In both the Deep and Upper

In both the Deep and Upper South regions, Blacks in counties with the lowest 1860 slave concentration actually experienced faster mean decline in heat disease mortality than Whites in those same counties (Fig. 2). However, as 1860 slave concentration increased, the rate of decline slows substantially for Blacks, but for Whites is either flat (Deep South) or accelerated (Upper South). Adjusting for region and accounting for spatial autocorrelation with spatial lag models, the relationships between slave concentration and declines in 5z disease mortality persists for Blacks but not Whites (Table 3). For Blacks, the confounder adjusted association (β -0.17, SE 0.028) is consistent with conventional regression, although the confounder and intermediate adjusted association is not attenuated as much in spatial as compared to aspatial models (β -0.13, SE 0.033). In contrast, for Whites there is no significant association between 1860 slave concentration and contemporary heart disease decline after accounting for spatial dependencies in the data. It is important to note that the interpretation of spatial lag econometric coefficients is somewhat distinct from conventional regression. Because these models include a spatially weighted average value of the dependent variable, heart disease decline, as a predictor variable, they are commonly interpreted as evidence of contagion or spread of health or health behaviors from one county to its neighbors (Voss, Long, Hammer, & Friedman, 2006). The degree to which a given county’s heart disease decline is predicted by neighboring counties heart disease decline is captured in the rho spatial lag coefficient reported in the last row of Table 3.
Discussion In the last five decades, heart disease mortality has declined dramatically across the United States, but the rate of decline for both Whites and Blacks has been slower in the South compared to other regions of the country (Casper et al., 2016; Vaughan et al., 2015). However, the South is not a monolithic region. The South has notable variation in heart disease mortality decline, including distinct patterns by race and place. The magnitude of reduction in heart disease mortality—the pace of public health progress—in counties at the end of the 20th century was associated with the concentration of slavery in 1860 for Blacks, but not Whites. Between 1968 and 2014, Blacks in counties with the highest 1860 concentration of slavery experienced slower rates of mortality declines compared to Blacks in counties with a history of lower slave concentration. Nearly half of this association is explained by inter-county 20th century differences in educational and economic racial inequalities, and the cumulative use of lynchings to enforce Black subordination.
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Acknowledgements