October 10, 2024
When it comes to demographic trends, few are as well known as the “baby boom”.
The baby boom was a sharp rise in the fertility rate toward the end of the Second World War and for decades after. It happened in several countries around the world, but it was especially pronounced in the United States.
Before the baby boom, the US had seen a long-term decline in the fertility rate, down to about 2 children per woman by the 1930s.
During the baby boom, the fertility rate rose sharply, almost doubling to nearly 4 children per woman — levels that hadn’t been seen since the beginning of the 20th century. By the early 1970s, the fertility rate had returned to about 2 children per woman. Today, it’s just over 1.6.
It’s estimated that more than 70 million people were born in the US between 1946 and 1964, the official years of the baby boom according to the US Census Bureau. By 1964, this generation comprised almost 40% of the nation’s population.
As such a large generation, “baby boomers” have played a significant role in shaping many social, economic, and political trends in modern US history.
February 28
In the 1970s, oil spills from tankers — container ships transporting oil — were common. Between 70 and 100 spills occurred per year. That’s one or two spills every week.
This number has fallen by more than 90% since then. In the last decade, no year has had more than ten oil spills, as shown in the chart.
The quantity of oil spilled from tankers has also fallen dramatically. Over the last decade, the average is less than 10,000 tonnes per year, compared to over 300,000 tonnes in the 1970s.
February 26
In the past, forests around the world were cut down on a massive scale. We lost some of the world’s richest ecosystems.
In recent decades, the picture has become more complex. Deforestation has not ended, but it is no longer happening everywhere. Since 1990, some regions have continued to lose large areas of forest, while others have slowed this long-run trend — and even reversed it.
The map shows regional changes in forest area based on the latest data from the Food and Agriculture Organization of the United Nations.
Deforestation has been particularly large in South America and Africa. At the same time, the forested area has expanded in Europe, North and Central America, and large parts of Asia.
These gains show that deforestation is not inevitable. When pressure on land falls, forests can return.
February 24
The Netherlands was the first country to legalize same-sex marriage in 2001. Since then, almost 40 other countries have followed suit.
You can see this in the chart, based on data from Pew Research. By 2025, same-sex marriage was legal in 39 countries.
Last year, two countries were added to the total. Thailand became the first country in Southeast Asia to legalize same-sex marriage, and a same-sex marriage bill also took effect in Liechtenstein.
February 21
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 lives 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 blue, we see the global decline. In red, we see the decline if we exclude China from the data. In the world outside of China, 33% lived in extreme poverty in 1990; by 2025, this share was down to 12%.
The large economic growth that lifted 940 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.
February 19
Forty years ago in Japan, two babies were born for every person who died. Twenty years ago, these numbers were equal. And today, the ratio has reversed: one baby is born for every two people who die.
In the chart, you can see this change in the number of births and deaths over time.
Since deaths now greatly outnumber births, and because immigration is low, Japan’s population has started to shrink.
February 17
Debates over whether religion is booming or dying are common. What does the data say?
Most countries lack long-term data on religious identity, but results from the Pew Research Center offer insights into changes over the decade from 2010 to 2020. (Unfortunately, 2020 is the most recent year for which we have comparable global data.)
At a global level, there was barely any change. The share of people identifying with any religion dropped by just one percentage point, from 77% to 76%.
But religious affiliation did drop significantly across many countries in Europe, the Americas, and Oceania. You can see this drop for a selection of countries in the chart.
In Australia, rates dropped from 75% to 58%. In the United States and Chile, the percentage has decreased from roughly 85% to 70%.
So while religious affiliation is stable in many parts of the world, this data shows religion is becoming less prominent in others.
Note that this data is based on self-identification with any religion; it doesn’t tell us about changes in practices or rituals, such as prayer or attending services.
February 14
This chart shows one way to compare automated manufacturing across countries — it plots the number of robots per 1,000 manufacturing employees.
The chart shows very large differences between countries. South Korea stands out, with more than one robot for every ten manufacturing workers.
Singapore comes second, and China ranks third, close to Germany. The United States sits in the middle, close to the European average, below Switzerland, Denmark and Slovenia.
This perspective shows industrial robot adoption in relative terms. In another Data Insight, I looked at robot adoption in absolute terms. From that perspective, China stands out by a large margin: it’s a large economy with a huge manufacturing sector, and it has by far the largest stock of industrial robots.
Much of this expansion has happened recently: China’s annual installations increased 12-fold over a decade, helping it catch up to South Korea in terms of robots per worker.
