Baby boomers are expected to live longer than their predecessors, making them anxious about retirement.
Although people say they are happiest when they grow up, many baby boomers, born in the 1940s and 1960s, feel pressured to work longer to support themselves, or, if they can't work, worry that their savings will overspend.
Earlier this year, a survey by the Insured Retirement Institute, a retirement industry association, showed that only 23% of baby boomers thought their savings would last until retirement, or that they were ready to retire. Only 54% of people have retirement savings, and only 40% try to figure out how much they need to retire.
The survey also found that about 60% of baby boomers think their retirement income can cover basic expenses and leave some extra money for travel and entertainment - an idea that could lead to a shortage of money for baby boomers.
Some people work longer hours, but that's not everyone's choice.
To solve this problem, some Americans work until they are in their 70s, or at least part-time. But for everyone approaching the traditional retirement age, extending working hours is not a realistic choice.
The employment market is in a transitional period, and many roles are being automated, especially in manufacturing enterprises. For those who lose their jobs in old age, learning new skills or returning to school is not always easy. At the same time, physical labor is often difficult for the elderly.
Therefore, those who plan to retire from the mid-1960s to the early 1970s need enough money to save 10 to 20 years more than in the past.
Larry Fink, chief executive and chairman of BlackRock, said in an annual letter to shareholders earlier this year that longevity was "one of the biggest financial challenges facing our customers today".
He described longevity as an undervalued factor in American economic anxiety.
But it's not just America's problem.
Crucially, it's not just a problem for the United States, it's not even a new one. After observing for some time, economists found that fewer children were born than the number of older people in the world.
A Census Bureau forecast shows that older people will begin to outnumber younger children in the years to 2020.
This trend is likely to continue. The Census Bureau estimates that by 2050, the population aged 65 and over will account for 15.6% of the global population, more than twice the number of children aged 5 and under, and an estimated 7.2%.
If these predictions are valid, the number of retired elderly people will increase dramatically, and the number of eligible citizens working around them will be far less than that of the elderly, which may bring another problem to longevity.
This article first appeared on businessinsider.com.