA, the investment manager of £15.8bn in assets, issued a report in March claiming too few global companies find modern slavery in their supply chains which suggested due diligence practices did not reach an appropriate quality.

CCLA’s research showed only 23 of the world’s largest 100 companies with UK operations had found modern slavery in supply chains. Expert estimates suggest there may be as many as 50 million men, women and children worldwide trapped in forced labour conditions.

Martin Buttle, CCLA’s better work lead, said: “We are slightly alarmed given the size and influence of the companies that we’re benchmarking.”

Of the companies that found forced labour, 13 reported a mode of redress but only one reported if the victims were happy with the outcome.

Writing for Board Agenda, Dame Sara Thornton, a consultant for CCLA, said: “We understand that initially there might be reluctance to speak openly about cases of modern slavery when they are found.

“However, it is present in almost every supply chain — if you are not looking and finding modern slavery, you are simply not looking hard enough.”

Parsa and Werner offer good practice examples of companies reporting well on their approach to modern slavery.

Energy giant Shell “embeds” modern slavery commitments into its code of conduct enforced announced and unannounced site visits.

BAT also linked standards of conduct to CSR policies and audit committee oversight “ensuring modern slavery risks … inform governance decisions and supplier accountability”.

Parsa and Werner write: “Embedding values into governance, due diligence and worker engagement strengthens both ethical practice and long-term resilience.

“When strategically aligned with governance systems and operational practices, these codes do more than communicate standards —they form the took enable accountability.”