Precisely how long someones life expectancy in the United States may possibly depend upon exactly where he or she lives, along with income. This research published online by JAMA, shows that from 2001-2014 people with an excess of expendable income than the norm are expected to live longer due to available resources.

Previous research has revealed a link between higher incomes and longevity, but the more complex picture is far from complete.

It remains unclear, for example, how the gaps between socioeconomic groups are changing over time, and what effect living in a specific place has on life expectancy.

The roles played by inequality, socioeconomic stress and differences in access to medicine are also subject to debate.

An additional question is whether a threshold exists above which additional income no longer makes a difference, or if there is an income level below which the impact on health does not continue to worsen.

Researchers, led by Raj Chetty, PhD, of Stanford University in California, have examined data enabling them to estimate life expectancy at 40 years of age by household income percentile, gender and geographic location. Location was based on “commuting zones,” of which there are 741 in the US, each composed of several counties.