Our World in Data — demographics

About Our World in Data

Our World in Data’s mission is “to publish research and data to make progress against the world’s largest problems”. It makes data and knowledge accessible and understandable to empower those working to build a better world. Read more about Our World in Data’s mission on the problems and progress page.

Available topics and data

The site provides data across a broad range of topics, grouped under sections: 

• Population and Demographic Change
• Health
• Energy and Environment
• Food and Agriculture
• Poverty and Economic Development
• Education and Knowledge
• Innovation and Technological Change
• Living Conditions, Community and Wellbeing
• Human Rights and Democracy
• Violence and War

Each group has a link to topics, which include key insights, information, interactive charts and data sets, links to articles and research among others. For example the Population and Demographic Change group includes the following topics:

• Population Growth
• Age Structure
• Gender Ratio
• Life Expectancy
• Child and Infant Mortality
• Fertility Rate
• Urbanisation
• Migration

Population and demographic trends

The site provides a truly vast amount of information, so much so that you may think — what can I do with all this information? To break it down a bit, the site can be seen as a source of raw data sets with which visitors can conduct their own focused analysis on their topic of interest as well as a source of some very interesting key insights and pre-prepared analyses. In this article we’ll look at a couple of examples of both. We’ll look at three main topics; population growth, life expectancy and urbanisation.

Global population growth and rate of change

Population growth on our planet changed gear around 1800, when the estimated population was around one billion people. It now stands at over 8 billion, approximately a 700% increase. This huge increase was due to a number of factors including industrialisation and improvements in medical knowledge and public health, along with more regular food supply, a dramatic reduction in the death rate and no corresponding decline in the birth rate.

However, population growth is no longer exponential. Growth rates peaked in the 1960s and have been declining since. The chart below illustrates this, with the purple line showing a sharp decline, after peaking in the 1960s. In fact, the UN predicts that the global population will peak by the end of this century at around 10.4 billion people.

Global life expectancy — 1900 to 2021

One significant contributing factor to population growth is life expectancy. It’s hard to believe but around 1900, the average life expectancy of a newborn was 32 years, with infant mortality rates being much higher than they are today. By 2021 life expectancy had more than doubled to 71 years. This resource delves into the where, when, how, and why has this dramatic change in life expectancy occurred.

Some additional key insights in this topic area include:

• There are vast differences in life expectancy around the world
  • For example, in 2021, life expectancy in Nigeria and other parts of Africa was 30 years lower than in Japan.
• In 1950 the variations across and even within the continents of the world were enormous
  • For example in the United States it was 68.2 years, while in India it was 41.7 and in Mali only 28.2 years.

Urbanisation across the world today

On the scale of human history, urbanisation is a relatively new phenomenon. In the early 1800s the majority (around 90%) of the global population lived in rural areas. As can be seen in the chart below, the percentage of populations living in urban areas began to increase steeply from around 1850, albeit at quite different rates across different countries and regions. Currently more than half of the world’s population live in urban areas and increasingly in high-density cities. A sad, related fact is that almost 1-in-4 of those urban inhabitants live in slum household conditions.

Source:  HYDE (2023) – Learn more about this data OurWorldInData.org/urbanization | CC BY - Long-run history of urbanization

Data Insights section

This section of the site provides some pre-curated bite-sized insights across a very broad range of topics. Below we’ve listed a selection of interesting topics: 

• COVID-19 was the third largest cause of death in 2021
• Life expectancy is lower in the United States than in other high-income countries
• More countries have legalised same-sex marriage, but others have explicitly banned it
• Indoor air pollution causes over three million premature deaths every year
• Solar panel prices have fallen by around 20% every time global capacity doubled
• The price of lighting has dropped over 99.9% since 1700
• Which countries have fertility rates above or below the “replacement level”?

More about Our World in Data

For more information on Our World in Data’s mission or to explore the vast range of data available visit https://ourworldindata.org/, choose a topic of interest and dive in. Curated Daily Data Insights are also available and regularly updated.