The New Old Age

America is growing older. We knew that. But earlier this year, the U.S. Census Bureau quantified how much older and how fast it will happen. The numbers paint a picture of a nation on the brink of remarkable change.

Today, about 13 percent of Americans are over age 65. By 2030, more than 20 percent of Americans will be in that group. By 2050, about 89 million Americans will be over age 65, more than double the number today.

By 2025, the number of centenarians will more than double to 175,000, from fewer than 80,000 now.

By 2035, the number of people ages 85 and over will double to 11.5 million, from about 5 million now.

Still, the U.S. population overall will not be as elderly as these statistics might suggest. The nation continues to attract large numbers of immigrants, who tend not only to be younger but also to have higher birthrates. As a result, the proportion of working-age people who are employed and pay taxes to support others, both younger and older, will be higher here than it has been in Europe and Japan, where proportions of working-age citizens have declined. …