Ageing planet: the new demographic timebomb

Elderly residents exercise in a Beijing park. China last week announced its population had fallen for the first time since the 1960s. Photograph: Dan Chung/The Guardian

In Japan even criminals are getting old. In the country’s notorious yakuza crime syndicates, more than half of members are now over 50, according to the national police agency.

Veterans who have passed 70 outnumber those in their 20s by two to one, even though younger men are the groups’ traditional source of “muscle”.