That’s according to a comprehensive new study by Stanford University economist Raj Chetty and his colleagues, published Monday in the Journal of the American Medical Association. In it, the researchers find that, yes, the richest Americans generally tend to live much, much longer compared to the poorest ones; but their longevity doesn’t depend on geography. How long poor Americans tend to live, however, varies drastically based on where they live.
The researchers dug into 1.4 billion anonymous tax and mortality records from between 1999 and 2014. From these data, they estimated the remaining life expectancy of people at 40 years of age, adjusted for racial and ethnic disparities. They found that the top 1 percent of women and men tended to live around 10 and 15 years more, respectively, than their counterparts in the bottom 1 percent. What’s more, the rich folks had larger gains in longevity between 2001 and 2014 (3 years) than poor Americans (1 year). Here’s some context on those numbers, from the report’s summary:
The poorest men in the U.S. have life expectancies comparable to men in Sudan and Pakistan; the richest men in the U.S. live longer than the average man in any country.
But the most striking finding came when researchers broke down longevity estimates by “commuting zones.” (These are clusters of counties whose residents tend to commute to the same city in the region for jobs. They’re sort of like metros, but also include rural areas, and are generally named after the biggest city in the zone.) Those at the bottom of the income spectrum could see around a 5 year difference in their life expectancy, depending on their city. That variance vanished up the income ladder (see the chart below).
And here’s what that map looks like for women:
These differences are even more stark when you compare commuting zones. The poorest residents of Birmingham, Alabama, for example, gained the same average number of years in life expectancy (3.7) between 2001 and 2014 as the richest. In Tampa, Florida, on the other hand, life expectancy for the poor decreased by 2.2 years in this period.
The study found that life expectancy generally correlated negatively with rates of smoking, obesity, and lack of exercise, “suggesting that any theory for differences in life expectancy across areas must explain differences in health behaviors.” On the other hand, factors such as access to health care, residential segregation, and unemployment weren’t strongly related with life expectancy per Chetty’s research. (That doesn’t, however, necessarily mean that these conditions don’t affect life expectancy at all, and that improving them won’t make a difference.)
The areas where poor Americans tended to live the longest were those with high average incomes, high levels of education, and high government expenditure. A number of potential reasons could explain these positive correlations. Some of these cities may have policies that discourage smoking and sugary drinks and encourage exercise, for example. They may also have more public health services that low-income residents can take advantage of. On the other hand, poor populations in these places might differ from those in other cities: New York, for example, is home to more immigrants, who tend to live longer than native-born Americans.
One thing is for sure, though: Local interventions seem to make a difference. Here’s what the researchers conclude, from the report:
Our findings show that disparities in life expectancy are not inevitable. There are cities throughout America—from New York to San Francisco to Birmingham, AL—where gaps in life expectancy are relatively small or are narrowing over time. Replicating these successes more broadly will require targeted local efforts, focusing on improving health behaviors among the poor in cities such as Las Vegas and Detroit.