COLUMBUS, Ohio – A new study provides the best evidence to date that higher levels of income inequality in the United States actually lead to more deaths in the country over a period of years.
The findings suggest that income inequality at any one point doesn’t work instantaneously – it begins increasing mortality rates 5 years later, and its influence peaks after 7 years, before fading after 12 years.
“This finding is striking and it supports the argument that income inequality is a public health concern,” said Hui Zheng, author of the study and assistant professor of sociology at Ohio State University.
The study appears online in the journal Social Science and Medicine and will be published in a future print edition.
Many other studies have examined the impact of income inequality on mortality and have come up with mixed results, according to Zheng. But he thinks that this study overcomes problems in previous research by using a different data structure and statistical model (called a discrete-time hazard model).
Zheng used data from the U.S. National Health Interview Survey from 1986 to 2004 with mortality follow-up data from 1986-2006. His final sample included more than 700,000 people aged 30 and up.
The study measured income inequality using three different methods, including the most commonly used metric – the Gini coefficient, calculated by the U.S. Census Bureau. All three methods resulted in similar findings.