An important part of any country’s journey to modernity is the demographic transition captured in the neat epithet ‘first we stop dying like flies and then we stop breeding like rabbits’. The transition is turbulent – it involves a surge in population as a big cohort from the era of high birth rates and declining mortality works its way through society. But after getting through that process, many countries, not just in the West, reach the Goldilocks scenario of about two children per women.

In some countries, though – including Italy and Japan – the birth rate has fallen way below this because of the expectation that mothers stick to their traditional roles. If women are expected to do all the childcare and housework, and perhaps care for elderly relatives as well, they opt out of having children rather than opt out of having a job. By contrast, in countries with rights to more flexible employment and better access to childcare, such as Sweden and the UK, the birth rate has until recently been stable.

However, across the developed world birth rates are now falling. Even allowing for the distorting effects of Covid-19, in countries such as Britain and the USA the number of births has fallen well below the replacement level. Birth rates are getting even lower in countries where they were already low.