One of the saddest developments in recent years is the decline in life expectancy in several of the world’s wealthier economies. This has been apparent, at least for some years, in many western European countries as well as in the US. Even when life expectancy has turned upwards in subsequent years it looks like the rate of improvement is slowing.

To put this into context, a trend towards higher life expectancy was long apparent. For example, life expectancy at birth in the high-income countries has increased from about 40 years in 1800 to about 80 years today. A doubling of life expectancy is a huge achievement which, in turn, reflects many other improvements in popular prosperity.

It is also noteworthy that the average life expectancy worldwide is 72 years, according to the latest figures from the World Health Organization. That means life expectancy in developing countries has also increased hugely, even if a substantial gap with the West remains.

In relation to the richer countries, two phases of improving life expectancy can be distinguished. Until about 1970 the main driver was a reduction in infant and child mortality as measures to combat infectious diseases improved. From the 1970s onwards a reduction in death rates for the elderly was the main driver of improvements.

Against this backdrop of improvement it is tragic that life expectancy has started to dip or at least improve more slowly. For example, life expectancy dipped in many European countries and in the US in 2015.

However, before drawing any sweeping conclusions it is necessary to sound a note of caution. For example, bad winters can hit life expectancy in the short term without changing the long-term trend. 

In the US, the opioid crisis, with an average of over 130 people a day dying from overdoses of opioid-related drugs, has played an important role. That is, of course, a tragedy for those involved but it does not necessarily represent a downward shift for the bulk of the population.

“Demographic trends tend to be outcomes rather than causes of broader social shifts”

It is also possible that life expectancy could take a sudden upward turn. Organisations such as the Sens Research Foundation makes a plausible case that, with the application of advanced technology, it should be possible to live to be 1,000.

Whatever turns out to be the trajectory of life expectancy, it should be recognised that improvements are driven by prosperity and technological advance. Demographic trends tend to be outcomes rather than causes of broader social shifts.

If stagnant longevity becomes a trend it will probably be the result of economic atrophy and sluggish technological innovation in the West.

Daniel Ben-Ami, Deputy Editor