Mortality Improvement

Mortality improvement at younger ages compresses deaths into a narrower age interval and increases lifespan equality. The effect of reducing mortality at a given age depends on deaths’ importance for life expectancy, survival to that age, and equality among survivors to that age. The study expresses changes in Drewnowski’s index as weighted averages of age-specific mortality improvements. Mortality improvement at older ages spreads deaths across a wider age interval and increases inequality by extending some already long lives. The threshold age can help decompose mortality change by age and clarify how age-specific hazards shape ages at death.