In Japan, there are now companies that specialise in cleaning the apartments of elderly people who have died alone and gone undiscovered for weeks or months, while adult incontinence pads have outstripped nappy sales for more than a decade. In Italy, depopulating villages are selling homes for €1 to attract new residents and keep services running. In the UK, falling pupil numbers are already closing schools and classrooms in parts of London.

These are not isolated curiosities, but signs of a broader shift taking place across much of the developed world. “In the EU in 2024, 21 of 27 countries had more deaths than births,” said Prof Sarah Harper, the director of the Oxford Institute of Population Ageing.…