No place for a child

In many countries, fertility is highest in rural areas, middling in small towns and suburbs, and lowest in the cores of large cities. Though it may be hard to believe amid all the Bugaboo prams and bulging primary schools, inner London has a fertility rate of 1.5, compared with 2 in outer London. Of course, many people move to suburbs and small towns to have children.

It might be that city-center property prices have risen so high that urbanites feel they cannot afford to allocate space to children. It might be that the amenities of spruced-up inner cities are now so great that the opportunity cost of childbearing (all those nice restaurant meals forgone) is intolerably high. It is also likely that emerging patterns self-reinforce. People living in suburbs with lots of babies are encouraged to have babies; people in childless areas are more likely to skip procreation entirely. “Fertility is contagious,” says Hill Kulu of Liverpool University, an expert on this matter.