October 15, 2025
Large families used to be the norm in Colombia, but that has changed a lot over just a few generations. I come from Colombia, and my own family reflects this: my grandmother had eleven siblings, my mother had seven, and I have just one sister.
My family is one example of this broader shift within Colombia. In 1950, around the time my mother was born, the fertility rate was 6.4 births per woman. By 2023, it had fallen to 1.6.
That’s what the chart here shows. It plots the total fertility rate: the average number of children a woman would have over her lifetime, if she experienced the observed birth rates of women in her country in the corresponding year. It’s the most widely used measure to track birth patterns across countries and over time.
The chart shows that Colombia’s fertility rate is similar to that of richer countries like France and the UK. It also displays Colombia’s trend alongside China’s for comparison. Perhaps surprisingly, the slope (i.e., the speed) of Colombia’s drop has been similar to China's, despite the latter introducing a one-child policy.
Colombia’s experience mirrors a wider change across many middle-income countries, including much of Latin America. Education of women, urbanization, declining infant mortality, family planning, and changing norms are all key drivers of this trend.
Yesterday
Cervical cancer death rates among women in the United Kingdom have fallen by around 80% since 1950. You can see this reduction in the chart.
This progress happened for a couple of key reasons.
The first was the introduction of population-level screening programs in 1988. Across the UK, women are invited to get a regular smear test to detect precancerous changes or cervical cancer cases early, when treatment has much better odds of success.
Another, and more recent innovation, which could put the UK on the path to eradicating cervical cancer completely, is the rollout of the human papillomavirus (HPV) vaccine. This protects someone from the HPV infection, which can later develop into cervical cancer.
In schools across the country, girls in their early teens are offered the HPV vaccine, effectively offering them long-lasting protection. I was one of the first cohorts of girls in the UK to receive this, and it’s something I’m incredibly grateful for.
The UK is not alone in its progress: a number of countries have managed to reduce cervical cancer death rates in recent decades.
April 16
France generates two-thirds of its electricity from nuclear power, making it the country’s dominant power source.
As the chart shows, that’s far more than the average across Europe, which is 20%, and the world as a whole, at 9%.
Nuclear power is a low-carbon electricity source, giving France a very clean electricity mix for decades.
Per unit of electricity, France emits far less greenhouse gas than its neighbors and has some of the lowest-carbon power in the world. The global average, based on lifecycle emissions, is 472 grams of carbon dioxide equivalents (CO2e) per kilowatt-hour of electricity generated. In France, this figure is 42 grams.
April 14
In every region of Africa, hunger is more prevalent than a decade ago.
The chart shows the increase in the share of the population that is undernourished, comparing 2014 and 2024 (the most recent year available). These estimates come from the Food and Agriculture Organization of the United Nations.
The situation across Africa is dire. In Middle Africa, where hunger is most acute, almost 1 in 3 people are undernourished. In Eastern Africa, the figure is roughly 1 in 4. Across Africa as a whole, it's 1 in 5.
This marks a reversal of a longer positive trend: over the preceding decades, hunger had been falling across much of the world, including parts of Africa. That progress has now stalled or gone into reverse. Conflict, extreme weather, and the economic disruption of the COVID-19 pandemic have all contributed.
April 11
The concept of “leapfrogging” is popular in development. It suggests that, as they develop, lower-income countries can skip intermediate technologies or systems and 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.
But many countries have almost skipped landline adoption entirely. Ghana and Nigeria are good examples: landline subscriptions have remained extremely low, and instead, mobile phone adoption has exploded.
April 9
Even after years of working with global health data, one statistic that I’m always struck by is the number of people who die by suicide every year. In 2023, it was estimated to be around three-quarters of a million.
That means suicides account for more than 1 in every 100 deaths in the world.
But a world where so many die from suicide is not inevitable. We know this because global suicide rates have fallen by an estimated 40% since the 1990s.
You can see this in the chart: rates have fallen from 15 to 9 deaths per 100,000 people over the last thirty years.
The large differences between countries also suggest that there are things that can be done to reduce this number even further.
April 7
Some technologies central to the clean energy transition depend on rare earth elements. The permanent magnets found in many electric vehicle motors and wind turbine generators rely on them. They are also used in some military hardware.
China dominates global production of rare earths; in 2024, it accounted for nearly 70% of the global total.
But the picture is not as concentrated when you examine which countries have rare-earth reserves. That is what the chart shows, plotting production and reserve shares side by side. China still holds the most known reserves, but at 49%, this is substantially lower than its production share.
Brazil holds 23% of reserves and is barely mining them. India, Vietnam, and Russia also hold significant reserves, but only a small fraction of current output.
The large gap between where reserves are located and where mining occurs partly reflects China's early investment in mining infrastructure and processing capacity, which other producers have not yet matched. Other countries hold the geological potential but have not yet developed the infrastructure to convert it into production at scale.
April 4
Child mortality rates in China have fallen from more than 20% in 1950 to less than 1% today.
But this steady progress was interrupted in the late 1950s during the “Great Leap Forward”. This was China’s national plan to industrialize rapidly, but it resulted in widespread famine and economic turmoil.
As the chart shows, child mortality rates spiked in China over this period, with up to one in three children dying before reaching the age of five. This change was so dramatic that it is also clearly visible in the global trend.
This data comes from the UN’s World Population Prospects.
