Aha, Jim lad!

At 108, Okushima takes to the floor for traditional Japanese dances. She was born when Japan had only recently seen off the shogun warlords. If an ageing population is on the way, she is not a bad advert for what we have in store.

In 1984, Japan had the youngest population in the developed world, but by 2005 it had become the world's most elderly country. Soon it will become the first country where most people are over 50 years old.

The fertility rate in Japan is just 1.2 children per woman, far lower than the 2.1 needed to maintain a steady population. And they're not alone. In 19 countries, from Singapore to Iceland, people have a life expectancy of about 80 years. Of all the people in human history who ever reached the age of 65, half are alive now. Meanwhile, women around the world have half as many children as their mothers. And if Japan is the model, their daughters may have half as many as they do. In just a generation, world fertility has halved to just 2.6 babies per woman. In most of Europe and much of east Asia, fertility is closer to one child per woman than two, way below long-term replacement levels. The notion that the populations of places such as Brazil and India will go on expanding looks misplaced: in fact, they could soon be contracting.

The long term implications are significant, because we're acquiring a population of older, very experienced, intelligent people who have time on their hands and a desire to fill that time with productive but non-stressful occupations.  Thus we have ex-Police superintendents stacking shelves at Tesco, ex-senior social work managers selling boots and shoes, ex-lecturers serving coffee and ex-nuclear physicists looking after trees. These people comprise an enormous resource for the country in terms of skills, knowledge and experience, and it will be interesting to see which of the main parties promises to use that resource for the UK.