(Undated-AP) -- Life expectancy is increasing faster than some major nations realize -- and the result could strain pension plans and other programs.
That's according to a California research firm.
If residents live as long as the researchers predict, the ratio of working people to those over 65 will be much higher than industrialized nations now project.
Researchers say by 2050, the so-called "dependency ratio" will rise dramatically in the United States, Britain and Japan.
Life expectancy estimates are used by governments to determine how much should be set aside for pension, health programs and other social spending for the elderly.
The life-expectancy estimate for Americans born in 2050 is about 83 years.