Trading Off Longer Life for Worsening Health

Abstract
This article demonstrates and explains why future declines in mortality will have a diminishing effect on the metric of life expectancy but a large impact on the size of future elderly cohorts. Additionally, the article addresses a hypothesis in which it is argued that morbidity and disability will decline and become compressed into a shorter duration of time before death. Although studies have demonstrated that declining mortality can lead to worsening health, what is missing from the literature is a formal mechanistic hypothesis that describes why this phenomenon takes place. Two primary mechanisms are identified. One is based on arguments in which medical technology is identified to improve the survival of those with disabling conditions; the other is that declining mortality from fatal diseases leads to a shift in the distribution of causes of disability from fatal to nonfatal diseases of aging. Procedures for testing this hypothesis are discussed.