[Abstract]  This article is concerned with sensitivity analysis of life disparity with respect to changes in mortality rates. A relationship is derived that describes the effect on life disparity caused by a perturbation of the force of mortality. Recently Zhang and Vaupel introduced a "threshold age", before which averting deaths reduces disparity, while averting deaths after that age increases disparity. I provide a refinement to this result by characterizing the ages at which averting deaths has an extremal impact on life disparity. The results are illustrated using data for the female populations of Denmark in 1835, and for the United States in 2005.

文章出处：Demographic Research 23: 63-72