Of course it may well be the case that there is no alternative to the old and infirm running nations in which the average age keeps falling to the 20s and lower, but it is a debate that will not go away.

BBC: African viewpoint: Death on the continent

Every year influenza kills 36, 000 people in the U.S., mostly the very young, very old and very infirm.

FORBES: Broken Eggs

Dr Cook-Deegan was one of the authors of a study that showed a significant risk of adverse selection in the market for long-term-care insurance (the sort bought by the young in order to ensure they have nursing care when they become old and infirm).

ECONOMIST: Genetics, medicine and insurance