No matter who you are, the birth of your child will be one of the most joyous days in your life.

As a demographer, you get to enjoy birth-related joy every year as the Australian Bureau of Statistics (ABS) releases its annual birth dataset.

Last week’s data release looks a bit paradoxical at first glance. In 2022 we registered (near) record-high birth numbers, leading our maternity wards to be busier than ever. Meanwhile the birth rate dropped to record lows.

In 2022 Australia registered 301,000 births – that’s only four per cent below the all time high of 2018, when we recorded 315,000 births. No birth-related profession will have complained about boredom in the last decade. Nurses, midwives, obstetricians and the like are all terribly busy.

We were holding the total number of births more or less steady while we grew the population at fast rates. This means we must made fewer babies on average.

The technical terms we use here are total fertility rate (average number of children born to a woman over her lifetime) and birth rate (number of live births per 1,000 residents).

These two measures can be confusing since in common parlance birth rate is often used when talking about the total fertility rate. From a macro perspective it doesn’t matter which definition we use since the trends stay the same.

I prefer the total fertility rate (TFR) since it’s so easy to compare to your own life. My mum had three kids, I am awaiting my second kid – easy to understand.

From 1934 to 1961 the TFR only went up and topped out at 3.5 kids per woman. This is why the Baby Boomer generation (1946-1963) is as big as it is.

In 1961 the contraceptive pill was introduced to Australia and births dropped immediately. In 1975 no fault divorce led to further drop in births as unhappy couples split up instead of adding more kids to the family. That’s why Gen X is such a small generation.

From the 1970s on, a slow but steady decline was only interrupted by a temporary baby blip (around 2004-14). Some people still claim that this blip was due to the baby bonus and people following then-treasurer Peter Costello’s call to have “one for mum, one for dad, and one for the country”.

The mini baby boom was not driven by a one-off cash bonus. In Scandinavia these bonuses led to mini birth spikes, but women did not end up having more babies overall.

At best, a baby bonus can bring forward a birth, it can’t trigger births that wouldn’t have occurred otherwise. Better save our dollars for more effective subsidies such as free childcare with better educated staff.

I hope you didn’t expect to see a corona baby boom in this chart. As if the only thing we could think of when we were locked up was to procreate.

While it was fun to joke about this at the start of the pandemic, demographers knew that during historic pandemics and in times of economic uncertainty people always had fewer rather than more kids.

The TFR now dropped to 1.63 kids per woman. That’s well below the replacement rate of 2.1 and hinted at the need for migration if Australia wanted to continue to grow its population base.

About two-thirds of national population growth already comes from net overseas migration rather than natural increase (births minus deaths).

The trend towards fewer births per woman is universal across Australia but the trend varies across the nation. The ACT always recorded the lowest fertility rate in the country. I would argue that’s the case because the territory is full of highly educated, career oriented people who will eventually start their families back in their home states.

Are you impressed that I didn’t attempt to make a cheap Barnaby Joyce joke at this stage? I truly am a master of restraint!

One reason why we have fewer kids is that we start families later in life – there just isn’t enough time left to make heaps of babies. A more highly educated female population (Australian women outperform men in primary, secondary, and tertiary education) and a much higher female workforce participation rate are also linked to smaller families.

Add to this freakishly high childcare costs, and a housing affordability crisis and it becomes obvious that having a large family is simply not an option for most Australians.

While examples of extreme age gaps in couples receive outsized media attention, the age gap between mothers and fathers has been shrinking. If I had to take a guess, I would say that’s because more people go to university (an ideal dating pool) where they are surrounded by people roughly the same age.

Dating apps allow you to set narrow filters and it appears people put more emphasis on age online than in a pub when you can only eyeball a stranger’s age.

Out last chart for today takes a bit to digest but it contains big shifts in fertility. Teenage births are almost a thing of the past and have reached the lowest rate in Australian history. The fertility rate for women aged 20-24 and 25-29 also reached record lows.

The most common age bracket to give birth is now 30-34 but the trend points downwards here too. Births 35-44 are on the rise but even with the wonders of IVF we are unlikely to see a spike in the 45+ bracket. We’ve pushed the limits of biology a bit, but we aren’t defeating them.

I know that the birth of your children were (probably) more memorable than reading this column, but you have to agree that this a terribly interesting dataset to study.

Demographer Simon Kuestenmacher is a co-founder of The Demographics Group. His columns, media commentary and public speaking focus on current socio-demographic trends and how these impact Australia. His latest book aims to awaken the love of maps and data in younger readers. Follow Simon on Twitter (X), Facebook, LinkedIn for daily data insights in short format.