The effects of depopulation are going to provide some of the more interesting social, political and cultural phenomena of the late twenty-first century. As women’s literacy has increased, so birth rates have declined across western economies. Anyone who has watched someone go through pregnancy can figure out why. Women are voting with their fertility.

So how do I persuade my children that they too need to keep the genetic faith? Is just keeping on keeping on sufficient?Some of this stuff is in my book, Crunch Time (see column opposite), and it came hurtling back to me through two things. One was a post by the ever-thoughtful Seamus McCauley:

rather than embark on the expense and inconvenience of bringing up children the ageing populations of the developed world are simply selling off their countries to inbound workers in return for the promise of lifetime pensions and healthcare.

Also, because perceptions of wealth and poverty are relative, as it becomes increasingly normal not to procreate those who choose to do so will find themselves relatively impoverished compared to the observable childless norm. It’s an extraordinary picture of a vicious circle of demographic decline with no clear way out.

The other was the political impact of ex-patriates on elections in Spain. Nation states that want the media to prop up their sense of community will find demographics slipping away from them.

Rising social fragmentation and lower fertility are the new facts of life. And that will have consequences for journalism too.