What Pay Transparency Can—and Cannot—Change

This series has treated pay transparency as an accountability system rather than a promise attached to a salary range. The final question is what the evidence allows us to say about that system: which links can change wage paths and organisational choices, which links are missing in common designs, and which sources of gender inequality require more than disclosure. The reader should leave able to judge a transparency proposal by its signal, comparison, audience, agency, action, enforcement, burden and boundaries.

The answer is conditional, but it is not evasive. Public pay-gap reporting can change what firms do. It can alter the growth of wages, bonuses and promotions, expose employers to reputation and recruitment pressure, and give workers, representatives and regulators a basis for asking harder questions. But the UK evidence also shows that a smaller gap may result mainly from slower growth in men’s pay, with no statistically significant average increase in women’s pay. The OECD comparison shows that public access, valid job comparisons, worker representation, follow-up and enforcement determine whether a disclosure system becomes more than a published number.

A smaller gap is real, but it is not the whole verdict

The strongest evidence comes from the UK’s near-threshold study. Firms just above and below the 250-employee reporting threshold were compared before and after the public reporting obligation, using linked employer-employee payroll data and a design that compares firms, time and gender. The study estimates a relative increase of about 3 percentage points in women’s hourly pay compared with men’s, corresponding to a 19% reduction in the pre-policy gap in the study’s sample. The result is local to firms near the threshold and conditional on the study’s identification assumptions, but it is more than a before-and-after association.

The direction of the effect is the central qualification. Men’s real pay growth in treated firms slowed by about 2.9% relative to comparable control firms. The average effect on women’s pay was not statistically significant. The best-supported conclusion is therefore that public reporting changed the relative path of pay near the threshold, primarily through pay compression. That is a real equality effect in the measured relationship, but it is not the same as raising women’s earnings or removing the conditions that produce unequal opportunity.

The result also reaches beyond the base salary line. The UK analysis finds patterns consistent with lower growth in additional payments and fewer promotions, although the average promotion estimate is not statistically significant and the dynamic evidence is noisier. Hiring and overall new-hire composition do not show a clear effect; possible movement of women toward better-paid occupations is suggestive, and an apparent increase in women’s separations does not survive all robustness checks. These distinctions matter because a firm can change a reported average through existing workers’ pay, reward rules, promotions, hiring, departures or combinations of those paths.

The public mechanism is plausible but less certain than the wage estimate. Firms with larger published gaps received worse placements in two YouGov reputation rankings, and high-advertising firms appeared to respond more strongly to the reporting requirement. Those patterns are consistent with public scrutiny affecting employers whose brands and recruitment markets make reputation valuable. They do not prove that reputation was the sole cause of the wage response. The rankings covered a short period and selected firms, and advertising intensity can capture other characteristics such as size or industry.

This evidence answers the title’s first question. Pay transparency can change more than the salary range because it changes the audience and timing around pay decisions. A public firm-level gap can become information for workers, applicants, customers, investors, journalists and other employers. It can make an organisation’s pay distribution part of its public identity. A salary range, by contrast, mainly changes the information available before a job is accepted. Both can affect bargaining, but public reporting also creates repeated comparison and reputational exposure after hiring.

The OECD stocktake supports the importance of this distinction while resisting a universal claim. As of July/August 2025, 21 of 38 OECD countries required private-sector gender-pay-gap reporting, and 12 required some public disclosure. The report expected 32 of 38 countries to require private-sector reporting by the end of 2026, with the expansion driven largely by the EU Pay Transparency Directive. Yet only 10 of the 21 reporting countries also required private-sector equal-pay auditing at that point. Coverage among nine countries that supplied estimates ranged from about 4.4% of private-sector workers in federally regulated Canadian jobs to 68% in Belgium.

Those figures describe policy reach, not policy success. A country can have a reporting rule that reaches many firms but provides little public access. It can publish a score that is easy to compare but poorly aligned with work of equal value. It can require an audit that identifies a gap but does not connect the result to salary decisions. It can create a right to information that few workers use because the burden of requesting and interpreting it is too high.