Does regional variation affect ecological mortality research? An examination of mortality, income inequality and health infrastructure in the Mississippi Delta

Mortality research has often focused on individual-level, socioeconomic, and demographic factors indicating health outcomes. Consistent with a recent trend in the public health field, this research examines mortality at the aggregate, contextual level. Based on Wilkinson’s relative income hypothesis, specifically being manifest through an underinvestment in social goods including health infrastructure, the focus of this study is a regional examination in the effects of income inequality on mortality at the county level. Health infrastructure is included as a mediating variable in the relationship between income inequality and mortality, relating back to Wilkinson’s work. Unlike previous research, regional differences in this relationship are examined to identify variation at the county level in health outcomes. The Mississippi Delta is an adequate test bed to examine the relationship between these variables based on its socioeconomic, demographic, and high inequality characteristics. It is hypothesized that Delta-designated counties within the three-state Delta region distinguish a significant positive relationship between income inequality and mortality, that this relationship is stronger than in non-Delta classified counties, and that health infrastructure significantly mediates the relationship between income inequality and mortality.