Population ageing is occurring because of declining
fertility rates, lower infant mortality and increasing
survival at older ages. Total fertility dropped by half
from five children per woman in 1950-1955 to 2.5 children
in 2010-2015, and it is expected to continue to decline.
Life expectancy at birth has risen substantially across
the world; it is not just a developed world phenomenon.
In 2010-2015, life expectancy is 78 years in developed
countries and 68 years in developing regions. By
2045-2050, newborns can expect to live to 83 years in
developed regions and 74 years in developing regions.
While overall the world is ageing, there are differences
in the speed of population ageing. It is happening fastest
in the developing world (Figure 2). Today, almost two in
three people aged 60 or over live in developing countries,
and by 2050, nearly four in five will live in the
developing world...