The Changing Link Between Income Inequality and Mortality

by Jon Scaccia December 12, 2024

For decades, the relationship between income inequality and mortality shaped conversations about public health. Early studies in the 1980s and 1990s found a strong connection: as income inequality rose, mortality rates climbed. But new research spanning 30 years—from 1989 to 2019—flips this script, challenging long-held beliefs and offering fresh insights for public health practitioners.

Let’s break down the findings, explore their implications, and consider how this knowledge could reshape public health strategies.

Income Inequality and Mortality: Then and Now

In 1989, the data was clear: income inequality, measured using the Gini coefficient, had a direct link to higher mortality rates. A small increase in inequality translated to a significant rise in deaths. For example, working-age males in states with a higher Gini coefficient experienced nearly 30 more deaths per 100,000 people. The story was similar for working-age females, with a smaller but still notable increase.

Fast forward to 2019, and the story takes a surprising turn. The same increase in income inequality now correlates with fewer deaths among both working-age men and women. The once-strong positive relationship between inequality and mortality had not only faded but in some cases reversed. States that experienced greater increases in income inequality during this period often saw sharper declines in mortality rates.

Why Did This Shift Happen?

The research doesn’t provide all the answers but offers compelling clues:

1. Protective Factors in Wealthy States
   States with high-income inequality often have higher median incomes. These wealthier states may have invested more in public health, education, and infrastructure, helping buffer residents from the adverse effects of inequality.
2. Evolving Mortality Trends
   Between 1989 and 2019, mortality trends in the U.S. shifted dramatically. For example, working-age mortality initially declined in the 1990s but began rising again after 2009, particularly in states with lower income levels.
3. Health Behaviors and Policies
   High-income states have increasingly diverged from their lower-income counterparts in terms of health behaviors and policy initiatives, such as expanded healthcare access, smoking reduction programs, and nutrition interventions. These policies may mitigate mortality risks, regardless of income inequality.

What Does This Mean for Public Health?

These findings disrupt the traditional narrative that income inequality is an inherently harmful force on health. Here are three key takeaways for public health practitioners and policymakers:

1. Focus on Proven Interventions
   While reducing income inequality remains a worthy goal for social justice, this study suggests it may not be the most direct lever for improving population health. Instead, prioritizing interventions like access to healthcare, income support, and health-promoting policies could yield more tangible results.
2. Investigate Protective Factors
   States with high inequality but declining mortality provide valuable lessons. What are they doing right? Understanding these protective factors could guide strategies in less-advantaged regions.
3. Tailored Policy Approaches
   The relationship between inequality and mortality isn’t universal—it depends on context. Policymakers should avoid one-size-fits-all solutions and instead adapt strategies to the specific needs and conditions of their populations.

Urgency in Action

The stakes couldn’t be higher. Working-age mortality rates, particularly among vulnerable populations, continue to rise in some states. To reverse these trends, public health leaders must focus on evidence-based, scalable interventions. Meanwhile, researchers should deepen their investigation into why some states fare better than others and how inequality interacts with other social determinants of health.

Time is of the essence. If states with rising mortality rates fail to act, the gaps in life expectancy between regions will continue to grow, further entrenching health disparities.

What Can Public Health Practitioners Do Now?

And look, I know all of these are easier said that done.

1. Invest in Public Services
   States should prioritize access to healthcare, mental health services, and substance abuse treatment, especially in areas with high mortality rates.
2. Strengthen Community Resilience
   Public health leaders can support community-driven programs that enhance social cohesion, provide job training, and increase educational opportunities—factors that improve health outcomes even in unequal societies.
3. Advocate for Data Transparency
   Better, more frequent data on inequality, mortality, and social policies can empower policymakers to act swiftly and effectively.

Join the Conversation

What do you think about these findings?

• Are you seeing similar trends in your community or state?
• What public health interventions have you found effective in addressing mortality disparities?

Empower Your Network – Subscribe and Share!

Unlock key insights with ‘This Week in Public Health.’ Subscribe for free and share to drive change as part of a dedicated community. If you liked this blog, please share it! Your referrals help This Week in Public Health reach new readers.