The limits of our personal experience and the value of statistics
The world is huge; to get a clear idea of what our world is like, we have to rely on carefully collected, well-documented statistics.
July 27
Article
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Our latest articles, data updates, and announcements
July 18
Article
SDG Tracker: Measuring progress towards the Sustainable Development Goals
Our World in Data’s Sustainable Development Goals Tracker
July 11
Article
How are incomes adjusted for inflation?
Adjusting incomes for inflation is crucial if we want to learn how standards of living are changing. How is this adjustment done?
July 06
Article
How has income inequality within countries evolved over the past century?
While the steep rise of inequality in the United States is well-known, long-run data on the incomes of the richest shows countries have followed a variety of trajectories.
July 06
Article
OWID Data Collection: Inequality and Poverty
Explore a wide range of indicators on inequality and poverty and compare sources.
July 03
Article
Income inequality before and after taxes: how much do countries redistribute income?
The redistribution of income achieved by governments through taxes and benefits varies hugely.
June 30
Article
Measuring inequality: what is the Gini coefficient?
The Gini coefficient is the most common way of measuring inequality. But what does it actually measure? And how does it differ from other measures of inequality?
June 26
Article
Homicide data: how sources differ and when to use which one
There are several ways to measure homicides. What approaches do different sources take? And when is which approach best?
June 02
Article
Population momentum: if the number of children per woman is falling, why is the population still increasing?
50 years ago, the total fertility rate was five. This figure has more than halved. Yet the global population is still rising — why?
May 26
Article
How do researchers study the prevalence of mental illnesses?
Global data on mental health is essential to understand the scale and patterns of these illnesses, and how to reduce them. How do researchers collect this data, and how reliable is it?
May 26
Article
How are mental illnesses defined?
Mental illnesses are a range of conditions that significantly affect people’s lives. What are their symptoms?
April 27
Article
How is food insecurity measured?
Billions of people suffer from food insecurity. What does it mean to be food insecure?
April 18
Article
Learning curves: What does it mean for a technology to follow Wright’s Law?
Technologies that follow Wright’s Law get cheaper at a consistent rate, as the cumulative production of that technology increases.
April 11
Article
Mortality in the past: every second child died
The chances that a newborn survives childhood have increased from 50% to 96% globally. How do we know about the mortality of children in the past? And what can we learn from it for our future?
April 04
Article
How does age standardization make health metrics comparable?
Age standardization is a statistical method used to compare disease rates, or other health indicators, between populations while accounting for differences in their age structure.
March 29
Article
Artificial intelligence has advanced despite having few resources dedicated to its development — now investments have increased substantially
The available resources have increased substantially. We should expect that the field continues to advance rapidly.
March 28
Article
What is Moore's Law?
Exponential growth is at the heart of the rapid increase of computing capabilities.
March 18
Article
Two centuries of rapid global population growth will come to an end
Global population has increased rapidly over the past century. This period of rapid growth is temporary: the world is entering a new equilibrium and rapid population growth is coming to an end.
March 13
Article
What is the ozone layer, and why is it important?
Over the last 50 years, holes in the ozone layer have opened up. Why does that matter for life on Earth?
February 28
Article
Our World in Data will rely on data from the WHO to track confirmed COVID-19 cases and deaths
Johns Hopkins University will stop publishing data on confirmed COVID-19 cases and deaths. Our team will replace our entire time series with WHO's data on 8 March 2023.
February 27
Article
How we choose which topics to work on, and which metrics to provide
On Our World in Data, we present thousands of metrics on hundreds of topics. How do we choose them?