A Decomposition of Black-White Differences in the Rate of Age-Related Mortality Increase

The increase in mortality rates with advancing age is thought to reflect functional decline and processes associated with physiological aging. When viewed on a logarithmic scale, mortality rates tend to increase at a constant rate in the adult age range. This “slope”, the Rate of Mortality Increase with age is commonly used as a measure of actuarial aging in biodemographic research. The goal of this paper is to examine the black-white difference in this slope – a lower rate of mortality increase among blacks. The analysis uses a unique application of classical decomposition methods to partition the black-white RMI disparity into two components, each reflecting a dimension of cause-specific mortality disparities between blacks and whites. The first component reflects the extent to which the rate of increase among blacks is lower for individual causes of death. The second reflects the extent to which the cause of death distribution among blacks is tilted towards causes of death that increase relatively slowly with age. These results are also related to the well-known black white mortality crossover – the tendency for mortality among whites to exceed that of blacks at the oldest ages.