A couple with two kids seems to be the cliched family make-up and for many also the ideal. It makes sense to have two kids - you have created your replacements, your biological imperative is done. The children will have a sibling, and it seems everything - including car size, accommodation, even travel seems to better cater for this family size. But then what if you throw another child into the mix - by choice?
It's what my husband and I did. Last year we had our number three, and while it didn't make any sort of financial or logical sense, since we had him our family seems complete. It's a strange thing to admit, since having three children definitely takes a toll on your body - not to mention your finances - but a part of us felt we needed a third.
We aren't unusual in this, the recent HILDA (Household, Income and Labour Dynamics in Australia) survey found that by the time they are 40, most Australians wish they had more children than they actually have.
So what's stopping us having more kids? After all, Australia has had a declining fertility rate since the 1970s and we are still not at a replacement levels - which means women are having fewer than two children on average. Is it because by the time we have one or two kids we realise the actual cost of having children, both financially and emotionally, which stops us having more?
Dr Hayley Fisher from the School of Economics at Sydney University thinks there is more to it than that. "It's a common pattern internationally for people to report they want more children than they eventually have, and this difference gets smaller as people get older," she says. "For example, a woman intends to have three children, but doesn't meet the man she wants to have children with until much later life, so only has one child in the end."
Does it then mean that having more than two kids and giving them the sort of lifestyle most middle-class families want, is beyond the average family's reach? Possibly. "In Australia in particular, the unaffordability of childcare and low provision of paid parental leave create constraints that are very likely to prevent families from having a desired child," Dr Fisher says.
Sociologist Dr Leah Ruppanner from the University of Melbourne agrees. "Children are very expensive and without proper policy, the more kids you have the more expensive it becomes," she says. "In this day and age, to have a wife who is fully out of the labour market and not working at all, becomes an increasingly important marker of status because it means you can look after three babies and give them the quality of life you want."
The status of having many children was famously noted by Tina Fey in an article she wrote for The New Yorker. "All over Manhattan, large families have become a status symbol. Four beautiful children named after kings and pieces of fruit are a way of saying, 'I can afford a four-bedroom apartment and $150,000 in elementary-school tuition fees each year. How you livin?'."
A 2008 study in the US confirmed there was a significant rise in the proportion of three and four-child families among the super-rich - that is the top 1 per cent to 1.5 per cent of wealthiest Americans. This trend is especially noticeable in Manhattan and parts of Brooklyn where more than half of wealthy families have more than two kids. While another study published in the Economic Journal found that there was also a significant increase in fertility rates for highly educated women and that many of these women were opting out of the work force. What could explain this seemingly sudden leap in fertility among the very rich and educated?
"What the wealthiest parents have on their side is that they are more able to afford assistance from nannies, tutors and other helpers to help with this burden," Dr Fisher says.
For example, after announcing he and Kate were expecting their third child, Prince William was said to be more confident this time round because he had his staff in place.
But for highly educated women it could be something different. Dr Ruppanner believes they could be having a number of children and not returning to the workforce in response to an unjust system. "You're getting knocked out with your first kid and further buried with your second. And then you're thinking how am I going back to my work? So I will have a third. Although, if highly educated women had it their way they wouldn't be spending their lives baking cookies necessarily."
For us and most average couples who go on to have three or more children, status has nothing to do with it. As Dr Fisher says, "given the financial, time and emotional costs of children it seems unlikely that 'status' would be enough to compensate parents for having [more] kids." It was a purely emotional decision for us and one that we were lucky enough to have been able to make. But for those average families on the fence about having more kids, sometimes the decision ends up being about finding a balance between money, work and quality of life.
If the government wants to raise our dwindling fertility rates, however, it needs to do some long term thinking and make drastic policy change. As Dr Ruppanner reiterates, "It's about the policy. You need a policy or workplaces that are more conducive to mothers." Until then it seems the decision to have more than two kids may be relegated to the very wealthy, or like us, slightly irrational.