The majority of the UK's gender pay gap cannot be explained by differences in characteristics of men and women, or the types of jobs they do, according to new analysis from the Office for National Statistics (ONS).
It found that 36.1 per cent of the gap could be explained by a difference in characteristics of the two genders, and the jobs they do, considering aspects such as occupation and how long people had been in their roles.
The ONS said occupational differences were the biggest factor, accounting for 23 per cent of the gender pay gap, whilst 9.1 per cent can be explained by the difference in working patterns. Men are more likely to work full-time, and full-time employees on average earn more.
But, 63.9 per cent "cannot be explained", with the ONS saying information on family structures, education and career breaks could provide greater insight.
The report said:
Factors such as the number of children, the age of children, whether parents have any caring responsibilities, the number of years spent in school and the highest level of qualification achieved are likely to improve the estimation of men’s and women’s pay structures and consequently decrease the unexplained element of the pay gap.
While the ONS said the unexplained aspect should not be interpreted as a measure of discrimination, it did say that could play a part in the gender pay gap.
The gender pay gap is defined as the difference in median pay between men and women, and the ONS' headline measure is the difference between median gross hourly earnings, excluding overtime, as a proportion of median gross hourly earnings for men.
The median hourly pay of women in the UK is 9.1 per cent lower than that for men. For the UK as a whole, the gap has reduced; in 2011 it stood at 10.5 per cent, though it is still in favour of men.
Analysis from the ONS last year found London however, has the largest gender pay gap in the UK at 14.6 per cent.
Firms in the UK with more than 250 employees have until the beginning of April to publish details on their gender pay gap.
At present just over 600 of around 9,000 businesses that need to do so have published the data. Those that fail to provide the information could face unlimited fines and convictions, according to the Equality and Human Rights Commission.