Read the full transcript of data scientist and demographer Stephen J Shaw’s talk titled “Everything You Know About Overpopulation Is Wrong” at The Alliance for Responsible Citizenship (ARC) conference [Feb 24, 2025].
Listen to the audio version here:
STEPHEN J SHAW: “I was haunted by the future I might not have.” Those were the words from a young 25-year-old Cambridge University student after watching this documentary. She contacted me a few weeks later to explain that after hearing that no more than half of women turning 30 without a child ever become mothers, she was angry. For two weeks she went for walks thinking about why she didn’t know this, having plotted her entire life around assuming she’d meet the right man around age 35 and have a child or two or maybe three before 40.
We have done a great job about many things in our society. Empowerment of education for all. My daughter’s in the room. I put as much effort into her education as her brothers. Empowerment in the workforce. It’s incredible what’s happened over the last 50 years. But we’ve been absolutely terrible at something.
Terrible at societies. As parents I’m putting my hand up. Terrible about explaining to young people that as they try to get the best education and training possible, as they try to get established in their careers, that somewhere along the way they also need to find the right person, settle down and start a family.
There are a lot of questions about population. I get it all. I was in a university in Tokyo two weeks ago lecturing to young Japanese students when a British professor came in and heckled me, saying we should not be talking to young people about population at all. Why is it that this topic has become something that we should be guilty of in some context?
No. This topic is destroying us. Destroying us as individuals, as communities, and as nations, oh, and as civilizations too.
Global Population Trends
Let’s go through some questions that I get. But aren’t there too many people in the world? Some of you here today I know are thinking that. Maybe you’re right in a certain context. I’m not here to debate that. But let’s look first at what’s actually happening in the world.
Here it is, our planet. Can it support the people that are here today? That’s not my expertise, but I know this planet isn’t static. This is a moving planet and things are changing very fast. Take India for example. People are worried about population in India. It overtook China recently to become the most populous nation on earth and that worries people. But let’s look at the data.
Births peaked in India nearly 25 years ago. Births are down in India by 20%. India has become an aging country, 32 out of 36 states in India are below 2.0 children per woman. Just like 75% of us live in countries below this replacement level. And no country has ever been known to move the other way.
We use these numbers, birth rates, total fertility rates. They’re obscure numbers, 1.6 sounds like 1.5, like 1.4. But no, these numbers tell us how quickly births are going to half and then half again because this is exponential.
Societal Half-Lives
I like to convert these numbers into what I call societal half-lives. You probably haven’t seen this before, but I think it’s quite simple. If we’re just below replacement level, which is around 2.1 children per woman, births would half every 100 years. One notch lower and that’s down to 300 years. One notch lower again, 150 years.
Well, let’s now look at where we are. Most industrialized nations are somewhere around 1.5, 1.6, births halving, schools halving every 50 years, Japan, China every 40 years, and South Korea, Taiwan, Singapore, Hong Kong, births are halving every 20 years at current rates.
But look how quickly this transformation can happen. 35 years ago, South Korea was at replacement level, 2 children per woman. In 35 years, look what’s happened. I’m going to kind of pause it here because I want to explain for a moment, the only way out of this birth rate crisis is to go back up that curve. And you won’t see a lot of benefit in the early days, going from 1.2 to 1.3 won’t change things a lot, to 1.4, it’s progress. But unless you get back up to 1.8, 1.92, your societies are fading away and that’s mathematical.
Current Consequences
Let’s look now at maybe the current consequences because this is still looking a little bit into the future. If we look at, for example, countries like Italy, one of the countries that worries me most in Europe, today in Italy there are around 1 million people aged 50. Those people will be retiring in around 20 years’ time, who’s going to replace them in the workforce?
Yeah, but economics comes into this, it’s important because our pensions are linked to it, our healthcare systems are linked to it. When they created this chart, there were around 500,000 births in Italy to replace those people in 20 years’ time. Today it’s less than 400,000. This is what I call the birth gap, the gap between the number of people to replace the workers to keep our societies functioning. But this is Italy overall.
What I wanted to show was what’s happening at a much more regional level. With 30 years ago, green areas meant more babies than 50-year-olds. Germany had a problem, Italy too at that time. But look how it’s spread relentlessly across all of Europe.
Three different cultures. But still, in terms of different cultures, Japan at the same time, in the same time period over 30 years, every prefecture in Japan now has what they call a birth gap.
And South Korea, the country I worry about most, has a birth gap of 70%.