JAPAN has the oldest median age in the world, at nearly 43. Its wealth and a famously healthy diet keep its people going to a ripe old age, while a low fertility rate means fewer young people to redress the balance. Europe accounts for the other nine countries in the top ten. Germany and Italy both benefit from generous pension and healthcare systems, coupled again with fewer babies. Bulgaria and Croatia, on the other hand, probably owe their rankings to the outflow of their young to find work.

EPA