A person entering the workforce today in America might face a much longer career than Mom and Dad.

Life expectancy in the United States is now around 78 years. But if anti-aging therapies prove to work as well for humans as they have for worms, flies, and mice in laboratories, by the year 2050 people might routinely reach the ripe old age of 120.

That could place a tremendous burden on the economy if people continue retiring at 65 or earlier.

The retirement age might have to be boosted to 85 to prevent economic collapse, figures Shripad Tuljapurkar of Stanford University.

Do the math

There are 285 million people in the United States, with the median age around 36. Every two people over the age of 65 depend on money garnered from the wages of 10 working people age 20 to 65.

If current trends continue, by 2050 the population will be 368 million, the median age will be 43, and there will be 3.6 people over 65 per 10 workers, Tuljapurkar explained here last week at the annual meeting of the American Association for the Advancement of Science.

Those are the conservative estimates, based on data from the last 50 years, when life expectancy increased by one-fifth of a year per year in industrialized countries.

What if ...

Scientists around the globe are racing to find aging cures. Some of the work on lab animals has shown great promise.

One researcher envisions therapies will be developed over the next 25 years to extend life hundreds of years. Other scientists imagine more modest gains.

Gradually, however, aging is being viewed by many as something that can be largely treated.

If anti-aging therapies come into play around 2010 — and no one can accurately predict if they will — Tuljapurkar estimates that the U.S. population will run to 440 million people, a median age of 47, and 6.6 persons over 65 will rely on 10 workers.

"What you would need to do is have people retire somewhere between age 75 and 85," Tuljapurkar said.

Increasing the retirement age to 75 would still yield four retired persons per 10 workers in this scenario. A better solution, Tuljapurkar said, would be to have people retire at 85.

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