Death rates at specific life stages mold the sex gap in life expectancy

Abstract

Why do women live longer than men? Here, we mine rich lodes of demographic data to reveal that lower female mortality at particular ages is decisive-and that the important ages changed around 1950. Earlier, excess mortality among baby boys was crucial; afterward, the gap largely resulted from elevated mortality among men 60+. Young males bear modest responsibility for the sex gap in life expectancy: Depending on the country and time, their mortality accounts for less than a quarter and often less than a 10th of the gap. Understanding the impact on life expectancy of differences between male and female risks of death by age, over time, and across populations yields insights for research on how the lives of men and women differ.

Keywords: decomposition; life expectancy; sex gap.

Fig. 1.

(A) Ratio of male-to-female probability of death in the most recent available year for Russia (2014), Japan (2019), United States (2018), and Sweden (2019). (B) Ratio of male-to-female probability of death in Sweden in different years (smoothed). (C) Difference of male–female probability of death (on log scale) in the most recent year. (D) Relative age-specific contribution over time to the gender gap in life expectancy in Russia, Japan, United States, and Sweden. For a few years, the lowest value is less than zero and the highest value correspondingly greater than 1. In these years, female mortality in one of the age classes exceeded male mortality, reducing the life expectancy gap. Data are from the Human Mortality Database (8).

Fig. 2.

(A) Sex difference in infant mortality rate (IMR) over time for Sweden, United States, Japan, and Russia. (B) Ratio for Sweden of male-to-female infant mortality rate (IMR) by level of female infant mortality rate. (C) Sex difference in mortality at ages 15 to 40 over time. (D) Absolute age-specific contributions to sex gap in life expectancy over time in Russia, Japan, United States, and Sweden. (E) Absolute contributions by single year of age to sex gap in life expectancy in Sweden, with diagonal lines marking the cohorts born in 1900 and 1930. Data are from the Human Mortality Database (8).