California Center for Population Research

A considerable amount of research indicates that relative income is related to health, or more specifically, that greater disparities in income are related to poorer health. Referred to as the relative income hypothesis, the causal mechanisms, social implications and general nature of this relationship continue to stimulate interesting and important research across several disciplines. One dimension of the association between income inequality and health that has yet to be explored or considered fully is the geographical. In an attempt to elucidate and evaluate how geography is implicated with the relative income hypothesis, the role and significance of geographic spillovers, regional effects and diffusion are theorized and explored. This research uses a geographic framework, spatial analytic techniques, and current and imputed data to revisit and re-examine the linkage between relative income and health at the global scale. Results indicate that the association between income inequality and health is somewhat tempered when examined within an explicitly spatial framework, and that regional and geographic effects need to be considered and treated carefully in cross-sectional, international studies of health.