Q. Education, you say, "has replaced the big family as the world's insurance for old age." How so?
A. When urban families decide to have fewer children, they do so for a classic reason — children are a liability, not an asset. They cost money. They don't support you by working the family farm. But if you have fewer children, you can invest more in their education. And when you do, you almost ensure that they'll have a small family themselves, because their education takes time. Add all of that together, plus the fertility window that closes on women, and you have this family investment. A person can earn enough to help pay for care and save for their old age themselves. It's a kind of double insurance.
Q. Decent health coverage, of course, will remain critical. How does that figure into the scenario you just mentioned?
A. Bad things do start happening to very large numbers of people in their 60s and 70s. So even while we can focus on a big group of the older population as being able, dynamic, wonderful and inspiring, we have to acknowledge that there is also a very, very large group that is dependent. They may not be completely dependent — they may be able to have fine lives — but a fine life is not the same as a life that's economically valuable in the workplace.