The stay-at-home mum versus the working mum debate ignores many important factors of modern family life.

The stay-at-home mum versus the working mum debate ignores many important factors of modern family life.

Forget The Hunger Games. A much more brutal and devastating battle is raging: the mummy wars. In one corner, the layabout, soap opera-obsessed stay-at-home mum, or SAHM. In the other, the negligent, money-obsessed working mum. Only one mother can win - by tearing shreds off her opponents and generally out-bitching the other.

The prize? Moral superiority as the best kind of mother, woman and human being.

The perception of ‘mummy wars’ only plays into the stereotype of women as emotion-driven creatures who are out to get one another 

Sounds ridiculous? Maybe, but there's an ugly grain of truth in there. What working woman hasn't secretly begrudged the SAHM their easier workload? What SAHM hasn't secretly thought working mums neglect the needs of their kids? We women can be pretty hard on each other – almost as hard as we are on ourselves.

A fresh round of mummy wars broke out in the US last week, when a Democratic talking head, Hilary Rosen, said the wife of Republican presidential candidate Mitt Romney had no basis on which to advise her husband on economic issues because she'd “never worked a day in her life”.

Ann Romney opened a Twitter account to complain: ''I made a choice to stay home and raise five boys. Believe me, it was hard work.''

So the old catfight was out of the bag again, attracting a stream of online commentary and a prompt intervention by Barack Obama saying the work choices of candidate spouses were irrelevant. An apology from Rosen followed.

The mummy wars are obviously a simplification – and not just because the concept ignores the bulk of mothers who contort themselves on a daily basis to juggle family and work. It also assumes that women alone are responsible for their decisions, and that they do so based on their preference for work or child rearing.

In reality, for many mothers, the decision to work is purely a financial one. And it isn’t a decision they make alone (excluding single mothers), but a negotiated outcome between partners in a relationship.

We need to think about families not as a homogenous unit but as a collection of individuals, who can be deployed in various ways to maximise the family’s wellbeing.

In the same way that economies get rich when individuals specialise in what they’re best at and then trade, families are better off when their members specialise where they have a comparative advantage.

Traditionally, men have earned more money selling their labour in the market, so it made sense for them to do that while women stayed at home to look after the children.

Decades ago – when women typically didn’t go to university and were expected to work as secretaries, teachers and nurses – it made financial sense for the woman to devote her labour to domestic duties rather than paid work. For their generation, the Romneys probably made the best economic decision they could.

But for couples making these decisions today, the landscape has changed dramatically.

Today's young women have more than proved their equal ability to earn degrees and hold high-powered positions. According to figures from Graduate Careers Australia, women make up 64 per cent of university graduates.

Male graduates continue to earn marginally more than female graduates, with median starting salaries of $52,000 versus $50,000 last year. But today's female graduate earnings are fairly close.

Then something happens to women and their salaries when they enter their 30s … and that ‘something’ is children.

Couples today make more active decisions about who will take time out of the paid workforce to look after their children. They must consider which partner has the higher earning capacity and whose career progression will be most affected by taking time out.

In a sense, because many couples are delaying childbirth until their 30s, partners have had almost a decade to establish themselves in their chosen careers, and are in a better position to decide who has the highest skills and career prospects.

Because the market value of women's time has risen so dramatically, it’s more common that the man is the stay-at-home half of the couple while the woman goes out to earn her salary.

The economics of the family are evolving. Where gender policies and quotas fail to deliver, the profit motive will win out.

It will take time. It requires governments to keep working to remove tax traps that keep women at home because they would lose more in welfare benefits and tax than they would earn. It requires greater attention to the provision of high-quality, cheap childcare.

And public debates about the choices families make should have the emotion taken out of them.

The perception of ‘mummy wars’ only plays into the stereotype of women as emotion-driven creatures who are out to get one another. This perpetuates one of the most dangerous stereotypes for all mothers – that childbirth permanently transforms them into hormonally unbalanced basket cases.

Decisions about work and family life should be respected for what they are – largely financial decisions about what will maximise a family's income and wellbeing. It's time to call a halt to the war.