Study: For Many, Being 70 Isn't What It Used to Be

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A different way to measure population aging takes into account changing life expectancy, with implications for healthcare.

People growing older say that age is just a number, and a new study led by Stony Brook University finds plenty of truth in the idea—and some countries may have to rethink how they measure how their populations are aging.

Appearing in PLoS ONE, the study uses new measures to show that the best way to project population aging may be to adjust for how many years people have ahead of them—based on their health and other factors. Such methods take into account increased life expectancies and longer periods of productivity, rather than using age 65 as a simple cut-off.

The study by the International Institute for Applied Systems Analysis combines new measures of aging with probabilistic projections based on data from the United Nations (UN). It takes on concerns about population aging, which occurs when the median age in a country rises as life expectancy increases and people have fewer children. This is considered a problem in several developed countries, as officials worry what will happen if there are fewer workers to support those who are no longer working.


But this new study views the issue differently. Rather than viewing population only through the prism of median age, this study finds that population aging could peak and then end in several places before the end of the century.

The structure of the study combines these new measures with UN probabilistic projections to create different age outcomes for 4 countries: the United States, China, Germany, and Iran. It projects population aging could peak in 2040 in Germany and by 2070 in China. Population aging would also end in the United States before the end of the century, but not in Iran.

“Both these demographic techniques are relatively new, and together they give us a very different, and more nuanced picture of what the future of aging might look like,” Warren Sanderson, PhD, professor of economics at Stony Brook,

Such an approach has implications for healthcare in the United States. Policy leaders have fretted over what to do about the growing number of people over the age of eligibility for Medicare. In 2012, the US Census Bureau estimated the population over age 65 would nearly double from 43 million to 83 million by 2050.

The study’s approach also highlights the fact that while some people are healthier than ever into their 60s and 70s, some are not. Health policy must address the fact that some are living for decades with chronic diseases like diabetes that consume a disproportionate share of healthcare resources and prevent these individuals from enjoying the decades of productivity seen by those who stay healthy.


Sanderson WC, Scherbov S, Cerland P. Probabilistic population aging [Published June 21, 2017]. PLoS ONE. 12 (6): e0179171. DOI:10.1371/journal.pone.0179171.