Men already earn more than women in the workplace, but research has shown that when men become fathers they often get paid an additional bonus.
Bosses were more inclined to give new fathers a "daddy bonus" on the assumption they were more dependable and the breadwinner of the family, according to a University of Colombia study.
It was found that the extra pay was regardless of the quality of their work, but was based more so on an underlying view that new fathers had greater responsibilities and costs associated with a growing family. However, when their work was subjected to performance reviews, the wage boost was often reduced.
"Although women typically experience a dip in earnings after becoming mothers, our study confirms the prevalence of the so-called 'daddy bonus' – the wage boost that men enjoy when they become fathers," associate professor and lead author Sylvia Fuller said.
"Our findings suggest that employers are more likely to see fathers as deserving of promotions and higher wages because of an unfair assumption that men are the breadwinners in their families, and are therefore more likely to be hardworking and dependable.
"Of course, that assumption isn't always true."
Researchers examined data from Statistic Canada's Canadian Workplace and Employee Survey looking at the wages of 18,730 men, between 22 and 44-years-old, across 5,020 workplaces.
They found that fathers working in professional or managerial occupations were paid an additional 6.9 per cent, compared to a 3.6 per cent wage increase in other occupations.
The wage boost was reduced in workplaces where there was greater scrutiny over work performance.
"The overall story seems to be that, when there's more scrutiny and oversight of actual performance, the fatherhood advantage diminishes," Ms Fuller said.
"This suggests that it's not so much that dads are necessarily working harder, but that employers think they are.
"It is discrimination on the basis of family status. Not everybody wants to have kids, but that shouldn't affect wages. That's fundamentally unfair."
Money expert, from finder.com.au, Bessie Hassan said the idea of a "daddy bonus" was built on outdated views.
"The traditional role of males as breadwinners may have some impact on this. In addition, the additional financial pressure having a baby brings may become a consideration for employers when assessing their employees' performance and remuneration," Ms Hassan said.
"Whether or not an employee has children should not form part of the discussion, and certainly not the decision when it comes to whether you're entitled to a pay rise.
"Social change takes time – decades and in some instances, generations."
Traditional profiling aside, payrises should always be on merit.
"Remuneration should always be based on the skills and attributes that one can brings to the role and organisation, regardless of gender (or parental status)," Ms Hassan said.
However, there was an argument that some employees were more efficient after becoming parents.
"The reality is working parents are extremely dependable and hardworking," she said.
"As a parent myself I can tell you firsthand, parents are masters when it comes to multi-tasking which makes us dependable and also incredibly productive in and outside of the workplace.
"As well as being dependable, parents make the hours in the office really count which make them highly efficient."
If that was the case, both men and women should be viewed as worthy of a bonus, after becoming parents.
Ms Hassan said one factor not taken into consideration, when looking at wage increases, was that more men asked for pay rises, than women.
"Almost two in three Australians (58 per cent) who ask their boss for a pay rise get one, according to our research," she said.
"Worryingly, women were far more reluctant to ask for a pay rise, with only 18 per cent having sought a pay bump versus 32 per cent of men."