The American Academy of Actuaries has released a new public policy paper and issue brief cautioning that clarification may be needed regarding estimated life expectancy showing significant decreases in light of the COVID-19 pandemic.
“Reports of considerable decreases in life expectancy driven by COVID-19 may certainly garner attention, but they can potentially be misleading when based on a technical measure that assumes heightened pandemic mortality will persist indefinitely,” said Academy Senior Pension Fellow Linda K. Stone. “Service to the public is core to the American Academy of Actuaries’ mission, and we would be remiss not to share the actuarial profession’s expertise to help the public interpret such reports.”
The Academy’s new Essential Elements paper,Clarifying Misunderstanding of Life Expectancy and COVID-19, which is based on a December 2021 issue brief developed by the Academy’s Pension Committee, Interpreting Pandemic-Related Decreases in Life Expectancy, cites the potential of confusion arising from recent Centers for Disease Control and Prevention (CDC) estimates of significant life expectancy decreases primarily due to COVID-19. The CDC used a measurement known as “period life expectancy” to estimate life expectancy changes in 2020, publishing in July 2021 a preliminary estimate of a 1.5-year year-over-year decrease, and in December 2021 a final estimate of a 1.8-year decrease. However, the CDC’s methodology and the estimated decreases assume that the heightened mortality of the COVID-19 pandemic during the 2020 year will persist indefinitely—an unlikely scenario.
Period life expectancy measures demonstrate fluctuations that reflect events that influenced mortality in this particular period.14 For example, the Spanish flu pandemic of 1918 resulted in a dramatic decrease in period life expectancy, which was more than offset by an increase in period life expectancy the next year. A male baby born in 1917 had a period life expectancy of 52.2 years, while a male baby born in 1918 had a period life expectancy of only 45.3 years—a reduction of almost 7 years.15 The following year, a male newborn had a period life expectancy of 54.2, an increase of almost 9 years over the period life expectancy calculated in 1918 for a newborn male. These changes are much larger than those seen thus far with COVID-19, demonstrating the relative severity of that earlier pandemic relative to the current one.
It is instructive to review the impact of calculating life expectancies on a cohort basis, rather than a period basis, for these three cohorts of male newborns in the late 1910s. Using mortality rates published by the SSA for years after 1917, for a cohort of 1917 male newborns, the average life span was 59.4; for the 1918 cohort, average life span was 60.0; and for 1919, it was 61.5. Even these differences are heavily influenced by the fact that the 1917 and 1918 cohorts had to survive the high rates of death during 1918, while the 1919 cohort did not.
If both period and cohort life expectancy are measured as of 1920 for each of these groups (the 3-year-old children who were born in 1917, 2-year-old children who were born in 1918 and 1-year-old children who were born in 1919), differences are observed in these measures as they narrow substantially because the high rates of mortality during 1918 have no effect on those who survived to 1920. This is summarized in the table below.