Projected international population change

If you have not yet watched the documentary by Shaw (2025), Birthgap, I strongly recommend it. I felt it connected many disparate elements for me in understanding why so many of us are not having children.

For population stability, our replacement rate needs to be 2.1. However, with replacement rates at 1.50, the UK is well under that (Economics Help UK, 2024, 1:15), and quite similar to the population replacement rate in Aotearoa New Zealand, at 1.52 (Spoonley, 2024). Further, the UK replacement rate is projected to drop to 1.2 by 2050, leaving one person working for every retiree (Economics Help UK, 2024, 5:18). Crikey. Imagine the impact of having only one taxpayer for each retired person!

There are a number of drivers attributed to our population reduction: the cost of raising children; the cost of housing; access to family planning; the increasing percentage of women in the workforce; and climate change (Economics Help UK, 2024; BBC, 2025). Additionally, market research indicates that our stated drivers - such as finance - may not really be survey participants' 'real' reasons: often what we attribute our choices to may be masked by finer, complex, societal nuances. For example, the documentary (Shaw, 2025) showed what a big player global crises are in young people either getting into relationships, or postponing parenthood, by illustrating the number of Japanese who postponed having children due to the oil shocks of the mid-1970s. A similar drop in birthrate followed the global financial crisis of 2007 (Shaw, 2025, 21:09), and - as I understand it - has followed the Covid-19 pandemic (Winkler-Dworak et al., 2024).

As well as the global shocks, culture is another likely factor, where mothers "must be prepared to sacrifice [themselves] and [their] self-interests and selfish desires" (Símonardóttir, 2024, p. 470) in order to have a family, with the pressure of excellence meaning "Inhuman stress is placed on people, especially mothers" (p. 471). And perhaps that should read "inhumane". 

I was particularly struck by how many men in the documentary seemingly indulged in magical thinking, that they still had plenty of time to get married, despite the fact that they were already in their late 30s (Shaw, 2025, an example at 1:07:00). Additionally, education is both expensive AND necessary for our children to be successful in a modern world, delaying our ability to be parents until our own educational investment/opportunity cost has generated a return.

Declining fertility is not often mentioned in other sources (Economics Help UK, 2024), however, Shaw tackles it, discovering what he calls the "vitality curve", where the intersection of new mothers and fathers by their age shows that as the age of first child increases, the fewer children are had by the parents overall (2025, 1:02:52). Really, this intersectionality should not be a surprise, but it seems to show that decisions to postpone parenthood may mean we really cannot have it all.

The most striking aspect of the documentary is our apparent individual powerlessness to reverse this trend (Shaw, 2025). This will take a whole-of-society approach, and I worry that we have little political will to do that... even more so because those of us who are older are still voting, and who is going to vote themselves out of their own 'well-earned' retirement?

Are we self-less enough?

Sam

References:

BBC News. (2025, August 12). How will falling birth rates affect the global economy? | BBC News [video]. YouTube. https://youtu.be/goVElusmeac

Economics Help UK. (2024, August 5). Why UK Population Is Set to Fall Much Faster Than Forecast [video]. YouTube. https://youtu.be/I5kcbEK-qAc

Shaw, S. J. (Writer, Director, Producer). (2025, September 19). Birthgap [documentary film, Torch Pictures]. YouTube. https://youtu.be/m2GeVG0XYTc

Símonardóttir, S. (2024). “Unless I could be like the typical dad”: Exploring parenthood through the perspective of the voluntarily childfree. Acta Sociologica, 67(4), 463-477. https://doi.org/10.1177/00016993241260608

Spoonley, P. (2024, May 27). NZ is changing faster than the census can keep up – the 4 big trends to watch. Radio New Zealand. https://www.rnz.co.nz/news/political/517937/nz-is-changing-faster-than-the-census-can-keep-up-the-4-big-trends-to-watch

Winkler-Dworak, M., Zeman, K., & Sobotka, T. (2024). Birth rate decline in the later phase of the COVID-19 pandemic: the role of policy interventions, vaccination programmes, and economic uncertainty. Human Reproduction Open, 2024(3), hoae052. https://doi.org/10.1093/hropen/hoae052