Dartmouth Study Links State Tax Spending to Middle-Aged Mortality Rates

There is a strong association between the amount that U.S. states spend on their residents through statewide taxation and state government expenditures and middle-aged mortality rates, according to a new Dartmouth study in the journal PLOS One.

Todd MacKenzie, PhD (photo by Rob Strong)

Despite spending more on healthcare per capita than any other country, the U.S. ranks lower than many other Western nations in longevity, which is positively associated with social welfare according to cross-national studies. And while mortality has been decreasing around the world for some time, this trend toward improvement has stalled in the U.S.

“There is less government-sponsored welfare, education, and healthcare in the U.S. than in nearly all other Western countries, though the amount that states spend in support of these services differs across the country,” explains lead author Todd MacKenzie, PhD, a professor of biomedical data science and of The Dartmouth Institute for Health Policy and Clinical Practice. “This variation in tax burdens and government expenditures provided us with an opportunity to explore their association with mortality.”

The researchers measured primarily the tax burden—defined as the proportion of all state income paid to each state—but also local government expenditures per capita on education, welfare, health and hospitals, highways, and police for each state in 2005. They then correlated mortality rates for all residents (ages 40 to 64) in each state for the subsequent 10 years (2006-2015).

“We were able to conclude that the residents of states with higher state taxation and higher expenditures per capita have lower middle-aged mortality rates,” says MacKenzie. “Our study is the first, to our knowledge, that links mortality to state taxes and expenditures using data on all middle-aged deaths in the U.S.”

The investigators found that the state tax burden varied from nearly 6 percent to about 12 percent in 2005. An increase of one percentage point in state tax burden was associated with about a 6 percent reduction in mortality, after adjusting for sex, age, and race, but was associated with about a 1 percent reduction with further adjustment for state income and education levels.

“Considering this era of American mediocrity in longevity and the recent federal tax cut, the role of state government expenditures on population mortality and morbidity requires scrutiny,” says MacKenzie, who is now working on a similar analysis at the city level.

“If the federal government reduces expenditures on health, welfare, and education, mortality may increase,” he says. “So, states may want to look at increasing their financial commitment in these areas. However, more work is needed to determine the relative contributions of each type of expenditure on mortality and other health outcomes.”