Analyzing potential shifts in life expectancy: The role of baseline mortality in addition to relative changes in death rates

To further explore a significant stagnation in life expectancy in the United States, Abrams et al. proposed a counterfactual approach in which the death rates observed in 2000 to 2009 are extrapolated into 2010 to 2019 (1). Their results show that sustained improvements in mortality at older ages, rather than at working ages, may have contributed more to the increase in life expectancy in the United States. Polizzi and Dowd suggest another counterfactual scenario: What would be the contribution of ages 25 to 64 versus 65+ to the life expectancy increase in the United States if relative changes in death rates were similar to those observed in other high-income countries in 2010 to 2019? (2) Conversely, their analysis highlights the vital role of midlife mortality to the changes in life expectancy...