U.S. life expectancy stopped improving and even fell in the 2010s, even though real income per person continued to grow. The authors use a tool called the Preston curve—a way to show how average income and average life expectancy move together—to show that something changed after 2010. Instead of richer places becoming clearly longer-lived over time, the link between resources and longevity weakened and became more unequal across places.

The team analyzed state-level data from 1980 to 2019 and county-level data from 2000 to 2019. They matched population-weighted measures of life expectancy to logged real per capita income. (Logged income means they transformed income mathematically so that big and small changes are handled in a standard way for this kind of analysis.) Life expectancy data came from published estimates and U.S. public health sources, and income data came from the U.S. Bureau of Economic Analysis. The county analyses use decadal years—2000, 2010, and 2019—so they avoid the later COVID-19 years.

Before 2010 the usual pattern held: as places became richer, life expectancy tended to rise. After 2010 the pattern broke. Places kept getting richer, but life expectancy stopped rising and in many places fell. The Preston curves moved right (toward higher income) without moving up (toward longer life). The curves also became steeper, meaning that differences in life expectancy by income grew. The authors describe this as “decoupling” (income growth no longer leading to broad longevity gains) and “divergence” (greater inequality in life expectancy across places).

The result is not limited to one subgroup. The pattern holds when the authors use different time anchors around the Great Recession and when they substitute education for income. It also appears across sex and racial groups in their state-level analyses. County-level decompositions—statistical descriptions of underlying factors—are broadly consistent with the idea that many places experienced common social problems that hurt health, a possibility the authors call “social deterioration.” Importantly, the paper is diagnostic: it highlights the change in the income–longevity relationship but does not single out one definitive cause.