It’s widely known that women face a lifetime pay gap due to motherhood. But men? They actually profit from becoming a parent, suggests new research from University of British Columbia.

Published in the journal Work, Employment and Society, the new study further explores the gender pay gap, finding that men often receive a wage boost when they become fathers, regardless of whether they actually work harder. In fact, men whose work was subject to performance reviews received a comparatively lower new-dad pay boost or none at all.

“The overall story seems to be that, when there’s more scrutiny and oversight of actual performance, the fatherhood advantage diminishes,” says lead author Sylvia Fuller, associate professor in the university’s department of sociology. “This suggests that it’s not so much that dads are necessarily working harder, but that employers think they are.”

The researchers analyzed data from Canadian government surveys between 1999 to 2005, which included 18,370 men ranging between ages 24 and 44 years, from 5,020 different workplaces. They limited their study to data of only white men, because using non-white men would require accounting for potential racially discriminatory wage gaps.

They found that fathers in professional or managerial occupations gained the largest net wage boost — a 6.9% increase in earnings — as opposed to dads in other occupations, who received an average net wage boost of 3.6%. And more educated fathers, who held a university degree, received a higher net wage increase of 5.3% compared to 1.8% net wage increase for fathers with who did not complete high school.

But in work environments where pay decisions were more clearly based on performance, researchers found that the fatherhood wage boost diminished or even reversed, for least-educated men. Working in a firm with human resources, or participating in collective wage-bargaining (as in the case of professional unions), also made fatherhood wage boosts less likely.

“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,” Fuller says. “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.”