Life Expectancy

Life expectancy is the key metric for assessing population health. Broader than the narrow metric of the infant and child mortality, which focus solely at mortality at a young age, life expectancy captures the mortality along the entire life course. It tells us the average age of death in a population.

Estimates suggest that in a pre-modern, poor world, life expectancy was around 40 years in all regions of the world.

Life expectancy has increased rapidly since the Age of Enlightenment. In the early 19th century, life expectancy started to increase in the early industrialized countries while it stayed low in the rest of the world. This led to a very high inequality in how health was distributed across the world. Good health in the rich countries and persistently bad health in those countries that remained poor. Over the last decades this global inequality decreased. No country in the world has a lower life expectancy than the countries with the highest life expectancy in 1800. Many countries that not long ago were suffering from bad health are catching up rapidly.

Since 1900 the global average life expectancy has more than doubled and is now above 70 years. The inequality of life expectancy is still very large across and within countries. in 2019 the country with the lowest life expectancy is the Central African Republic with 53 years, in Japan life expectancy is 40 years longer.

## Differences in life expectancy across the world

The world map shows the latest data published by the United Nations for life expectancy.

Life expectancy is a measure of premature death and it shows large differences in health across the world.

The population of many of the richest countries in the world have life expectancies of over 90 years. In 2021 the life expectancy in Spain, Switzerland, Italy, and Australia was over 83 years. In Japan it was the highest with close to 95 years.

In the countries with the worst health life expectancy is between 60 and 70 years. The population of the Central African Republic has the lowest life expectancy in 2021 with 63 years.

Use the slider below the map to see the change over time or click on any country to see the changing of life expectancy around the world.

## Twice as long – life expectancy around the world

The three maps show the global history of life expectancy over the last two centuries.

Demographic research suggests that at the beginning of the 19th century no country in the world had a life expectancy longer than 50 years. Every country is shown in red. Almost everyone in the world lived in extreme poverty, we had very little medical knowledge, and in all countries our ancestors had to prepare for an early death.

Over the next 150 years *some* parts of the world achieved substantial health improvements. A global divide opened. In 1940 the life expectancy for newborns was already over 60 years in Europe, North America, Oceania, Japan and parts of South America. But elsewhere a newborn could only expect to live around 30 years. The global inequality in health was enormous in 1940: People in Norway had a life expectancy of 82 years, whilst in Mali this was 36 years. Africa as a whole had an average life expectancy of only 36 years, while people in other world regions could expect to live more than twice as long.

The decline of child mortality was important for the increase of life expectancy, but as we explain in our entry on life expectancy increasing life expectancy was certainly not only about falling child mortality – life expectancy increased at all ages.

Such improvements in life expectancy — despite being exclusive to particular countries — was a landmark sign of progress. It was the first time in human history that we achieved sustained improvements in health for entire populations.3 After millennia of stagnation in terrible health conditions the seal was finally broken.

Now, let’s look at the change since 1940. Many of us have not updated our world view. We still tend to think of the world as divided as it was in 1950. But in health — and many other aspects — the world has made rapid progress. Today most people in the world can expect to live as long as those in the very richest countries in 1950. The United Nations estimate a global average life expectancy of 82.6 years for 2021 – the global average today is higher than in any country back in 1950. According to the UN estimates the country with the best health in 1940 was Norway with a life expectancy of 82.3 years.

The three maps summarize the global history of life expectancy over the last two centuries: Back in 1800 a newborn baby could only expect a short life, no matter where in the world it was born. In 1950 newborns had the chance of a longer life if they were lucky enough to be born in the right place. In recent decades all regions of the world made very substantial progress, and it were those regions that were worst-off in 1950 that achieved the biggest progress since then. The divided world of 1950 has been narrowing.

Globally the life expectancy increased from less than 40 years to over 82 years; after two centuries of progress we can expect to live much more than twice as long as our ancestors. And this progress was not achieved in a few places. In every world region people today can expect to live more than twice as long.

The global inequalities in health that we see today also show that we can do much better. The almost unbelievable progress the entire world has achieved over the last two centuries should be encouragement enough for us to realize what is possible.

## Life expectancy has improved globally

This visualization shows the dramatic increase in life expectancy over the last few centuries as a line chart. For the UK – the country for which we have the longest time-series – we see that before the 19th century there was no trend for life expectancy: life expectancy fluctuated between 40 and 50 years.

Over the last 200 years people in all countries in the world achieved impressive progress in health that lead to increases in life expectancy. In the UK, life expectancy doubled and is now higher than 90 years. In Japan health started to improve later, but the country caught up quickly with the UK and surpassed it in the late 1960s. In South Korea health started to improve later still and the country achieved even faster progress than the UK and Japan; by now life expectancy in South Korea has surpassed life expectancy in the UK.

The chart also shows how low life expectancy was in some countries in the past: A century ago life expectancy in India and South Korea was as low as 23 years. A century later, life expectancy in India has almost tripled and in South Korea it has almost quadrupled.

You can switch to the map view to compare life expectancy across countries. This view shows that there are still huge differences between countries: people in Sub-Saharan countries have a life expectancy of less than 60 years, while in Japan it exceeds 90.

## Rising life expectancy around the world

In the pre-modern, poor world life expectancy was around 40 years in all regions of the world. The estimates by historian James Riley shown here suggest that there was some variation, between different world regions, but in all world regions life expectancy was well below 50 years.

The historical estimates are associated with a considerable uncertainty – it is worth reading the work by Riley to understand the limitations and strengths of the estimates.6 But of course these uncertainties are much smaller than the very large increase in life expectancy since then.

Infectious diseases raged in all parts of the world and as we show in our entry on child mortality almost half of all children died before they reached adulthood. And those that survived often died soon after. Without public health measures and without effective medicines diseases were killing most people at a very young age.

This was the reality for humanity until very recently. Life expectancy in each region of the world stayed fairly stable for most of history until humanity started to make progress against poor health just a few generations ago. Epidemiologists refer to this period in which life expectancy began to increase substantially as the “health transition”.

This chart shows that the health transition began at different times in different world regions; Oceania began to see increases in life expectancy around 1870, while Africa didn’t begin to see increases until around 1910.

Since then life expectancy doubled in all world regions.

* In Oceania life expectancy increased from 45 years before the health transition to 89 years in 2021.
* In Europe from 44 to 89 years.
* In the Americas from 45 to 87 years.
* In Asia from 37.5 to 83.6.
* And in Africa from 36 years to 73 years.

Globally the life expectancy increased from an average of 39 to 83 years in 2021.

## Life expectancy increased in all countries of the world

There is a lot of information in the following – rather unusual – chart. On the x-axis you find the cumulative share of the world population. And all the countries of the world are ordered along the x-axis ascending by the life expectancy of the population. On the y-axis you see the life expectancy of each country.

For 1800 (red line) you see that the countries on the left – India and also South Korea – have a life expectancy around 35. On the very right you see that in 1800 no country had a life expectancy above 50 (Belgium had the highest life expectancy with just 50 years).

In 1940 the life expectancy of all countries was higher than in 1800 and the richer countries in Europe and North America had life expectancies over 70 years – over the course of modernization and industrialization the health of the population improved dramatically. But half of the world’s population – look at India and China – made only little progress. Therefore the world in 1940 was highly unequal in living standards – clearly devided between developed countries and developing countries.

This division is ending: Look at the change between 1940 and 2014! Now it is the former developing countries – the countries that were worst off in 1950 – that achieved the fastest progress. While some countries (mostly in Africa) are lacking behind. But many of the former developing countries have caught up and we achieved a dramatic reduction of global health inequality.

The world developed from equally poor health in 1800 to great inequality in 1940 and back to more equality today – but equality on a much higher level.

***How to read the following graph:** On the x-axis you find the cumulative share of the world population. The countries are ordered along the x-axis ascending by the life expectancy of the population.*

## It is not only about child mortality – life expectancy by age

It’s often argued that life expectancy across the world has *only* increased because child mortality has fallen. If this were true, this would mean that we’ve become much better at preventing young children from dying, but have achieved nothing to improve the survival of older children, adolescents and adults. Once past childhood, people would be expected to enjoy the same length of life as they did centuries ago.

This, as we will see in the data below, is untrue. Life expectancy has increased at all ages. The average person can expect to live a longer life than in the past, irrespective of what age they are.

### Life expectancy by age in England and Wales

The visualization shows the life expectancy in England and Wales over the last three centuries.

The red line shows the life expectancy for a newborn. Until the mid-19th century a newborn could expect to live around 50 years. At times, even less.

The rainbow-colored lines show how long a person could expect to live once they had reached that given, older, age. The light green line, for example, represents the life expectancy for children who had reached age 20.

The most striking development we see is the dramatic increase in life expectancy since the mid-19th century. Life expectancy at birth doubled from around 40 years to more than 81 years.8 This achievement was not limited to England and Wales; since the late 19th century life expectancy doubled across all regions of the world.

While England and Wales are not the only region that achieved this improvement, the last 150 years are the only *time* that humanity achieved anything like this. The evidence that we have for population health before modern times suggest that around a quarter of all infants died in the first year of life and almost half died before they reached the end of puberty (see here) and there was no trend for life expectancy before the modern improvement in health: In the centuries preceding this chart, life expectancy fluctuated between 40 and 50 years with no marked increase ever.

**Life expectancy increased at all ages**

A common criticism of the statement that life expectancy doubled is that this “only happened because child mortality declined”. I think that, even if this were true, it would be one of humanity’s greatest achievements, but in fact, this assertion is also just plain wrong. Mortality rates declined, and consequently life expectancy increased, *for all age groups*.

The data shown in this chart makes this clear.

Let’s see how life expectancy has improved without taking the massive improvements in child mortality into account. Child mortality is defined as the share of children who die before reaching their 5th birthday. We therefore have to look at the life expectancy of a five-year-old to see how mortality changed without taking child mortality into account. This is shown by the yellow line. In 1841 a five-year-old could expect to live 65 years. Today a five-year-old can expect to live 92 years. An increase of 27 years.

The same is true for any higher age cut-off. A 60-year-old, for example, could once expect to live up to the age of 71. Today, a 50-year-old can expect to live to the age of 93. A gain of 13 years.

This is true for countries around the world. Here is the data for the life expectancy of 10-year-olds around the world.

A second striking feature of this visualization is the big decline of life expectancy in 1918. It was caused by a very large global influenza epidemic, the Spanish flu pandemic. I have studied the impact of this pandemic and especially it’s differential impact for different age-groups – the life expectancy of older people barely changed as the chart shows – in a text on the this pandemic here.

Yes, the decline of child mortality matters a lot for life expectancy. But as we’ve seen, the gains go much further than this. As we have seen here it was not only children that benefited from this progress, but people at all ages.

### A different view on mortality by age – survival curves

‘Population survival curves’ show the share of people who are expected to survive up to a certain age. The chart here plots the survival curves for individuals in England and Wales from 1843 up to 2013.

As we can see, less than half of the people born in the mid-19th century made it past their 50th birthday. In contrast, 97% of the people born in England and Wales today can expect to live longer than 60 years.

Life expectancy estimates only describe averages, these curves therefore provide an important complementary view and help us understand how the inequality of life lengths has changed over time. In the 19th century the inequality was very large, many died at a very young age and a considerable number of people died between the age of 5 and 70. Today the inequality is much lower, the huge majority survives the first 70 or 80 years of their life and the span at which most people die is much more compressed than it was 160 years ago.

### A comparative perspective – life expectancy at the age of 10

The following visualization shows the estimates and UN-projections of the remaining expected life years for 10-year-olds. The rise – best visible on the Map-view – shows that the increasing life expectancy is not only due to declining child mortality, but that mortality rates at higher ages also declined globally.