Theresa is 65 years old. She has a plot in her community organic garden, hosts sleepovers for her granddaughter and has been known to dip into the world of Internet dating. She’s still working a few days a week as a freelance book editor. Mona, also 65, uses a walker and just had an arthritic shoulder replaced. She’s fully retired, on multiple prescriptions and prefers to watch TV or read. These women are the same chronological age, but their differing physical and social experiences highlight the problem in using just one number to define people.
In many countries around the world, age 65 is used as an arbitrary cutoff as “old age,” the number used to determine things like pension age and for access to health care systems. It’s also how statisticians determine a demographic measurement called “old-age dependency ratio,” which assumes everyone over 65 is depending on everyone between the ages of 20 and 65.
A new study in the journal Population and Development Review suggests that defining people as “old” at age 65 no longer fits our modern era, with many of us living longer, healthier lives. The new study pulls together a collection of demographic methods that replace the old-age dependency ratio for a variety of purposes, which should provide more useful information for policymakers.
“There are better measures available for every aspect of population aging to which it is applied,” wrote study author Warren Sanderson, of the International Institute for Applied Systems Analysis. “Aging is a suite of multidimensional phenomena. In this study we deal with a number of aspects of aging and show that better measures exist for all of them [than the number 65].”
The study proposes, for example, a health-care specific calculation that takes into account how much later people are dying because of the increase in life expectancy. Older projections of health care costs use age 65 as the cutoff, massively overestimating the future costs of a health care system. The study also included a proposal for new pension payout structures, to make things more equitable across all generations.
These new approaches to measuring how a population ages can help us more accurately plan for 21st century conditions.
Kathryn Drury Wagner is a writer and editor based in Los Angeles. Her latest book is Hawaii’s Strangest, Ickiest, Wildest Book Ever!