My father’s life expectancy at birth was 48 years. He survived to be 83, and he was by several years younger at his death than his brothers and sister at their deaths. He and they lived through what has been called “the demographic transition,” from low life expectancies to high.
A recent paper in the Lancet charts the worldwide evolution of life expectancy between 1970 and 2010. Life expectancy has fallen in only 4 of the 187 countries with populations of 50,000 or more, the four being Zimbabwe, Lesotho, Ukraine, and Belarus. In the first two, AIDS was the cause; in the second two, alcohol.
Worldwide life expectancy between 1970 and 2010 rose at a rate of 3-4 years per decade, except for the 1990s, when the rate of improvement was considerably lower. In Asia and Latin America, the average age at death rose by 1 year every 2 years, a startling rate of improvement. But the greatest improvement in recent years has been in sub-Saharan Africa: life expectancy in Angola, Ethiopia, Niger, and Rwanda has increased by 10–15 years since 1990.
According to the authors, two medical interventions account for this: first the availability of anti-retroviral drugs to treat AIDS, and second the availability of both insecticide-treated mosquito nets and artemisin-combination treatment regimes for malaria.