Presenting gender pay gap information as piles of coins, rather than percentages, has the biggest impact on people in terms of their understanding of the information being presented, according to the report commissioned by the Government Equalities Office.
More than 2,300 people took part in the research, conducted by the Behavioural Insight Team with input from experts at Harvard Business School and the University of San Francisco.
The randomised control trial aimed to find the best way of presenting gender pay gap data in order to help people identify which companies are doing better than others, understand what the figures mean, and hold the right companies to account.
Britain was the first country in the world to force employers to publicly disclose their gender pay gap figures, with the law coming into effect in April 2017.
"This landmark legislation enables one of the most powerful behavioural mechanisms, transparency, to begin shifting how employers think about and act on their gender pay gaps," according to the report.
It warned: "But transparency only helps change employer behaviour if people can hold employers to account. This means that the public has to correctly interpret the information they’re given and use it to drive decisions such as what to purchase and where to work."
The report noted: "Merely eliciting employer fear of reputational damage and public discontent is often enough to spur companies into action, but that requires that employers also believe that the public can understand the information that is being presented."
Four different ways of portraying the gender pay gap were tested. One simply showed the data in a bar chart. The remaining three methods used benchmarking information, comparing the company against others. One used the bar chart approach, another used coins and pounds and pence; and the third used an energy efficiency-style graphic.
The coins had the most impact, according to the report, which was released last month. It stated: "When the figures were presented as money, and visually as piles of coins, together with benchmarking information (comparing the company to others), people’s attitudes were most accurate and comprehension was highest."
The report added: "This may be because coins were more concrete and easier to relate to than percentages."
Its findings have prompted the Government to change the way it displays the gender pay gap information. "As a direct result of this research, the current live version of GPG (gender pay gap) viewing service now shows every employer’s GPG as money in addition to the percentage."
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