Social Security overestimates death rates: study

WASHINGTON (Reuters) - The U.S. Social Security Administration, which pays out $600 billion a year in benefits to retirees, may have underestimated how a decline in smoking will increase life expectancy, two experts reported on Monday.

Haidong Wang of the University of Washington in Seattle and Samuel Preston of the University of Pennsylvania said their calculations showed that by 2035 a man's odds of surviving from age 50 to age 85 will be 22.5 percent greater than projected, and a woman's odds more than 7 percent greater.

This could affect the Social Security Administration's budget, which now calculates that by 2034, 74 million Americans over the age of 65 will be living, compared to 38.6 million now.

"What may be bad news for the fiscal balance of the Social Security system is good news for the population as a whole and especially for men," they wrote in the Proceedings of the National Academy of Sciences.

"Because of changes in smoking behavior that have already occurred or that can be reliably projected, American mortality is likely to fall more rapidly than is commonly anticipated."

In November, the U.S. Centers for Disease Control and Prevention reported that the U.S. adult smoking rate fell below 20 percent for the first time on record. It was 42 percent in 1964.

Smoking and secondhand smoke kill 443,000 people annually from cancer, lung disease, heart disease and other causes, the CDC says. Half of all long-term smokers, especially those who start as teens, die prematurely, many in middle age.

"Although epidemiologic studies have identified cigarette smoking as an important risk factor in mortality for at least a half century, there is no consensus on how great the risk is," Preston and Wang wrote.

They noted that an American Cancer Society study showed that white male smokers aged 40 to 84 were 91 percent more likely to die than non-smokers and white women 46 percent more likely to die than non-smokers.

When they took into account the drop in smoking rates, Preston and Wang projected that mortality rates would fall more quickly by 2034 than the Social Security Administration has predicted.

The government projection gives a 50-year-old man only a 39 percent probability of living to age 85 in 2034, compared to Wang and Preston's estimate of 57 percent.

(Reporting by Maggie Fox; Editing by Julie Steenhuysen and Eric Beech)