Daily Data Insights
Bite-sized insights on how the world is changing, published every weekday.
May 29, 2024
Airline hijackings, once relatively common, are rare today
Airline hijackings are often considered a very visible and prominent form of modern terrorism, with the 9/11 attacks in the United States in 2001 being a well-known tragic example.
Historical data from the Aviation Safety Network shows that airline hijackings have a long history but have become much less frequent than in the past.
Between 1968 and 1972, hijackings reached a peak, with over 305 incidents recorded globally within those five years.
In 2021, the most recent year with available data, there were 3 incidents, none involving fatalities.
May 28, 2024
On average, people have lived much longer than the period life expectancy at their time of birth
The data on this chart comes from the Human Mortality Database.
It shows that in 1930, people in France had a period life expectancy of 57 years. Period life expectancy is a metric that summarizes age-specific mortality rates in one particular year. This means that newborns would live 57 years on average if they experienced the same death rates at each age of their lives as those seen at each age in the population that year.
However, these newborns actually faced lower death rates than previous generations and lived an average of 69 years. This second measure — the average lifespan of a birth cohort — is called cohort life expectancy. It can only be calculated once all cohort members have died.
Period life expectancy is the more commonly reported “life expectancy” measure. However, these two measures are very different, and the gap can be large, as this data shows.
Read more on the difference between period and cohort measures →
May 27, 2024
One in five democracies is eroding
Based on the Episodes of Regime Transformation data, this chart shows that around 20% of democracies were slowly deteriorating in 2023.
According to the underlying expert assessments by country experts, elections are becoming less meaningful, free, or fair in these countries.
This rate of democratic erosion is unprecedented.
This is partly because the data seeks to capture gradual declines in democratic institutions, while historically, democracies often broke down rapidly in coups d’état or foreign invasions.
So, while political rights are under threat in a substantial share of democracies, there is still time to act to halt this decline, restore democratic rights, and even deepen democratic institutions.
If you want to learn more, you can read my article on recent changes in democracy, for which we just updated the data.
May 24, 2024
There are huge inequalities in global CO2 emissions
Richer people tend to have a higher carbon footprint. They consume more energy, and since much of it still comes from fossil fuels, they have much higher carbon emissions than those on lower incomes.
This inequality is clear when we examine countries' contributions by income level. The chart above shows the four World Bank income groups’ share of global carbon dioxide (CO2) emissions and population, using data from the Global Carbon Project. The groups are based on the average income at the country level — they don’t account for differences between people’s incomes within each country.
High-income countries contribute more than twice their share of the global population: they are home to just 15% of people but emit 34% of global emissions. Low-income countries are home to 9% of the global population but emit less than 1% of total emissions.
This gap increases by several percentage points when we account for emissions embedded in traded goods.
May 23, 2024
In less than a decade, Peru has become the world's second-largest blueberry producer
Between 2012 and 2022, Peru's blueberry production went from less than a thousand tonnes to nearly 300,000 tonnes per year.
According to estimates from the UN Food and Agriculture Organization, this huge growth in output was enabled by a rapid expansion in the land used to grow blueberries, together with substantial gains in the number of tonnes produced per cultivated hectare.
These trends show that significant agricultural changes can happen very quickly.
Explore the world's food system crop-by-crop from production to plate →
May 22, 2024
Much more progress can be made against child mortality
The world has made great progress against child mortality. But in many countries, a significant share still die during childhood.
The data on this map comes from the UN IGME, which estimates child mortality rates worldwide using detailed household surveys and vital statistics.
As the map shows, child mortality is much lower in rich countries, where fewer than 1% of children die before the age of five.
However, the figures are much higher in poor countries, especially across Africa and South Asia. In Pakistan, for example, 6% die before their fifth birthday. In Nigeria and Somalia, the figure is 11%.
These statistics show that despite impressive falls in child mortality, much more progress can be made.
Child mortality: an everyday tragedy of enormous scale that we can make progress against
We live in a world in which 10 children die every minute.
May 21, 2024
The price of computer storage has fallen exponentially since the 1950s
This chart shows the dramatic fall in the price of computer storage between 1956 and 2023. It relies on the data carefully collected by the computer scientist John C. McCallum.
In the last 70 years, the price for a unit of storage has fallen by almost ten orders of magnitude. The data is plotted on a logarithmic scale on the vertical axis. The line follows an almost straight path, indicating an exponential reduction in price.
A 256-gigabyte storage capacity — commonly found in standard laptops sold today — would have cost around 20 billion dollars in the 1950s. (That’s in today’s prices.)
And cost has not been the only improvement: modern solid-state drives offer much faster and more reliable data access than early magnetic and hard disk drives.
Read more on the exponential growth of computing capabilities →
May 20, 2024
In the last 200 years, many countries have built institutions to collect statistics on their populations
Governments need accurate information about their populations to implement effective policies.
But historically, few countries collected basic statistics on their people, so they knew little about them.
The chart here shows that, over time, many countries have built such institutions.
Starting in the 19th century, they began conducting population censuses, creating civil registers, and establishing statistical agencies. In the later 20th century, they started setting up population registers and using register-based censuses.
Thanks to these efforts, these countries better understand where people live, what jobs they have, who was born, and who has died.
However, many countries still lack these institutions, which makes it challenging for them to direct projects and policies where they are most helpful.
May 17, 2024
More than 30 countries have legalized same-sex marriage
The Netherlands was the first country to legalize same-sex marriage in 2001. Since then, more than 30 other countries have followed suit.
You can see this in the chart, based on data from Pew Research. By 2022, same-sex marriage was legal in 32 countries.
Since then, 3 more countries have joined this group: Andorra, Estonia, and Greece — bringing the total to 35. Last year, Nepal also registered its first same-sex wedding, but it’s not yet clear whether these rights are available across the country.
May 16, 2024
Global population growth peaked six decades ago
The increase in the world’s population is not exponential. The global population is growing, but the growth rate has declined since its peak six decades ago.
The chart shows the annual rate of global population growth according to historical estimates and projections from the UN World Population Prospects.
The growth rate peaked in 1963 at over 2% per year, and since then, it has more than halved, falling to less than 1% by 2020.
The UN demographers expect rates to continue falling until the end of the century, eventually leading to negative growth rates and a shrinking global population.
May 15, 2024
Drug-resistant tuberculosis is much more expensive to treat
Tuberculosis is usually treatable with a specific combination of antibiotics. However, without proper treatment, the bacteria can survive and develop antibiotic resistance to an increasing number of drugs. This drug-resistant bacteria can then spread to other people, making the disease much more expensive to treat.
The chart shows the cost of treating a single patient with tuberculosis in India.
For tuberculosis patients without drug resistance, the average cost of treatment is only $24.
But among patients who have multi-drug resistant tuberculosis, the cost is almost $400. With extensively drug-resistant tuberculosis, it costs more than $1,000. That’s about 50 times higher than patients without drug resistance.
May 14, 2024
The share of democracies has recently stagnated but remains near its historical high
Over the last twenty years, the share of countries that are democracies has remained relatively stable.
Relying on data from Varieties of Democracy, which we just updated, the chart shows that around half of all countries are democracies.
The world remains close to the historical high in the early 2000s and is much more democratic than 50 years ago; only 20% of countries were democracies in the early 1970s.
However, the chart shows smaller changes within democratic regimes: the share of liberal democracies, which grant additional individual and minority rights and constrain their governments, has decreased over the last decade.
While democracy has remained fairly resilient over the last few decades, this recent stagnation and limited rollback stresses that progress on increasing political rights is neither linear nor guaranteed.
May 13, 2024
Commercial flights have become significantly safer in recent decades
According to figures from the Aviation Safety Network, in the 1970s, there were about 6 fatal airliner accidents for every million commercial flights. This meant about 1 in every 165,000 flights ended in a fatal accident.
As the chart shows, this figure has dropped steadily in the last 50 years. According to the latest data, it is now about half a fatality per million flights. This means that, on average, it now takes more than 2 million flights for a fatal accident to occur.
May 10, 2024
Sulfur dioxide emissions from shipping dropped sharply with the introduction of new rules in 2020
The Community Emissions Data System (CEDS) produces invaluable long-term data on the emissions of air pollutants worldwide. It has just published its latest update, extending this data to 2022.
One of the most striking changes in air pollution trends has been the abrupt drop in sulfur dioxide (SO2) emissions from shipping. As you can see in the chart — where shipping is highlighted in red — there was a dramatic fall from over 10 million tonnes a year in 2019 to 3 million tonnes a year later.
The change resulted from the International Maritime Organization’s strict limits on marine fuels, introduced in 2020: the maximum percentage of sulfur allowed in these fuels fell from 3.5% to 0.5%. All ships worldwide had to comply.
This drop is positive for tackling local air pollution and acid rain. However, it also has implications for climate change since SO2 has masked some of the warming caused by greenhouse gases.
May 09, 2024
Testing rates for polio have rebounded after a drop amid the COVID-19 pandemic
The world is close to eradicating polio. Annual cases have dropped from an estimated 400,000 in the 1980s to less than 4,000 in recent years.
But, to cross the finish line, sufficient testing is crucial to ensure that cases aren’t missed.
The World Health Organization recommends that at least 80% of potential polio cases be tested for the virus. Potential cases are identified based on “acute flaccid paralysis”, a sudden onset of paralysis in the limbs.
As shown in the chart, disruptions from the COVID-19 pandemic led to a drop in polio testing rates in many countries. Thankfully, this new data shows that polio testing has rebounded.
This is due to the dedicated effort of countless health workers and opens the way to a future free from polio.
May 08, 2024
30% of the world's electricity came from renewable sources in 2023
Renewable electricity production is growing quickly, mostly thanks to the deployment of solar and wind.
Ember has just published its latest Global Electricity Review, which includes final updates on electricity generation worldwide in 2023. We have updated our Energy Data Explorer with all of this data.
As the chart shows, renewables produced just over 30% of the world’s electricity in 2023.
This growth was mostly driven by the rapid rollout of solar and wind technologies. Hydropower generation actually fell in 2023 as a result of severe droughts, especially in China.
May 07, 2024
The rise of tax revenues in Southern Europe
Southern Europe demonstrates that countries can substantially increase the taxes they collect in a relatively brief period of time.
The chart shows that in 1980, tax revenues in Greece, Portugal, and Spain accounted for around 20% of their respective GDP, based on data from UNU-WIDER. This was slightly less than the United States’s 25% of GDP and much lower than Germany’s 36%.
Within a few decades, the three countries greatly increased their tax revenues. By 2021, they had almost caught up with Germany, with revenues nearly 40% of GDP. Even the 2007–2008 economic crisis only briefly interrupted their upward trend.
This shows that governments can increase their tax collection to expand public policies, even in countries where taxes were comparatively low in the past.
May 06, 2024
The age structure of populations varies widely across countries
There are many ways to examine a country's age structure. One interesting approach is to look at the age group with the largest population, as shown in the world map.
Across most African countries, the largest demographic is children younger than 10.
This contrasts sharply with Europe, where the largest age groups tend to be much older. Many European countries are most heavily populated by those in their 30s, 40s, and 50s. For example, the fifties are the largest age group in the United Kingdom and the Netherlands. In Monaco and Croatia, the most populous are those in their sixties.
If we look back to 1950, the map looks very different. Small children and teenagers were the most populous age groups in almost all countries.
Over the last 70 years, birth rates have declined in most countries, and life expectancy has increased, leading to aging populations worldwide.
May 03, 2024
Was the global decline of extreme poverty only due to China?
The share of the world population living in extreme poverty has never declined as rapidly as in the past three decades.
The decline in China was particularly fast, and given that one in six people in the world live there, we’re often asked whether the decline in global poverty was only due to the decline in China.
The chart shows the data that answers this question. In red, we see the global decline. In green, we see the decline if we exclude China from the data. In the world outside of China, 29% lived in extreme poverty in 1990 — by 2022, this share was down to 11%.
The large economic growth that lifted 800 million Chinese people out of extreme poverty since 1990 was a major contributor to the global decline in poverty. But the non-Chinese world also achieved a very large reduction.
It is not true that the global decline in poverty was only due to China. Extreme poverty has declined in China and the rest of the world.
May 02, 2024
Data on suicides is lacking, especially from poorer countries
Many countries do not collect or publish national data on suicides, especially poorer countries.
Around 60% of high-income countries have shared data on annual suicide rates in a given year with the World Health Organization, but less than 20% of lower-middle-income countries do, and no low-income countries have done so since 2011.
This lack of data is partly due to an absence of vital registries — where death certificates are collected — and coroners, doctors, and legal systems to determine and record causes of death across the population.
Without this data, statistical organizations estimate suicide rates based on other data, such as surveys and data from similar countries. This is challenging because suicide is highly stigmatized in many countries and sometimes even criminalized.
The chart also shows that more countries have improved their data collection and reporting systems. With more effort to improve vital registries, we will gain a greater understanding of where and why suicides occur, who is at risk, and how to prevent this tragic cause of death.