The trend in Sweden holds for the rest of the world. In the early 1870s Italy’s life expectancy was under 30 years and the odds of death before age 5 nearly 45%. The estimated Gini index for age at death was 0.56. Today (2009) Italy’s life expectancy at birth is about 82 years, and the Gini index for the distribution of national lifespans is as low as Sweden’s.

And the U.S.? Life expectancy rose from about 61 years in 1933 to about 79 in 2010. Over those same decades the Gini index for lifespan inequality was cut in half—from 0.22 to 0.11. Despite the ethnic, income and other differences that characterize our society, Americans of all backgrounds have never enjoyed such equality in length of life as we know today.

Detailed, reliable, long-term mortality for most of the world is unavailable. However, the broad pattern for every national population is essentially the same: the higher the life expectancy at birth, the lower the inequality in age at death.