# What is Our World In Data?

Our World in Data (OWID) is an online publication that shows how living conditions are changing. The aim is to give a global overview and to show changes over the very long run, so that we can see where we are coming from and where we are today.

Our World in Data communicates this empirical knowledge in two ways:

  1. through data visualizations – charts and maps.
  2. by presenting the academic research on global development that explains what drives the changes that we see and what the consequences of these changes are.

The publication is produced at the University of Oxford and currently created by a team of three: The economist Esteban Ortiz Ospina, the web developer Jaiden Mispy, and the founder of the publication Max Roser.

Our World in Data covers a wide range of topics across many academic disciplines: Trends in health, food provision, the growth and distribution of incomes, violence, rights, wars, culture, energy use, education, and environmental changes are empirically analysed and visualized in this web publication. For each topic the quality of the data is discussed and, by pointing the visitor to the sources, this website is also a database of databases. Covering all of these aspects in one resource makes it possible to understand how the observed long-run trends are interlinked.

Our World in Data aims to bridge the gap between the important research findings of experts in narrow academic fields and the public that is interested in this research, but is unable to find, access, and sometimes understand this research. Our publication reaches several hundred thousand readers every month and from feedback and exchange with readers we know that the audience is comprised of interested readers, journalists, academics, and policy makers. The demand for our work shows us that there are many of us that are interested in how the world is changing, but find it hard to get access to the relevant research.

Individual data entries deal with the different aspects of living standards, you find these entries in the menu structured into 16 categories that always stays at the top. Additionally we have a small Our World in Data blog.

Our World In Data is entirely made available as a public good:

  • The entire publication is freely available,
  • all data published on the website is available for download,
  • our visualizations of data published on Our World in Data are made available under a permissive Creative Commons (CC-BY-SA) license so that everyone can use them,
  • and all the tools to publish OWID and to create the visualizations are free to use by everyone (completely open source and available on GitHub here).

The presentation of text and data makes use of the capabilities of online publishing. Almost all publications on the web – including those in the best journals – are currently just emulating the possibilities and restrictions of publishing on paper. They are published online, yet they are static combinations of text and visuals which were essentially already at the disposal of Johannes Gutenberg when he invented the printing press in the 1440s. Our World in Data uses the possibilities of the web – links that show the interconnectedness of development, options are available to search and explore the publication, and the empirical evidence is presented in interactive visualizations that can be explored, saved, and for which the data can be directly downloaded. To further move from a static medium to a dynamic medium with computational responsiveness is one of the key aims of Our World in Data.

# The Content of Our World in Data

# The data entries

OWID entries give the reader an overview of how a particular social, economic or ecological aspect of the world has changed over the long run. These entries are arranged into the 16 categories that you find in the menu on the very top of the page.

The content structure of each entry is shown in the following figure:

Data Entry Structure

In the 1st section of every data entry – the section titled ‘I. Empirical View’ – we present the most important facts of the long-term development of the topic of that data entry. The presentation of these trends makes use of interactive data visualizations and presents the available empirical evidence about what we know about the historical development (up to now) about each of the many different aspects of global development. The data visualizations are a distinctive feature of OurWorldInData and are often used in journalistic and academic articles, on social media and in school and university teaching.

Here is an example for a data visualization in section I.: The world map shows how life expectancy has changed over time. Use the slider below the map to see the change over time. (If you click on Chart in the top right corner you can explore the change for each country in the world.)

Section 2 is titled ‘Determinants & Consequences‘. To illustrate and communicate the research findings in this section we also use data visualizations – while the summarized (and referenced) research will show the current evidence on what is behind the observed changes and what they mean for our living conditions. To give a concrete example, while the peer-reviewed research on the causal links between mother’s education and higher child survival is summarized, this same section is illustrated with the correlation of these two measures across countries.

Section 3 is a very important section: Too often empirical studies are not critical enough about the data that is used in their empirical research (and this is equally an issue for data visualizations which are shared online for example on social media sites). Section 3 – ‘Measurement, Data Quality & Definitions’ – defines the used measures and explains the limitations of the empirical data by reviewing the literature that scrutinizes the available empirical data on the particular topic.

Section 4 is pointing the visitor to the relevant original data sources and allows interested researchers to study the empirical evidence themselves.

# Presentations

To give overviews over bigger topics – violence, hunger, poverty, etc – we produce presentations that cut across many topics that are covered in dedicated entries.

These presentations can be accessed on the front page in the menu titled ‘The Visual History of …”.

# What we are working on and what will be added later

Our World in Data is always a work in progress. We will be working on this for many years.

We are a small team, have limited funding, and this is a huge project.

Entries that are already comprehensive and pretty complete are marked with a star in the menu. Other entries (those not marked with the star) are only sketches of more comprehensive entries that we plan to write later. Many entries that we will definitely add in the future are not yet online.

We have a list of all current and future data-entries that shows which topics we will cover in this publication. There will be 275 entries. Offline we are constantly collecting material for the future entries; this catalogue includes much more than ten thousand references to visualisations, data sources, and research papers.


Currently (in 2017) we are not adding more topics and instead focus on the content that is already in the publication. The priority for the next months is to revise and extend the following entries:

  • Extreme poverty
  • Literacy
  • Population growth
  • Child mortality
  • Happiness and life satisfaction
  • War
  • Democratisation
  • Technological Progress
  • Hunger & Undernourishment
  • Economic Growth over the Very Long Run
  • Income Inequality
  • Fertility
  • Financing of Education
  • Financing of Health
  • Government Revenue [and Composition of Tax Revenues]

The only completely new entries that we do want to add in the coming months are three entries on gender aspects of development. These three entries will focus on three different dimensions – economically, political, and empirical evidence on rights and violence.

In addition to this we are always improving the technical framework – the website, the database and the visualisation tool.

# The Team

The intention for this publication was always to be a collaborative work and from 2015 onwards several researchers contributed to the content and web developers expanded the technical framework of the publication:

# Current Our World In Data team

Since February 2016: Jaiden Mispy, a web developer with experience in the software industry, who is interested in using technology to improve academic work. In the past, Jaiden has helped build tools which assist researchers from various fields, particularly in genetics and quantum physics. Jaiden is developing the very heart of this web publication – our data storage and visualization tool owid-grapher. This tool is open source and free to use by everyone. Contact: [email protected]

Since February 2016: Dr. Esteban Ortiz Ospina who is an economist and a Research Associate at the Blavatnik School of Government, University of Oxford. He was Departmental Lecturer in Economics at the University of Oxford from September 2013 to January 2016. His main research interests are in applied microeconomics. He completed his DPhil in Economics at the University of Oxford focusing on theoretical models of selection under uncertainty, applying them to issues of access to higher education. His current research studies issues such as the implications of discrimination in university admissions. You find more about Esteban on his personal page at the Blavatnik School of Government. Contact: [email protected]

Our World In Data was founded and is run by Dr. Max Roser. I started working on this in 2011 and built this online publication over the course of several years until we received donations and support from foundation that allowed us to work together as a team. I am an economist working at the University of Oxford and my work is split in two closely related parts: partly I do research on poverty, health, and the distributions of incomes and partly I work on this online publication. The close link between these two parts is the focus on studying the long-term growth and the distribution of living standards. I want to understand how the world is changing and why.
My background is in economics, geoscience and philosophy and my research. At Oxford I am working at the Oxford Martin School. My personal website is MaxRoser.com. Contact: [email protected]

# Former members of the Our World In Data team

May 2015 to September 2015: Lindsay Lee, who has a background in Applied Statistics and continued to do a Master in Public Policy has been working to expand content – particularly on health and demographics – and make the content more consistent across the site. Her personal site is LindsayEvansLee.com. Lindsay continued her studies at the University of Oxford after her work at OWID.

June 2015 to October 2015: Mohamed Nagdy completed his MPhil in Economics in 2015 at the University of Oxford. He is an economist with particularly strong empirical skills and helped to expand the content on the growth and distribution of incomes, economic development, violence, and education. Mohamed worked as an economist in London after his work at OWID.

May 2015 to January 2016: Zdenek Hynek, a London-based web developer. He has very strong stills in the technologies that are used for visualising data on the web, including JavaScript, d3.js, php and SQL. His company is here geographics.cz. Zdenek joined a top information design agency after his work for OWID.

July 2015 to August 2015: Julia Murphy, who has a background in economics and engineering (Dartmouth College) was contributing to this project in the summer of 2015 and focused on expanding the section ‘Media & Communication’. Julia continued her studies after her internship at OWID.

# External contributors to Our World in Data

Professor Brian Nolan and Dr Stefan Thewissen from Oxford University are coauthors of the the entry on Incomes across the Distribution.

# Advisers

Our World in Data was developed in collaboration with Sir Tony Atkinson. He developed the idea for this publication together with Max and remained an adviser to the project until his death in 2017. Sir David Hendry  was the Principal Investigator in the initial phase of the project. We are very grateful for their support and advise through the years.

# Why are we working on Our World In Data?

# Because the daily news are not enough to know about the world

The media focuses on events, Our World in Data focuses on slow but long-lasting developments. News channels that focus on events are not able to show how our world is changing since many of the long trends that transformed our world do not get covered in the news and surely never make the headlines.

Here is an example: The number of people living in extreme poverty fell from close to 2 billion in 1990 to 0.7 billion in 2015 (see here). On no day in this 25 year period was the headline of any newspaper in the world “The number of people in extreme poverty fell by 137,000 since yesterday”. This is despite the fact that – on average – this would have been an accurate headline every single day during these 25 years.1

Because the media – as well as schools and universities – largely neglect reporting slow but transformative news the large public is extremely poorly educated about these developments. Even the decline of global extreme poverty – by any standard one of the most important developments in our lifetime – is only known by a small fraction of the population of the UK (10%), South Africa (14%), Norway (17%), Sweden (23%), and the US (5%).2

A second example: Global child mortality fell from 18.2% in 1960 to 4.3% in 2015; while 4.3% is still too high, this is a substantial achievement. But similarly on no day in the last 5 decades was there ever the headline ‘Global Child Mortality Fell by 0.00719% Since Yesterday’.

The focus of journalists on single events is understandable, the work of journalists is to write interesting stories and the history of progress is largely about the absence of exciting stories – fewer deaths, less poverty, less violence. The unbalanced account of the media and of some intellectuals however, is translated to a popular conception of the development of the world that is too negative.

We think this ignorance about global development matters. Constant doom saying and the failure to report the accomplishment of our efforts is nurturing cynicism. It is especially sad when those who care about the development of our world turn away as they see no information on global development that would give them hope.

The motivation for publishing OurWorldInData could not be explained better than in the words of Albert Schweitzer who realized several decades ago:

Now we can make a publication on real progress possible, with a reach and in a technological form that was unimaginable by Schweitzer.

We have to communicate how global living conditions are gradually changing and OurWorldInData aims to be a complementary source to the news that informs us all about the world.

Because I was disappointed and angry with a media and education that were not informing me and others about these and other fundamental trends that changes our world I started working on Our World in Data in 2011.


# Because statistics – not only single stories – are needed to get an idea of our world

Our culture – both in certain parts of academia and in the public discussion – is too focussed on single events and we overestimate our ability to arrive at a reliable picture of our world. By only focussing on single developments we cannot understand how the world is changing.

There is no way of knowing how living conditions change in your country or in the world as a whole without good statistical work.

The issue we are tackling with Our World In Data is that the barriers for the general public to get informed by the important quantitative social research carried out in academic institutions are frustratingly high. OurWorldInData changes this and makes research on social, economic and environmental trends accessible.

As argued before, we are mistaken if we believe that we can be informed how the world is changing by only following the news. News are important to know what happens in an instant, but they fail to convey what happens slowly but steadily over long stretches of time.

This is very unfortunate because it tilts the information about our world to negative aspects – things that go wrong.

The empirical view of our world over the long term shows how the Enlightenment continues to make our world a better place. It chronicles how human societies became less violent and increasingly more democratic. The empirical evidence shows how new ideas continue to improve living standards, allowing us to live a healthierricher and happier life. It is the story of declining poverty and better food provision in a world we care about.

Most of the long-run trends are positive and paint an optimistic view of our world that is unknown to many who only follow the daily news to inform themselves about the world. The research presented on OWID backs up the statement by Karl Popper.


The empirical view on our world shows how misplaced doom and defeatism often were and my aim is to encourage those who work to make our world a better place still. At the same time my hope is also to help to change the mind of those of you who do not think that we are creating a better world. By looking at the empirical data I want to explain why I am optimistic about how we are changing our world and why I think it is worthwhile to engage in the global long-term project of Enlightenment. Although most trends are clearly going in the right direction I also show where this is not the case. In a world of hysteria we cannot focus on what is important, but a fact-based view on our world should help us to focus on the topics that are most important.

# To pursue more of what works and to get engaged in a world that achieves progress

The annual question of the science portal Edge is “What do you consider the most interesting recent scientific news?” and Professor Steven Pinker answered that in his opinion it is the possibility to “quantify human progress”.
Pinker explains why he considers this to be the most important and interesting news: “Foremost, quantified progress is a feedback signal for adjusting what we have been doing. The gifts of progress we have enjoyed are the result of institutions and norms that have become entrenched in the last two centuries: reason, science, technology, education, expertise, democracy, regulated markets, and a moral commitment to human rights and human flourishing.”
The motivation of publishing Our World In Data is indeed to be more constructive about development. We have to know what works so that we pursue more of it. To me this is also about trust in our institutions and about believing in each other. It is too easy to be cynical about the world and cynicism is leading to misanthropy.

The absence of information on global development has an additional sorry consequence: The lack of feedback on our efforts as a society can make us lose trust in ourselves and at the extreme make us lose will to change the world for the better.
Here is how a reader of OurWorldInData put it in an email: “nobody is able to accomplish anything when ones mind is preoccupied with negative news, insecurity, and fear. Quite the contrary, to achieve something great we need to know that our efforts are worthwhile, yet understand that many aspects need our work so that we can further improve our world.”
It is disempowering if we wrongly think that we are going down the wrong way and contrariwise it can be empowering to know that we are doing something right.
It reinforces development also because it makes us ask questions. To see how agricultural yields have increased or how the child mortality rate is falling in all countries in the world makes you ask questions.

We need to present the research that lets us understand why living conditions change. What is driving progress to improve global health and education and how can we further reduce extreme poverty, violence, hunger? We need to bridge the gap between researchers and the public and clearly show that we have it in our hands to work towards a world where living conditions are improving for all of us. We can be more effective when the public – including policy makers, journalists, and academics – knows where and how we need to act to improve living conditions for every person around the world.

Our World in Data is about solutions as much as problems.

# To communicate what we know about global development, to choose better policies

The aim for the web publication Our World in Data is to bring together the best available quantitative research on the many different aspects of global development and to present the most reliable empirical data openly to the public.
We believe that communicating knowledge about global development matters for the quality of our democratic political system and ultimately for better decisions by policy makers and citizens. Democracy depends on informed citizens and the knowledge on global development and global challenges will help us to seek better policies.
Democracy crucially depends on informed consent and people view their world very different if they falsely believe that global living conditions are getting worse.  Fortunately empirical evidence is increasingly becoming the basis for political discussions and decisions and this project will provide a database for discussants to refer to. It is helpful for this form of political debate because while statistics are becoming the principal language of public argument, a comprehensive platform on global development accessible to the interested citizen does not exist.

OurWorldInData is motivated by the sense that statistics are the dominant language of public argument. The interactive visualizations – licensed under a permissive BY-SA-Creative Commons license – are directly usable for journalists (who can either copy the visualizations or directly embed them in their web publications). The experience with Our World In Data shows that many of us do pay attention to evidence and that there is a strong demand for the research on global development presented in this publication. The reason why research and data on global development does not play a larger part in the public debate and perception is the gap between academia and the wider public. For researchers, policy makers, and the public an open approach to empirical evidence is the best way to maximize the benefits of research.

There would be no greater misunderstanding than to interpret the content of Our World in Data as suggesting that we should pat our selves on the back and say we are happy with where we are. This is a publication about change and really about the necessity for constant change in order to move ahead. We want people to complain. The purpose of this research project is not to stop people from complaining; on the contrary our argument is that a reasoned critique — that involves considering what we have learned through the progress we achieved in modern history — is beneficial in bringing about change and helping to create a better world.

An honest account of the state of humanity is important to be able to further progress and human solidarity by criticizing the wrongs of today. In a sea of hysteria it is hard to hear the important warnings and to point out the issues that truly matter.

Visualising data is a form of knowledge compression and the experience has shown that investing in Our World In Data is therefore an effective way to communicate research through the media and influence policy and public understanding of our world.

# To know where to focus our efforts and to get more of us in development

Our World In Data always shows both, the change so far and the challenge ahead. In the Visual History of World Poverty we see the reduction of extreme poverty from 44% in 1981 to less than 10% in 2015. This reduction is an extraordinary achievement. But at the same this data visualisation and the accompanying entry on OurWorldInData  also show that almost 10% of the world population live in extreme poverty – clearly an outrageously high number of individuals that live in abysmal living conditions in our present world.
The medical doctor and director of the Global Burden of Disease study Chris Murray believes that “You could solve humanity’s most pressing problems once you recognize them […] that’s why I keep obsessing about marshaling the facts and putting them in a way for people who need to think about them”.3 OurWorldInData does both, it shows the successes so far and the pressing challenges ahead so that we know where we should focus our efforts.
We are convinced that portraying the difficult yet successful efforts of humanity will be a helpful way to look at history and our present condition. In this spirit our work is directed against cynicism and in favor of engagement in a developing world.

There is no reason that human history turned this way. It would be false to pretend that what has happened had to happen, after all the revolutions to living standards did not happen for millennia. And although I’m optimistic there is no reason that it continues this way. We have to keep working for a better world and the book will present what we can learn from the successful aspects of development so far.

We need to know in which aspects the world has seen progress and why and we also need to show where people live in destitute conditions and present clearly what the big challenges of today are. This helps us to prioritize where and on which aspects policy makers and all of us focus our efforts.

# To communicate a broad understanding of development – not just economic growth

The perception and discussion of development is focused on a single, narrow aspect of development: Economic growth.
The growth of incomes is important, yet it is a means to an end and certainly it is no guarantee that we achieve the ends of development that we care about (health, education, human freedom, sustainable relationship with nature and more). Our World In Data promotes a broad understanding of what development means. The aim is to broaden the debate and make measures of health and other aspects of development as ubiquitous and easy to access as data on economic output is today.
The Millennium Development Goals with a focus on health and even more the Sustainable Development Goals with the understanding that development is even broader were steps in the right direction. Our World In Data gives this perspective a permanent home.

As recommended by Stiglitz, Sen, and Fitoussi (2009), GDP per capita remains an important part of the empirical perspective on development, but the measure will not be used to capture aspects that it is not able to capture. For the wider range of aspects of development OurWorldInData will also follow the recommendation of the Stiglitz, Sen, and Fitoussi report and present a range of indicators (dashboard approach). The website is therefore structured into 16 categories and aims to communicate the empirical research on all of these aspects:

  1. Population Growth & Vital Statistics
  2. Health
  3. Food & Agriculture
  4. Resources & Energy
  5. Environmental Change
  6. Technology & Infrastructure
  7. Growth & Distribution of Prosperity
  8. Economic Development, Work & Standard of Living
  9. The Public Sector & Economic System
  10. Global Interconnections
  11. War & Peace
  12. Political Regime
  13. Violence & Rights
  14. Education & Knowledge
  15. Media & Communication
  16. Culture, Values & Society

# Because our cognition makes it likely that we become pessimistic

The important consequence of the media’s focus on events rather than slow trends is that global development does not get reported. Harm is done in an instant and disasters are happening at once: an earthquake, a plane crash, or the attack of a group of terrorists. In contrast, many of the best news for life on earth are shaped by trends that slowly and over the course of decades or centuries change our world.

The fact that the media fails to communicate a large part of global development would be less an issue if our own perception would provide us with an accurate representation of how the world is changing.
Unfortunately this is not the case. And even worse, the lack of information on global development is compounded by, rather than corrected by, our perception: We are bad intuitive statisticians. This – in a nutshell – is the research result of psychologists and behavioral economists, summarized in Daniel Kahneman’s Thinking, Fast and Slow.
Two of the important biases that make us such bad intuitive statisticians are:
–    The availability heuristic biases our perception towards the events that we see repeatedly and for which we can recall examples easily. This is aggravating the predicament of a media that mostly focuses on gloomy event news.
–    The negativity bias describes the fact that our perception responds more strongly to unpleasant news. From an evolutionary perspective it is clear that it is most important for an organism to survive that it notices danger and threats and therefore to focus on these aspects of our world. But what makes us well equipped for our immediate daily surrounding makes us ill-equipped to understand the world around us at large. The consequence of which is that we pay excessive attention to threats and losses and fail to see opportunities and gains.
To balance these biases we have to develop greater sensitivity in measuring opportunities and gains and we have to measure slow changes over time accurately. To develop this clear-eyed view of our world is what scientists around the world are doing. To communicate these gains, opportunities, and slow trends and to make this research accessible for all of us is what OurWorldInData.org aims to do.
As the cognitive scientist Steven Pinker put it when examining why we fail to see human progress: ‘the diagnosis comes from cognitive science and the cure from data science’.

The available evidence for how well informed we are about the world suggests that in important aspects this work is vital. Studies show that the public’s knowledge of how the world is changing in important aspects is sadly rather low. The study ‘Perils of Perception’ published annually by Ipsos MORI, for example, showed how wrong the British public were about some of the most important trends:  One of the findings of the study was that 58% of the British public do not believe that crime is falling, when in fact the ‘Crime Survey for England and Wales’ shows that incidents of crime in 2012 were 53% lower than in 1995.

# To counter fatalism and make us appreciate the progress the world has achieved

Nostalgia for a better past is widespread and many see the world in decline. The chart shows, few of us are optimistic.

# Share of the population who think the world is getting better4


Our World In Data seeks to put this widespread pessimism in context. In the best case people will question their pessimism about the world and it is an initiative that fosters a kind of public optimism. For this effort to succeed we need to present the picture of true progress that we see in the data.  Steven Pinker again“Quantified human progress emboldens us to seek more of it. A common belief among activists is that any optimistic datum must be suppressed lest it lull people into complacency. Instead, one must keep up the heat by wailing about ongoing crises and scolding people for being insufficiently terrified. Unfortunately, this can lead to a complementary danger: fatalism.”

Because our hopes and efforts for building a better future are inextricably linked to our perception of the past it is important to understand and communicate the global development up to now. Studying our world in data and understanding how we overcame challenges that seemed insurmountable at the time should also give us confidence and guidance to tackle the problems we are currently facing. It is easy to be cynical about the world and to maintain that nothing is ever getting better. But fortunately the empirical evidence often contradicts this view. We believe it is partly due to a lack of relevant and understandable information that a negative view on how the world is changing is so very common.
This is the perspective on the world that OurWorldInData presents and the ambition is that seeing the world through this online publication makes more of us appreciate the progress the world has achieved and seek more of it in the future.

# How to use Our World in Data?

We have a page that quickly explains how to use Our World in Data in your presentations, in your writing, and on your web articles and blog: How to use Our World in Data

There you find the information on how to save charts as images, how to embed charts in your articles, and how to use of our work legally.

# The ‘Grapher’

The OurWorldInData–Grapher is at the heart of this publication. It is the tool that allows us to store all data in an online database and then to visualise this data in line charts, maps, bar charts, scatter plots, area charts etc.

As everything else on OWID the Grapher is also completely open source.

You find more – many examples, a video that shows the backend, and everything else – on the OurWorldInData page about the Grapher.

# History of OurWorldInData

In 2011 I started working on this publication by myself. The first idea was to write a book that presents a long-run perspective on global development, but since I found it was difficult to find the empirical literature and empirical data on global development I changed these plans and decided to provide this basic information for everyone online myself. In the following years my supervisor Sir Tony Atkinson and I developed the concept for such a publication, I collected a lot of data to structure and plan this publication. Over the following years this was my project that I worked on on weekends and the evenings. In 2014 I was done with a first basic version of the website and made OurWorldInData available online.

Over the course of 2015 the project was hosted at the Institute for New Economic Thinking and the Department of Economics at the University of Oxford while the financial support was provided by a small research grant from the London-based Nuffield Foundation.
Now, from 2016 onwards this work will be carried out at the University of Oxford’s Oxford Martin School. The Martin School is an interdisciplinary research institution within the University of Oxford and close links between the publication of OurWorldInData and the Martin School already exist. However, funding is only secured for the first 6 months of 2016 and during this period the project has to be successful to secure funding for a longer time horizon, otherwise it will not continue.


The Oxford Martin School was chosen as the institution to host this work as it is a truly interdisciplinary research institution with a focus on the challenges of global development. It is therefore the ideal place to carry out this research.
A small selection of the names of the other programs at the Martin School makes clear that there is a close-knit research environment around OurWorldInData from which this publication can benefit: Global Health, Armed Conflict, Migration, Climate Change, Food, Vaccines, and the Future of Humanity Programme are some of the related programmes.
Collaborations with several of these and other research programs of the Martin School are already established and were already useful in the development of OurWorldInData.org.

The best aspect of the work on Our World In Data was that we are now able to work on this project as a team. The web developer Jaiden Mispy and the research economist Dr Esteban Ortiz Ospina have both made a tremendous contribution to this free online publication. Their work is only possible thanks to the very generous donations that we receive from readers! (You can support our work here.)

# Impact of OurWorldInData

I started preparing this publication in 2011 and in June last year and made the website available online in June 2014. Several hundred thousand readers visit OurWorldInData.org every month. Many articles portrayed the project or used material on global development from OurWorldInData.

English speaking media outlets using OurWorldInData include The New York Times, The Washington Post, Forbes, Slate, Vox, Foreign Policy, Thomson Reuters, The Guardian, Quartz, Bloomberg, World Economic Forum, Business Insider, The Financial Times, and the New Yorker.
Non-English speaking media outlets using OurWorldInData include La Presse (Canada & France), Neue Zürcher Zeitung (Switzerland), Svenska Dagbladet (Sweden), Veja (Brazil), Les Echos (France), Bild am Sonntag (Germany), Polimaty (Poland), Aftenposten (Norway), Rue 89 (France), Blic (Serbia), Chabad (Israel), Scientias (Dutch), Jutarnji (Croatia), Rusplt (Russian), Kushima (Japan), Berlingske (Denmark), Vice (Italy), Contrepoints (France), RPP (Peru), Süddeutsche Zeitung (Germany), Frankfurter Allgemeine Zeitung (Germany), and Der Spiegel (Germany).

We are trying to keep this list of media coverage up-to-date and include all coverage that we are aware.

From the feedback we know that the content of OurWorldInData is used widely in teaching and in lectures. We love when someone uses our work for teaching and it would be great if you would let us know (just a line of what you are teaching and what you are using would be helpful already).

# Sources of data

One of our key tasks in producing this publication is to bring together the best and most informative data sets on a particular topic.

Sources of data that we bring together are published by 3 different sources:

  1. specialized institute – like the Peace Research Institute Oslo PRIO)
  2. research articles – like Bourguignon & Morrison – ’Inequality Among World Citizens: 1820-1992’ in the American Economic Review [2002]
  3. international institutions or statistical agencies – like the OECD, the World Bank, and UN institutions.

# How we choose which data to present

We have 6 guidelines to decide which sources to accept and which data to present.

1) As far back into the past as possible – but up to today
The goal is to give a perspective on the long-term development and therefore we always aim to find time series data that reach back as far as possible. Unfortunately the availability of data is often itself an achievement of modern development and data is not available for the more distant past. A solution for this problem is data that has later been reconstructed and we aim to give a more complete picture by taking this data into account.
At the same time the idea is also to present a ‘history of today’ and we therefore also want to ensure that the data presented reaches until today. The limitation here is often that it takes up to several years for researchers and international institutions to publish important data for the most recent period.
2) As global as possible
A second objective is to give an account of each topic that includes as many societies, countries, and world regions as possible.
3) Present data in its entirety
Shorter sample periods may mask important trends and a recent reversal of a long-term trend could be falsely interpreted as the direction of the long-term trend. The merit of taking a historical perspective that studies long-term trends is that it shows the direction in which some aspect of our world is developing. Therefore we also always ensure to present the whole dataset and we do not want to cut off the original data.
4) Comparable through time and across societies
A third objective is to ensure that the data we present is comparable across time and across societies.

When data is not comparable across countries and through time we highlight this in the text accompanying the visualisation.
5) There is no other data – or we would include this data
An important promise is that we are not withholding any data that would give a different impression of the long-term development of some aspect. If two credible sources would publish statistics that contradict each other – indicating an open debate between researchers – then we would say so.
6) Reference the original source
To make the data base useful for readers and credit the important work of those who construct the data presented here we aim to always reference the original source of the data.

We could very well fail to notice that we violated our own guidelines: If you find that we are not following my own guidelines, or you have any other complaints, please contact us through the form below – click on ‘Give us Feedback’.

# Media Coverage

The media coverage of OurWorldInData.org is now moved to a dedicated page that lists all coverage that we are aware of.

# Authorship of Our World In Data

All content of this publication is licensed under a permissive Creative Commons BY-SA license. Content produced by Our World In Data can be freely used by everyone who finds it useful for their work – including journalists, authors, bloggers, lecturers, or educators.

Author of Our World in Data is Max Roser who founded this publication.

# Disclaimer of warranties and limitation of liability.

To the fullest extent permitted by the applicable law, OurWorldInData offers the websites and services as-is and makes no representations or warranties of any kind concerning the websites or services, express, implied, statutory or otherwise, including, without limitation, warranties of title, merchantibility, fitness for a particular purpose, or noninfringement. OurWorldInData does not warrant that the functions or content contained on the website or services will be uninterrupted or error-free, that defects will be corrected, or that OurWorldInData servers are free of viruses or other harmful components. OurWorldInData does not warrant or make any representation regarding use or the result of use of the content in terms of accuracy, reliability, or otherwise.

Max Roser owns the copyright of the text and the visualizations unless otherwise indicated.

Except to the extent required by applicable law and then only to that extent, in no event will OurWorldInData, or the people working on and related to this website (“the OurWorldInData parties”) be liable to you on any legal theory for any incidental, direct, indirect, punitive, actual, consequential, special, exemplary or other damages, including without limitation, loss of revenue or income, lost profits, pain and suffering, emotional distress, cost of substitute goods or services, or similar damages suffered or incurred by you or any third party that arise in connection with the websites or services (or the termination thereof for any reason), even if the OurWorldInData parties have been advised of the possibility of such damages.
The OurWorldInData parties shall not be responsible or liable whatsoever in any manner for any content posted on the websites or services (including claims of infringement relating to content posted on the websites or services, for your use of the websites and services, or for the conduct of third parties whether on the websites, in connection with the services or otherwise relating to the websites or services.

In case copyright’s infringements are noticed please contact the author Max Roser at