Join the one per cent and live a decade longer

Plenty of research has already shown that health and wealth are intertwined, and that they generally improve in tandem as one move up the income scale

The wealthiest Americans can expect to live at least a decade longer than the poorest-and that gap, as with income inequality, is growing ever wider.

New research in the Journal of the American Medical Association (JAMA) shows top earning Americans gained 2 to 3 years of life expectancy between 2001 and 2014, while those at the bottom gained little or nothing. Plenty of research has already shown that health and wealth are intertwined, and that they generally improve in tandem as you move up the income scale. But this year, wildly divergent incomes among Americans and the vanishing middle class have been central issues in a vitriolic race for the White House. Today's JAMA research shows in the starkest terms yet how disparities in wealth are mirrored by life expectancy, and how both are getting worse.

Research last year showed that mortality rates are rising among middle-aged whites, largely due to suicide, drug overdoses, and alcohol. That work, by Princeton University economists Anne Case and Nobel Prize winner Angus Deaton, reflected economic stresses on working class whites that have in turn fueled the ascendancy of Republican Donald Trump and his populist message. The latest paper reinforces the idea that inequality in the US, the issue that's also driven Sen. Bernie Sanders' campaign on the Democratic side-has consequences beyond wealth and income.

Take a 40-year-old man in the top 1 per cent. He can expect to live, on average, to 87. His counterpart in the bottom 1 per cent would be expected to perish, on average, before his 73rd birthday. For women, who live longer on average, the gap was narrower, but still substantial. Life expectancy for the richest women is almost 89, about 10 years longer than the poorest.

The authors-economists from Stanford University, the Massachusetts Institute of Technology, Harvard University, consulting firm McKinsey & Co, and the US Treasury's office of tax analysis-used anonymous Internal Revenue Service data from 1.4 billion tax records over 15 years and matched them to death records from the Social Security Administration.

The change between 2001 and 2014 shows that the wealthy are benefiting more from gains in longevity than the destitute. Men among the top 5 per cent of earners gained more than two years and women gained almost three. In the bottom 5 per cent, life expectancy for men only increased by a few months, and for women, hardly at all.

When the researchers looked at how life expectancy changed by geography, there were some bright spots. Among the bottom 25 per cent of incomes some regions had longevity gains of more than four years, while others lost more than two years. The differences "suggest that the increasing inequality in health outcomes in the US as a whole is not immutable," the authors write. The shortest life expectancy in the poorest quartile was in Oklahoma and rust belt cities like Gary, Indiana, and Toledo, Ohio. The longest was in cities like New York and San Francisco, with "with highly educated populations, high incomes, and high levels of government expenditures."

The geographic differences in life expectancy for low-income people weren't strongly explained by access to health care, unemployment rates, or housing segregation, the authors write. Instead, lifestyle and behaviour were at work: smoking, obesity, and exercise.