From BernardLietaer's book :

How will we provide for so many elderly?

It can be done, but not through normal economic means. In fact, it IS being done. Since 1995, the Japanese organization Sawayaka Welfare Institute (a privately run citizen's group) has been implementing a special currency called Hureai Kippu ("Caring Relationship Tickets"). Here's how it works: About 100 different non-profit organizations in Japan have agreed to use this complementary currency. To become involved, you perform some service for someone who is elderly–perhaps food shopping, or housecleaning, or whatever they need. As you provide services, you accumulate credits. You can either use these credits yourself, when you sick, or when you get old, or give them to your parents, who may even live in other parts of Japan (the program is very widespread). You can even redeem and manage these credits on-line. This program provides value where there was none before. Plus it has one wonderful side-effect: because people are volunteering their time, and there is no profit-motive, the elderly report they like this kind of care better than any other. By using complimentary currency, people in Japan have better care, more hope for good care in their old age, better relationships, and more involvement in each other's lives. Such systems could work all over the world, and be a real solution to the "age wave" that the world is going through.