In the 1980s, youth literacy was higher in Sub-Saharan Africa than in South Asia; it’s now the opposite

When I first visited Buenos Aires some years ago, I was struck by how grand the city's historic architecture was. This is something that strikes many tourists: parts of the city feel closer to Paris than you’d expect from a country whose income level today is more similar to my home country of Colombia than to France.

This chart helps put that observation in perspective. It shows the ten richest countries in the world in 1910, according to GDP per capita estimates from economic historians.

By this measure, Argentina was among the world’s richest countries in 1910, ahead of several Western European countries, including Germany and France. It also stood clearly ahead of its peers in Latin America at the time.

But over the course of the 20th century, Western European economies grew far faster, especially after the Second World War, and Argentina fell behind.

A long-run perspective like this shows how much of a difference economic growth can make within just a few generations.

In 1965, the median age in the United Kingdom was almost twice that of China. Half of the people in the UK were younger than 34 years, and half were older. In China, this midpoint was just 18 years.

Within just a few generations, that age gap has closed.

As you can see in the chart, the median age in both countries is now 40 years. Both populations have aged, but the increase was far faster in China.

In the 1950s and early 1960s, China’s median age fell partly because of a fall in child mortality: birth rates remained high, and more children survived.

After that, the rapid increase is largely explained by a steep fall in fertility, and therefore in births. Before then, high birth rates meant that large cohorts of children were continually entering the population, keeping it young. When births fell, fewer children were added each year, and the large, earlier generations grew older.

China’s median age is expected to continue rising quickly: under the UN’s medium projections, it will be 10 years older than the UK's by 2050.

Throughout the entire 20th century, about 100 million people died earlier than they would have because of smoking. That’s a lot, but it pales in comparison to the expected numbers for this century.

Between 2000 and 2023 alone, smoking-related deaths are estimated at 163 million. You can see this comparison in the chart.

Some epidemiologists project that unless there is a substantial change in smoking uptake and rates across the world, there could be as many as one billion smoking-related deaths in the 21st century.

In the 20th century, most of these occurred in today’s high-income countries. In the 21st century, most will come from low- and middle-income countries.

Many of the people who are expected to die are smoking today, but even more are expected to be future smokers. Finding ways to help people stop smoking and prevent them from starting matters for keeping this huge figure in the millions, not billions.

At the turn of the millennium, 2.2 billion people in the world lived in extreme poverty. In international statistics, this means they survived on less than $3 per day (in today’s money).

In the two decades that followed, this number more than halved. You can see this decline in the chart.

This huge reduction was driven by rising incomes and poverty alleviation across East and South Asia. In Sub-Saharan Africa, the opposite happened: while the share living in extreme poverty declined, the total number increased.

Looking ahead, based on the latest available projections from researchers at the World Bank, this reduction in global extreme poverty is expected to end. In fact, numbers in 2040 might be higher than they are today.

This is because most of the extremely poor today live in countries with stagnant economies. If these do not see much stronger economic growth, the world will have nearly one billion living in dire poverty for decades to come.

Note that these projections are based on the latest growth projections from the World Bank and the IMF. From 2031 onward, poverty projections are based on the average growth rates observed from 2015 to 2024.

Just a decade ago, almost three times as much electricity in the European Union was coming from fossil fuels as from solar and wind.

But last year, for the first time, solar and wind produced more than coal, gas, and oil combined. They accounted for just over 30% of total electricity production.

You can see this rise of solar and wind — and fossil fuels’ decline — in the chart.

This record happened despite a poor year for wind output due to low wind speeds and a slight increase in gas to compensate for lower hydropower output from dry conditions.

Marriage is closely linked to decisions about having children in many societies. It also matters for legal rights, family finances, and many other aspects of life.

The age at which people marry has rapidly changed in many countries. The chart shows this by tracking the average age at first marriage among women, using records from national statistics.

In Portugal, Italy, and Spain, the average age at first marriage has risen rapidly and consistently. Portugal saw the largest increase: from around 26 years in 2002 to over 32 years by 2020. This is more than six years in less than a generation. It’s also the largest increase among the countries in the OECD Family Database with data available from the early 2000s up to 2020 (the most recent year with available data in the series).

Changes in the timing of marriage have come together with other related shifts. For instance, a growing share of people are not marrying at all.