The Greying Globe

The highest circulation periodical in the United States is AARP Magazine. In Japan, sales of adult diapers have outstripped baby diapers. It’s an old story: with longer lifespans, the ranks of senior citizens are swelling to unprecedented proportions. And this demographic sea change isn’t confined to wealthy countries. In fact, population aging is happening more quickly in developing countries than anywhere else.

The global scope of aging was the theme of this year’s Age Boom Academy, a three-day program organized by the Columbia Aging Center and Columbia Journalism School to bring together aging scholars and other experts with journalists who cover the aging beat.

Ursula Staudinger

According to United Nations demographer Thomas Spoorenberg, the fraction of adults age sixty or older in Sub Saharan Africa will more than triple by 2050. By comparison, the number of seniors in Europe, already an old population, will inch up a relatively modest one-third. 

What’s more, low and middle-income countries will undertake these changes at lightning speed. What took wealthy countries 150 years will happen there in 20 years, and at a lower level of economic development.

But while these facts may seem menacing, it isn’t the demographic tsunami it seems to be. Much depends on how you define your terms.

What does “old” mean? asked Joel Cohen, professor of Earth and Environmental Sciences at Columbia’s Earth Institute and professor of Populations at the Rockefeller University. Instead of thinking about how many years we’ve lived, we should look at how many years we have left to live. Case in point: Fifty years ago, an average American at age 60 could expect to live another 15 years. Today, the same thing holds true for a 70-year-old. In other words, 70 is the new 60. “This isn’t a catchy phrase for a t-shirt; this is a fact,” Cohen asserted.

Using this measure of remaining life expectancy, population aging is far less dramatic in countries as varied as China, India, and the United States. In fact, aging in Germany and Japan is already practically flat. Incredibly, it’s even possible for countries to grow “younger” as they get older, as remaining life expectancy outpaces chronological aging.

And older adults aren’t the burden they’re made out to be. Politicians and journalists often use a standard measure called the dependency ratio to paint a grim picture of aging. This method, said Cohen, is “out of whack with reality,” in part because it wrongly assumes that all adults between ages 15 and 64 are working and all adults age 65 and older are retired. People age 70, 80, and beyond can be healthy and independent.

Another way to define “old” is functional age measured by a battery of cognitive tests. This approach taken by Vegard Skirbekk, professor of Population & Family Health at Columbia’s Mailman School of Public Health and member of the Columbia Aging Center, turns conventional wisdom on its head. By the standard view, India is among the youngest nations. But by Skirbekk’s accounting, the country is effectively older than the United States because an average 50-year-old there has diminished cognitive function compared to his or her counterpart here.  

The good news: education can reverse this deficit. In a study in England conducted with Ursula Staudinger, director of the Columbia Aging Center, Skirbekk, also a senior researcher at the Norwegian Institute of Public Health, found that growing investments in education improved cognitive abilities of older Brits generation to generation.  

The 20th century may have been the last century with more young people than old people. Now we are on the verge of an unprecedented age distribution—one that resembles a column instead of a pyramid with equal numbers in each age bracket. But societies need to make the most of this change, said Staudinger, with investments in social development across all life stages. “The potential upside for humanity is huge.”