After the increase in child survival, the other major demographic change to come from the doubling of average human lifespan is a robust population of old people. In 1850, the proportion of people age 60 or older in the United States was about 4 percent. Today they account for about 20 percent of the population.Now, to be sure, increases in longevity (not lifespan--that's fixed by biology) lead to increases in the NUMBER of older people, but it is the drop in fertility that leads to the increase in the PERCENT of the population that is older. She seems to understand that point, however, because in the next paragraph she says:
Economists fret about declining birth rates in the developed world and the challenge of financially supporting large elderly populations. But old people are awesome. Having a high ratio of older to younger people isn’t just a consequence of living in peace and prosperity—it’s also the foundation of a civilized society.
Old people aren’t merely less bellicose and impulsive than young people. They’re also, as a group, wiser, happier, and more socially adept. They handle negative information better, have stronger relationships, and find better solutions to interpersonal conflicts than younger people do.As a parent and a grandparent, I have to say 'yes' to that. Stop worrying about whether or not there are too few young people and revel in the older population. They won't be around for ever, you know.