Poor people who reside in expensive, well-educated cities such as San Francisco tend to live longer than low-income people in less affluent places, according to a study of more than a billion Social Security and tax records.
The study, published in JAMA, the Journal of the American Medical Association, bolsters what was already well known — the poor tend to have shorter lifespans than those with more money. But it also says that among low-income people, big disparities exist in life expectancy from place to place, said Raj Chetty, professor of economics at Stanford University.
"There are some places where the poor are doing quite well, gaining just as much in terms of life span as the rich, but there are other places where they're actually going in the other direction, where the poor are living shorter lives today than they did in the past," Chetty said, in an interview with NPR.
For example, low-income people in Birmingham, Ala., live about as long as the rich, but in Tampa, Fla., the poor have actually lost ground.
Chetty and his co-authors collected more than 1.4 billion records from the Social Security Administration and the Internal Revenue Service to try to measure the relationship between income and life expectancy.
"There are vast gaps in life expectancy between the richest and poorest Americans," Chetty said. "Men in the top 1 percent distribution level live about 15 years longer than men in the bottom 1 percent on the income distribution in the United States.
"To give you a sense of the magnitude, men in the bottom 1 percent have life expectancy comparable to the average life expectancy in Pakistan or Sudan."
And where life spans are concerned, the rich are getting richer.
Since 2001, life expectancy has increased by 2.3 years for the wealthiest 5 percent of American men and by nearly 3 years for similarly situated women. Meanwhile, life expectancy has increased barely at all for the poorest 5 percent.
Among the study's findings was that poor people in affluent cities such as San Francisco and New York tend to live longer than people of similar income levels in rust belt cities such as Detroit, he said.
What accounts for the disparity isn't clear, Chetty says.
It may be that some cities such as San Francisco may be better at promoting healthier lifestyles, with smoking bans, for example, or perhaps people tend to adopt healthier habits if they live in a place where everyone else is doing it, he says.
The study suggests that the relationship between life expectancy and income is not ironclad, and changes at the local level can make a big difference.
"What our study shows is that thinking about these issues of inequality and health and life expectancy at a local level is very fruitful, and thinking about policies that change health behaviors at a local level is likely to be important," he says.
Chetty notes that the study has clear implications for Social Security and Medicare. The fact that poor people don't live as long means they are paying into the system without getting the same benefits, a fact that needs to be considered in any discussion about raising the retirement age, he says.
The study was co-authored by Michael Stepner and Sarah Abraham of the Massachusetts Institute of Technology; Benjamin Scuderi, David Cutler and Augustin Bergeron of Harvard University; Shelby Lin of McKinsey and Co.; and Nicholas Turner of the U.S. Treasury Department's Office of Tax Analysis.
STEVE INSKEEP, HOST:
In this country we're getting a more specific idea of what affects your life expectancy. One factor is money - rich people tend to live longer. Now a study explores the poor people who as a group tend to live shorter lives. The study in the Journal of the American Medical Association breaks down that big demographic group and finds that some poor people live longer than others. NPR's Jim Zarroli reports on why.
JIM ZARROLI, BYLINE: Researchers looked at a vast amount of data - more than a billion records from the Treasury Department and the Social Security Administration. They found that men in the top 1 percent of income levels tend to live almost 15 years longer than men in the bottom 1 percent. Since 2000, life spans have increased 2.3 years for the highest-income men and almost three years for the highest-income women. Life expectancy for those at the bottom hasn't increased much at all. But the data also show wide disparities from place to place, says the study's lead author, Stanford University economics professor Raj Chetty.
RAJ CHETTY: There are some places where the poor are doing quite well, gaining just as much in terms of life span as the rich. But there are other places where they're actually going in the other direction, where the poor are living shorter lives today than they did in the past.
ZARROLI: In Birmingham, Ala., low-income people are doing about as well as the rich. But in Tampa, Fla., life expectancy for the poor has actually been falling. And Chetty says the poor tend to live longest in affluent, highly-educated cities. The poorest people live longer in San Francisco than in Detroit. Why this is is unclear, Chetty says. But the data show that life spans are closely tied to behavioral factors - low rates of smoking and obesity, for instance. It may be that some cities are simply better at promoting healthier lifestyles - with smoking bans, for instance. Or perhaps people tend to adopt healthier habits if they live in cities where everyone else is doing it. At any rate, Chetty says, the data suggests that the challenge of addressing life expectancy differs from city to city.
CHETTY: What our study shows is thinking about these issues of inequality and health and life expectancy at a local level is very fruitful and thinking about policies that change health behaviors at a local level is likely to be important.
ZARROLI: Chetty says the study has implications for Social Security and Medicare. Because wealthy people live longer, they're also dependent on entitlement programs longer and ultimately cost these programs more money. Chetty says there have been suggestions that these programs be indexed to account for longer life spans. But the data suggests the gains in life expectancy aren't being shared equally. Jim Zarroli, NPR News, New York. Transcript provided by NPR, Copyright NPR.