Rising life expectancies, in the United States and around the world, are one of the most
extraordinary achievements of the 20th century. Table 1 shows that a U.S. man born in 1900 had
a life expectancy of 51.5 years, and less than a fifty percent chance of reaching age 65. A century
later, a newborn male was projected to have a life expectancy of 80 years, and an 86 percent
chance of celebrating his 65th birthday. For a woman, the gains were nearly as large. In 1900, a
newborn girl's life expectancy was 58.3 years and she had a 57 percent chance of reaching her
65th birthday. In 2000, life expectancy at birth was 84.2 years and the probability of reaching
the age of 65 was projected to exceed 90 percent. Between 1900 and 2000, the expected share of
a newborn boy's life that would be accounted for by years lived beyond the age of 65 rose from
12.2 percent to 22.0 percent. For newborn girls, the change was from 17.9 to 24.7 percent. The
changes at even older ages have been more dramatic. In the 2000 birth cohort, males and
females could expect to live 4.3 and 6.1 percent of their lives, respectively, beyond age 85. The
corresponding values for the 1900 birth cohort were 1.1 and 2.9 percent. Karen Eggleston and
Victor Fuchs (2012) observe that prospectively, most of the extension of life length is likely to
be due to reductions in mortality rates at older ages, which implies continued growth in the
population share accounted for by the "oldest old.