New Research Reveals UK's Gender Pay Gap Has Been Underestimated for Over 20 Years

• New evidence reveals that the UK's gender pay gap has been underreported for over 20 years
• The research, published in the British Journal of Industrial Relations, points out issues with how data has been gathered

The UK's gender pay gap has been underreported for over 20 years, casting into question the accuracy of official statistics that inform key policies, such as the national minimum wage.

Research in the British Journal of Industrial Relations discovered that, since 2004, the Office for National Statistics (ONS) has under surveyed smaller companies in its Annual Survey of Hours and Earnings (Ashe).

It biased the statistics in favor of larger companies, where pay is greater and gender pay gaps narrower, resulting in a persistent underestimate of about one percentage point.

By official stats, the gender pay gap between full-time workers was 7 percent in 2024, but on their analysis, it is really nearer 8 percent.

The inaccurate figures are significant because ONS statistics are used to influence pay for doctors and nurses, to help determine the minimum wage, and as a benchmark for employers who are asked to report pay gaps.

Professor John Forth, the report's main author at Bayes Business School, stated that incorrect estimates might have hindered efforts to narrow pay gaps since policymakers might have taken more aggressive action earlier if the gap had been made apparent to be higher.

The ONS admitted the study posed "interesting questions" on data weighting but maintained that the overall impact on findings is minimal. It stated it has already taken steps to improve Ashe and was considering its sampling techniques.

Aside from the statistical deficiencies, gender pay gaps are still glaring. Women, on average, receive £631 less per month than men, Fawcett Society figures show, with Bangladeshi, Pakistani, and Mixed White and Black Caribbean women experiencing among the largest gaps.

Although the gender pay gap has diminished over time—dropping from 27.5 percent in 1997 to 13.1 percent in 2024 for all staff—campaigners are insisting that persisting inequality requires swift action.

As Tom Heys of Lewis Silkin observed, slightly better statistics do not alter the root issue: "The government and employers still have to address the structural causes of pay inequality."