Longevity in rich countries

By THE DATA TEAM

POPULATION forecasting is not simple. Demographers use mortality data—information about when people die and why—to estimate the likely life expectancy of people still alive. The UN, the World Health Organisation (WHO) and others produce periodic forecasts that are fairly similar. Wealthy countries such as Japan, Switzerland and Australia have the highest life expectancies, though the estimates vary slightly depending on the methodology used. But a new study of 35 rich countries by researchers at Imperial College London and the WHO, and published in the Lancet, a medical journal, uses a combination of 21 statistical models, instead of just one. The results, say the authors, are more reliable. They are also surprising.

By 2030, they think, South Korea will have seen the biggest gains in life expectancy for both men and women. A girl born there in 2030 is likely to live past her 90th birthday, seven years longer than one born in 2010. South Korean men are expected to live to just over 84, leapfrogging 18 other countries to the top of the ranking.