father and baby
Fathers are important for a child's wellbeing. Photograph: Mimi Haddon/Getty Images

'My father had a profound influence on me," Spike Milligan used to say. "He was a lunatic." Fatherhood has spent a long time anchored in the dark ages, refusing to budge no matter how many tributes from doting daughters or portraits of the Beckham brood entwined with dad are published.

There are various stereotypes of fatherhood, none of them especially flattering. Dads may be viewed as present but highly incorrect; demonic, dismissive and violent. Or they are absent, deadbeat, disengaged and damaging. Or they may be incompetent domestic buffoons, aimlessly wandering through supermarket ads, ridiculed for their ineffectualness.

A new report by the thinktank IPPR, to be published in the new year, shines a further light on that most traditional role of all for dads – that of breadwinner. The report analyses data about men and women born in 1958 and 1970 to "assess the impact of 50 years of feminism on the way we live today".

Mothers born in 1958 who had children by the age of 40 could expect to earn 32% less than a father born in the same year. Mothers born in 1970 could expect to earn 26% less than the average father by their late 30s.

What the IPPR work also reveals is a surprising "fatherhood pay bonus" among men. Fathers born in 1958 could expect to earn 16% more by the age of 40 than childless men. Fathers born in 1970 reap an even higher reward. They earn 19% more than non-dads.

Why should this be so? Academic evidence suggests that fathers earn more because they are compensating for a partner who works less once children arrive. Fathers may also stick at jobs because of their parental responsibility and are rewarded for their loyalty.

Feminism focuses on getting women out of the home. It therefore requires men to become more firmly ensconced in it, doing their domestic duty hopefully beyond the control of those women who insist there is only way to do it "right" – and that's their way.

However, if dads continue to earn substantially more than anyone else, that makes it very much harder – even "irresponsible" in the view of some – if they choose to cut back on their hours to spend more time with their offspring. Yet that is exactly what poll after poll tells us that more and more men desire. Welcome to a checkmate on change.

How is the impasse broken? Fairer wages for women is one obvious answer. But it might also help if we all paid more attention to the ever-increasing quantity of research that details the many ways that fathers do count and not just for their cash. Boys and girls learn better, aspire to more, are more likely to desist from harmful behaviour and are more emotionally stable if they have positive experiences of involved dads.

It's not just what dads do, but also how they prepare to father a child, that makes a real difference to the outcomes of their sons and daughters.

The New York Times recently reported that the health of the unborn child is affected by what and how much would-be dads eat; the toxins they absorb; the traumas they endure and their age at the time of conception. Negative stereotypes have endured because "to father" has yet to carry the value of what it means "to mother". Reassessment is overdue.