Having a child increases your pay - but only if you're a man
Mothers in full time work, conversely, experience a wage "penalty," earning 7% less than women without children when variations are accounted for.
The report said that this could be down to a number of factors:
"Reasons for the fatherhood bonus are not clear, though it is likely to relate to hours worked, increased effort and positive discrimination."
Overall, full-time women earn 34% less than similar full-time men by the age of 42. The report stressed that the penalty is largely - but not entirely - associated with the impact of parenthood on earnings.
Mothers are still much more likely than fathers to be primary carers for dependent children, and in turn are more likely to have periods of part-time work resulting in fewer hours and a pay decrease.
Wage benefits for men didn't just stop at being a fatherly status though: those with two or more children earn 8% more than similar fathers with just one child, while for working mothers the number differential has little impact.
This could be because rich families may decide to have more children than those with less money, the report said, suggesting the link was correlative rather than causative.
A new scheme to encourage paternity leave by offering more flexitime came into effect last year, but fewer than 1% of fathers have taken advantage of it.