I feel that you are misrepresenting the study here. The conclusions from the abstract: In the United States between 2001 and 2014, higher income was associate

I feel that you are misrepresenting the study here. The conclusions from the abstract: In the United States between 2001 and 2014, higher income was associated with greater longevity, and differences in life expectancy across income groups increased over time. However, the association between life expectancy and income varied substantially across areas; differences in longevity across income groups decreased in some areas and increased in others. The differences in life expectancy were correlated with health behaviors and local area characteristics. The figure you point to absolutely does not say that income inequality does not have a significant effect. Figure 8 shows that the association between life expectancy and income varied substantially across areas; differences in longevity across income groups decreased in some areas and increased in others. So yes, the differences in life expectancy are definitely related to income inequality. But the strength of that correlation varies depending on region.