The geography of American longevity: structural determinants of a 20-year life expectancy divide and a federal policy blueprint

Life expectancy in the United States exhibits striking geographic heterogeneity, with differences exceeding 20 years between counties despite shared national institutions and comparable aggregate healthcare expenditure. This study presents a comprehensive, ecological analysis of county-level variation in life expectancy, integrating socioeconomic status, education, healthcare access, behavioral risk factors, environmental exposures, demographic composition, and state policy environments. Drawing on publicly available datasets from the Centers for Disease Control and Prevention (CDC), U.S. Census Bureau, Bureau of Economic Analysis (BEA), Environmental Protection Agency (EPA), and related sources, we conceptualize life expectancy as an outcome associated with interacting structural determinants rather than the additive result of isolated population-level risk behaviors. We argue that commonly cited explanations—such as race, climate, or healthcare spending alone—are insufficient and frequently misinterpreted when examined outside a multivariate framework. Using hierarchical regression models with spatial robustness checks, this study demonstrates that socioeconomic conditions, particularly income, educational attainment, and labor-market stability, exhibit the strongest associations with spatial variation in life expectancy. At the same time, behavioral risks and environmental exposures appear to function as intermediate factors linking structural conditions to mortality outcomes. Race and ethnicity operate primarily as markers for cumulative structural disadvantage, although residual associations related to unmeasured dimensions of discrimination and segregation persist. Policy decisions at the state level, especially those affecting healthcare access, labor protections, and environmental regulation, exhibit long-term associations with population survival outcomes. Together, these findings challenge reductionist narratives that attribute geographic disparities in longevity to individual choice or immutable demographic factors, underscoring the central role of place-based structural conditions. The results have implications for health policy, social investment, and the evaluation of interventions to reduce inequities in population health.