Data Insights
Bite-sized insights on how the world is changing, written by our team.
More countries have legalized same-sex marriage, but others have explicitly banned it
While some countries have granted more rights to LGBT+ people, others are moving in the opposite direction.
The chart, based on data from researcher Kristopher Velasco, shows that five countries had an explicit ban on same-sex marriage in 1991. Their laws did not just say nothing about same-sex marriage; they had laws that made it explicitly illegal.
By 2019, this number had increased to 37 countries, concentrated in Eastern Europe and Sub-Saharan Africa.
These marriage bans have happened while a similar number of countries have legalized same-sex marriage.
In this way, LGBT+ rights have become more polarized: some countries have introduced progressive laws, while others have become more regressive.
Indoor air pollution causes over three million premature deaths every year
Most of the world's poorest people still rely on solid fuels — such as crop waste, dung, wood, and charcoal — for cooking and heating.
These fuels cause damaging air pollution in households when they’re burned.
According to estimates from the Institute for Health Metrics and Evaluation, indoor air pollution prematurely kills more than three million people each year.
As shown on the chart, deaths from indoor pollution are falling as more people get access to cleaner cooking fuels. Improving access to clean energy could prevent many more early deaths.
Funding to study neglected tropical diseases and develop new technologies is very limited
This chart shows the amount of annual funding for research and development (R&D) to understand, treat, and develop technologies against neglected tropical diseases (NTDs). This data comes from Policy Cures Research’s G-FINDER project.
Less than $100 million is spent on R&D for most NTDs, despite millions of people being affected by these diseases — which include dengue, leishmaniasis, and trachoma.
Without funding, it’s very difficult to develop new medicines, vaccines, and technologies to reduce suffering and disability for the millions of people affected by these diseases.
We know that effective funding works. Large public health initiatives have helped fund research against HIV/AIDS, tuberculosis, malaria, and COVID-19 and have saved millions of lives.
People’s self-reported life satisfaction varies widely across countries
How satisfied are people with their lives? Answering this question can give us important insights into what matters to people and the circumstances that lead to a fulfilled life.
The World Happiness Report has published data on life satisfaction — based on the Gallup World Poll — since 2012 and covers more than 140 countries worldwide. We have just updated our charts with the latest data.
It measures life satisfaction by asking people to rate their lives on a ladder from 0 to 10, where their worst possible life is 0 and their best possible life is 10.
The resulting score is averaged over the last three years to focus on longer-term shifts.
Despite drastic experiences like the COVID-19 pandemic, overall life satisfaction remains remarkably consistent globally. We can also observe correlations with other measures of well-being: healthier and richer countries tend to have higher average life satisfaction scores.
COVID-19 was the third largest cause of death in 2021
According to the latest Global Burden of Disease Study — published last month by the Institute of Health Metrics and Evaluation (IHME) — COVID-19 was the third leading cause of death in 2021, after cardiovascular diseases and cancer.
These estimates suggest that COVID-19 was responsible for around eight million deaths in 2021. In many countries across South America and sub-Saharan Africa, the IHME reports that it was the leading cause of death.
Global improvements in healthcare have led to a steady reduction in the death rate from infectious diseases in recent decades, but the COVID-19 pandemic has reversed this trend.
How much of national income goes to the richest 1%?
Globally, there are large differences in the estimated share of income received by the richest 1% of the population. In Norway and Slovakia, it’s 7%; 27% in Mexico, and 31% in Mozambique and the Central African Republic.
You might expect these numbers to be strongly correlated to a country's level of economic development. But this isn't always the case. In the United States, for example, 1% of its population takes home 21% of national income. This is relatively high globally.
The data comes from the World Inequality Database, and we just updated our charts with their latest data. The data above is based on income before taxes and benefits, but after-tax incomes show a broadly similar inequality map.
The ozone hole over the Antarctic grew rapidly in the 1980s, but stopped growing in the late 1990s
The ozone hole over Antarctica was growing rapidly throughout the 1980s and early 1990s, as the data in the chart shows. At its largest, the ozone hole was more than 25 million square kilometers — slightly bigger than the size of Sub-Saharan Africa.
The earth’s ozone layer is important as the ozone absorbs most of the sun’s ultraviolet radiation, and helps to keep Earth habitable. Human emissions of ozone-depleting substances — mostly chlorofluorocarbons — were breaking down ozone high in the atmosphere.
But in 1987, the world agreed to phase out these ozone-depleting substances by signing the Montreal Protocol. Since then, emissions have fallen close to zero.
As a consequence, the ozone hole stopped growing in the late 1990s. It will take decades to recover fully, but it’s slowly starting to rebuild.
Family is very important to people around the world
Most people agree that family is very important, no matter where they live.
Using data from the European Values Study and World Values Survey, the chart shows that a large majority of people worldwide declare family to be important in their lives. This share is above 80% in every country except six.
Only a small percentage of people say they find family “not very important” or “not important at all”.
Despite our disagreements, we should remember how much people across countries and cultures agree on what truly matters to them.
Coal power is dying in Western Europe
Coal dominated Europe's electricity mix over the 20th century, but it is quickly dying in many countries in the 21st.
The chart shows the share of electricity that comes from coal for a range of countries in Western Europe. The data comes from Ember.
Transitioning away from coal has helped reduce carbon emissions and local air pollutants.
Extreme poverty, though lower than in the past, is still very high in Sub-Saharan Africa
The United Nations’ first Sustainable Development Goal is to “end poverty in all its forms everywhere” by 2030. The world is still very far away from this goal.
The data from the World Bank shows that in 1990, 55% of the population in Sub-Saharan Africa and 65% in East Asia and the Pacific lived in these conditions — broadly similar figures. But the most recent figures were 37% in Sub-Saharan Africa and 1% in East Asia and the Pacific.
The United Nations focuses on “extreme poverty” in its Sustainable Development Goals agenda. They define this as living with less than $2.15 per day. This figure represents what $2.15 could buy you in the United States in 2017 prices; it is adjusted for inflation and cost of living differences between countries.
Human rights have improved in all world regions over the last century
Human rights are much better protected in all world regions than a century ago, according to data by Varieties of Democracy.
This recently updated chart shows an index that captures human rights. The index ranges from 0 (least rights) to 1 (most). As you can see, every world region scored significantly higher in 2023 than 100 years ago.
Although progress has not been steady, and there have been setbacks — including in recent years — the overall improvements have been substantial. These trends remain when giving more weight to countries with larger populations.
While progress has been made in all world regions, there are still big disparities across them, with Africa and Asia lagging behind. And the strong protections on other continents show that further global progress is possible.
Solar panel prices have fallen by around 20% every time global capacity doubled
One of the most transformative changes in technology over the last few decades has been the massive drop in the cost of clean energy. Solar photovoltaic costs have fallen by 90% in the last decade, onshore wind by 70%, and batteries by more than 90%.
These technologies have followed a “learning curve” called Wright’s Law. This states that the cost of technology falls consistently as the cumulative production of that technology increases.
The chart shows the perfect example of this for solar power. This data comes from the International Renewable Agency, Greg Nemet, and Doyne Farmer & François Lafond.
On the horizontal axis, we have the cumulative installed capacity of solar panels, and on the vertical axis, the cost. Both are measured on logarithmic scales, and the trend follows a straight line. That means the fall in cost has been exponential.
Costs have fallen by around 20% every time the global cumulative capacity doubles. Over four decades, solar power has transformed from one of the most expensive electricity sources to the cheapest in many countries.
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.
The price of lighting has dropped over 99.9% since 1700
In the last two centuries, the price of lighting has decreased drastically.
You can see this in the chart, which plots historical data from Roger Fouquet and Peter Pearson. To allow for comparisons over time, the data is adjusted for inflation and expressed in prices for the year 2000.
In the 1300s, one million lumen-hours — a standard lighting measure — would have cost around £40,800 in 2000 prices. By 2006, this had fallen to £2.90, a 14,000-fold decline.
Innovations in lighting appliances, fuels, infrastructures, and institutions during the 19th and 20th centuries made this progress possible.
To put this in perspective, consider that a standard 100-watt incandescent light bulb today can emit about 1,700 lumens. Therefore, running one such bulb for 24 hours would produce about 50,000 lumen-hours. That means that 1 million lumen-hours today would require continuously keeping a standard 100-watt incandescent bulb on for about 25 days. Achieving the same amount of light with candles would require burning more than 100 candles every day for that period.
Most people today take the ability to switch on a light at night for granted. But those who live or have lived without artificial light can appreciate how important it is.
Homicide rates have declined dramatically over the centuries
It is hard to imagine just how violent the past was.
The chart shows that in the 13th and 14th centuries, based on data from researcher Manuel Eisner, homicide rates across Western Europe were higher than 10 murders per 100,000 people in a year. In Italy, the rate was as high as 70 murders per 100,000 people.
Since then, murder rates have fallen significantly across these countries. According to data from WHO’s Mortality Database, their homicide rate is now around 1 murder per 100,000 people — less than a tenth of what it used to be.
Despite these improvements, homicides remain a common cause of death globally and are even a leading cause in some countries. But significant and lasting reductions in violence between people are possible.
Which countries have fertility rates above or below the “replacement level”?
Fertility rates — which measure the average number of children per woman — have been falling worldwide. Since 1950, global fertility rates have halved, from almost 5 children per woman to 2.3.
As a result, global population growth has slowed dramatically, and many countries' populations are expected to decline by the end of the century.
This is because fertility rates in many countries have fallen below the “replacement level”. This is the level at which a population replaces itself from one generation to the next. It’s generally defined as a rate of 2.1 children per woman.
The map shows which countries had fertility rates above and below this level in 2021. This is based on estimates from the UN World Population Prospects.
Core LGBT+ rights are becoming more protected in some countries
Important LGBT+ rights are becoming better protected in some countries, according to the work of researcher Kristopher Velasco.
The chart shows that in the early 1990s, very few countries protected LGBT+ rights beyond allowing same-sex sexual acts. Back then, no countries allowed same-sex partners to marry or adopt children, none recognized a third gender, and only two made it easy to change one’s gender marker legally.
Over the last few decades, more countries have offered and protected these rights. Most countries have now legalized same-sex relationships, and same-sex marriage, adoption, third-gender recognition, and gender marker changes are becoming more common. However, most countries still do not recognize these important rights.
Many countries are “leapfrogging” landlines and going straight to mobile phones
The concept of “leapfrogging” is popular in development. It suggests that lower-income countries can, as they develop, skip intermediate technologies or systems to go straight to the modern equivalent.
One example of this is the use of landlines and mobile phones.
The landline telephone was invented in 1876 and became a dominant form of communication across Europe and North America. As you can see in the chart, it was increasingly adopted in the United States and the United Kingdom throughout the 20th century.
However, mobile phone adoption increased rapidly in the 1990s, and landlines have declined since the millennium. Mobile phones have become a substitute for landlines.
Many countries, however, have almost skipped the adoption of landlines entirely. India, Ghana, and Nigeria are good examples: landline subscriptions have remained extremely low, and instead, mobile phone adoption has exploded.
Deaths from tetanus have been reduced massively
Tetanus is a bacterial disease that causes paralysis and can lead to death.
Globally, it was estimated to kill more than 250,000 people each year in the early 1990s. Most of these deaths were in children.
By 2019, annual deaths had fallen to less than 35,000.
The rollout of the combined vaccine against diphtheria, tetanus, and pertussis (DTP) among children has been crucial in driving this.
Mobile money accounts are surging globally, especially in Africa and Asia
Mobile phones and the Internet have enabled the growth of mobile money accounts in regions with limited banking infrastructure. These accounts provide simple financial services like deposits, transfers, and payments to hundreds of millions of people.
As this chart shows, the number of active mobile money accounts globally has grown from 13 million in 2010 to more than 640 million in 2023. This is based on data published by the GSM Association.
While the adoption of mobile banking was almost exclusive to Sub-Saharan Africa in the early 2010s, Asian countries have seen significant growth in recent years.
There are large differences in LGBT+ rights across the world
As shown on his map — based on an index calculated by researcher Kristopher Velasco — LGBT+ rights vary greatly between countries.
The index combines information on 18 policies, including same-sex relationships, marriage, and gender markers. Higher values indicate more and better-protected rights; negative values represent regressive policies.
In some countries, people can legally be in same-sex relationships, get married, and adopt children. But in many others, LGBT+ rights are poorly protected, or policies are regressive. Some countries explicitly ban same-sex marriage or impose severe punishments, including the death penalty, for same-sex relationships.
While some countries have made progress in protecting LGBT+ rights, most still have a long way to go to achieve equality.
Explore differences in LGBT+ rights across countries and over time →