As a kid, your older teen brother seemed so adult, and when you finally become a teen, 25 just seems so old. While old is subjective, a new study published in the journal PLOS ONE says that a new standard of aging means that 70 is really the new 60. According to the paper, aging should reflect how long people in your country are likely to live rather than actual age by birth year.

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Traditionally, old age is considered to begin at 65 years old, however, life expectancies have increased, meaning people are healthier and more active than in previous years. Researchers at the International Institute for Applied Systems Analysis, a research institute that focuses on changes in the 21st century, have published many research studies indicating that old age should adapt as a population’s characteristics change.

Additionally, the study predicts that population aging will no longer be an issue in the United States by the end of the century. Population aging occurs when there are more older people in a society for a variety of reasons, from decline in births to an increase in life expectancy.

“This study is different from previous research in that we used United Nations forecasts that take uncertainty into account and combine those forecasts with our new measures of aging,” said Warren Sanderson, PhD, a Professor of Economics at Stony Brook University and lead author, in a statement. “When this is done, it is a virtual certainty that population aging will come to an end in China, Germany, and the U.S. well before the end of the century.”

Sanderson explains that study mixed this new method of analyzing age with the United Nations probabilistic population projections for China, Germany, Iran, and the United States.

“Both of 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,” Sanderson said.

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In China, Germany, and the U.S., data revealed that population aging would peak before declining, however the same isn’t true for Iran, which experienced a steep decline in fertility rates over the past 20 years.

Not frequently discussed, population aging is an important topic that impacts almost every aspect of society. According to Brookings, population aging can lead to declining labor forces, dips in fertility and a decrease in working-age people to older individuals. All of this can cause some major challenges as more government spending will be needed for pensions, healthcare and programs for the elderly. Brookings believes these struggles can be offset by keeping older people employed longer and rewarding senior citizens for their volunteer efforts after retirement.

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