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9 Questions on Paul Ehrlich’s Recent Doomsaying

Blog Post | Health & Demographics

9 Questions on Paul Ehrlich’s Recent Doomsaying

If his pessimistic predictions were so wrong in 1968, why does the legacy media still pay him so much attention?

This interview originally appeared in James Pethokoukis’s Faster, Please! newsletter.

Yesterday I offered my thoughts on Paul Ehrlich’s recent 60 Minutes appearance. Today, I offer you Marian Tupy’s. As the editor of HumanProgress and coauthor of Superabundance: The Story of Population Growth, Innovation, and Human Flourishing on an Infinitely Bountiful Planet — check out our podcast conversation about the book here — he’s one of the best people to offer an alternative to Ehrlich’s doom and gloom.

Tupy offered some initial thoughts on Monday in HP, but I wanted to know more. Here are 9 Quick Questions:

1/ I thought Paul Ehrlich’s overpopulation concerns were discredited, yet he recently made a 60 Minutes appearance. How mainstream are his ideas today?

In fact, Ehrlich is pushing two sets of overpopulation concerns. First, he claims that we are running out of resources that we use to create economic value, such as metals, minerals, fuels, etc. Second, he claims that we are running out of nature. As far as I can tell, that includes concerns over biodiversity, ecological sinks, clean air, as well as abundance of cropland, grazing land, fishing grounds, forests, etc. Basically, he believes that we are raping and poisoning the planet. The first set of concerns is no longer widely held among mainstream economists (if it ever was) but remains popular among non-economists, especially biologists, and among the larger public. The second is taken more seriously by all kinds of scholars as well as the public.

2/ You note that CBS chose not to feature Paul Romer, Larry Summers, or any number of scholars who could counter Ehrlich’s overpopulation claims. Why do you think the media is so committed to that narrative?

Alex Epstein, whose book Fossil Future I recommend, notes the persistence of so-called “designated experts” that the media goes to for opinion on certain subjects regardless of whether those experts were correct in the past. So, Ehrlich is the “resources” expert, John Brennan is the “intelligence” expert, Bill Kristol is the “foreign policy” expert, and so on. (The last two are my examples, not Epstein’s.) It helps if these “designated experts” say things that the various media outfits and their audiences already believe in. So, I think that media bias and market segmentation play a role. But that’s not all. Environmental catastrophe is a great subject. When you sell the apocalypse, the audience feels like you are deep and that you care. When you discuss rational optimism or “solutionism,” it feels like you are being glib and uncaring.

3/ 60 Minutes does note that The Population Bomb’s predictions were wrong: “The alarm Ehrlich sounded in ’68 warned that overpopulation would trigger widespread famine. He was wrong about that. The green revolution fed the world.” What would you add to CBS’s disclaimer?

The Green Revolution (i.e., the transfer of agricultural technology and best practices from rich nations to poor ones in the post-WWII era) was important, but there were many other technological and scientific breakthroughs or innovations that allow us to produce enough food to feed 8 billion people (and, potentially, many more). Today, we can grow rice in saltwater and hydroponic lettuce underground. So, productivity gain is ongoing. It did not stop with the Green Revolution. Let’s not forget political and economic changes. The collapse of communism, economic liberalization, and globalization helped. India now exports food and so does Ukraine (or at least it did, before the Russian invasion). Simply put, the world has more people who are freer and more connected than they were in the 1960s. They are cooperating to solve our problems.

4/ The argument against overpopulation centers on technology and human ingenuity, but isn’t it possible we’ll run out of ideas and Ehrlich will be proven right in the long run?

In our book Superabundance, we claim that abundance depends on people and freedom. When the world’s population starts falling (around 2060 or so), we will have fewer brains to come up with new ideas. We could compensate for that decline with advances in AI and increasing human freedom (i.e., there are huge chunks of the world where people are not allowed to flourish and participate fully in the global economy). If freedom shrinks (as has been the case in recent years), AI fails to materialize, and human population declines, we could have a less prosperous future.

5/ You write, “Economic development, in other words, is the key to environmental protection.” What do you mean by that?

Clean environment is a “luxury good.” Poor people care less about the environment than rich people—generally speaking. The former have more pressing problems than the latter—as shown by global environmental quality rankings, such as the Yale Environmental Performance Index. When poor countries develop (like Chile and South Korea have done, to give just two examples), they will be able to have more resources to protect the wildlife; they will be able to afford to put in place and enforce more stringent environmental regulations; they will urbanize, and thus get off the land; their energy sources will be cleaner (e.g., gas instead of wood); and their agriculture will be more productive, thus yielding more food from fewer acres of land. Nature will rebound, as it always does.

6/ You advocate “a balance between environmental concerns and human flourishing—understanding that humans are not only destroyers, but also creators and protectors of the planet and that which thrives on it.” What does that balance look like in practice?

There is no universal standard. As I noted in the previous answer, much depends on your level of economic development. If you are starving, like Zimbabweans did when I visited that country in 2008, wild animals will be seen as food rather than a tourist attraction. In hard times, human survival trumps other considerations. In Switzerland, in contrast, people prioritize environmental quality and are willing to put up with all sorts of daily inconveniences to achieve that goal. I will add this: In the last few decades, a certain segment of the environmental movement in the West has seemingly lost sight of human well-being and seems to prioritize relatively unimportant environmental concerns over human flourishing. We need the pendulum to swing back toward the center.

7/ You write, “The reason the planet matters is that we are here to perceive it and to enjoy it with our senses. (Animals don’t care about biodiversity per se. What they do care about is finding an organism to kill and eat or mate with.)” Is the protection of the natural environment and endangered species not a good in itself? Must conservation efforts be subordinated to human desires?

I am a humanist and thus guilty of anthropocentrism. We all have our own hierarchy of values. That’s mine. But I also think that mine is a logically defensible position. Without humans, what exactly is the point of the planet? Who cares whether it exists or not? Only we care. I thought that was a point worth making, given that, increasingly, progressive media outlets, like the New York Times and The Atlantic, are giving space to misanthropes who argue in favor of zero births, end of humanity, etc. Finally, I do think that a humanist position is compatible with a healthy planet. I love nature. It makes me happy. And, from what I learned during the COVID-19 lockdown, the same is true of most people. Healthy planet and human flourishing are inseparable.

8/ On 60 Minutes, Ehrlich says, “Humanity is not sustainable. To maintain our lifestyle (yours and mine, basically) for the entire planet, you’d need five more Earths.” Where does such a figure come from, and why do you think it’s flawed?

It comes from an NGO called the Global Footprint Network, and it is fundamentally mistaken. As we argue in Superabundance, people need to stop thinking in terms of atoms and start thinking in terms of knowledge. The number of atoms on the planet is finite, but the value we can get from those atoms is potentially infinite. When people first started to convert sand into glass, they turned glass into beads and jars. Today, we use glass in microchips and fiber-optic cables. Instead of radios, TVs, cameras, maps, and clunky rotary phones, we have iPhones. Instead of cutting down forests to print Encyclopedia Britannica, we have Wikipedia. We dematerialize, and we miniaturize. So new knowledge can allow us to become unimaginably wealthy on one planet.

9/ The World Wildlife Fund finds that “monitored populations of vertebrates … have seen a devastating 69 percent drop on average since 1970.” Is Ehrlich wrong to suggest that “humanity is very busily sitting on a limb that we’re sawing off” by causing biodiversity to decline?

I cannot do better than Ronald Bailey, who understands that subject area much better than I do. But, in a nutshell, the situation is much less scary, and human impact on biodiversity seems to be greatly exaggerated by the usual suspects. Let me simply say that never before in human history have we had as much wealth, as skilled of a workforce capable of solving problems, and such determination to ensure that the biosphere is protected and extinction rates minimized. Heck, we are even seriously discussing bringing species back from extinction. One of the keys to continued human and ecological progress is to get people off the land and into the cities. Nature will take care of the rest.

Blog Post | Population Growth

No, Prosperity Doesn’t Cause Population Collapse

Wealth doesn’t have to mean demographic decline.

Summary: For decades, experts assumed that rising prosperity inevitably led to falling birth rates, fueling concerns about population collapse in wealthy societies. But new data show that this link is weakening or even reversing, with many high-income countries now seeing higher fertility than some middle-income nations. As research reveals that wealth and fertility can rise together, policymakers have an opportunity to rethink outdated assumptions about tradeoffs between prosperity and demographic decline.


For years, it was treated as a demographic law: as countries grow wealthier, they have fewer children. Prosperity, it was believed, inevitably drove birth rates down. This assumption shaped countless forecasts about the future of the global population.

And in many wealthy countries, such as South Korea and Italy, very low fertility rates persist. But a growing body of research is challenging the idea that rising prosperity always suppresses fertility.

University of Pennsylvania economist Jesús Fernández-Villaverde recently observed that middle-income countries are now experiencing lower total fertility rates than many advanced economies ever have. His latest work shows that Thailand and Colombia each have fertility rates around 1.0 births per woman, which is even lower than rates in well-known low-fertility advanced economies such as Japan, Spain and Italy.

“My conjecture is that by 2060 or so, we might see rich economies as a group with higher [total fertility rates] than emerging economies,” Fernández-Villaverde predicts.

This changing relationship between prosperity and fertility is already apparent in Europe. For many years, wealthier European countries tended to have lower birth rates than poorer ones. That pattern weakened around 2017, and by 2021 it had flipped.

This change fits a broader historical pattern. Before the Industrial Revolution, wealthier families generally had more children. The idea that prosperity leads to smaller families is a modern development. Now, in many advanced economies, that trend is weakening or reversing. The way that prosperity influences fertility is changing yet again. Wealth and family size are no longer pulling in opposite directions.

This shift also calls into question long-standing assumptions about women’s income and fertility. For years, many economists thought that higher salaries discouraged women from having children by raising the opportunity cost of taking time off work. That no longer seems to hold in many countries.

In several high-income nations, rising female earnings are now associated with higher fertility. Studies in Italy and the Netherlands show that couples where both partners earn well are more likely to have children, while low-income couples are the least likely to do so. Similar findings have emerged from Sweden as well. In Norway, too, higher-earning women now tend to have more babies.

This trend is not limited to Europe. In the United States, richer families are also beginning to have more babies than poorer ones, reversing patterns observed in previous decades. A study of seven countries — including the United States, the United Kingdom, Germany and Australia — found that in every case, higher incomes for both men and women increased the chances of having a child.

This growing body of evidence challenges the assumption that prosperity causes people to have fewer children. 

Still, birth rates are falling across much of the world, with many countries now below replacement level. While this trend raises serious concerns, such as the risk of an aging and less innovative population and widening gaps in public pension solvency, it is heartening that it is not driven by prosperity itself. Wealth does not automatically lead to fewer children, and theories blaming consumerism or rising living standards no longer hold up.

Although the recent shift in the relationship between prosperity and fertility is welcome, it is not yet enough to raise fertility to the replacement rate of around 2.1 children per woman — a challenging threshold to reach.

But the growing number of policymakers around the world concerned about falling fertility can consider many simple, freedom-enhancing reforms that lower barriers to raising a family, including reforms to education, housing and childcare. Still, it’s important to challenge the common assumption that prosperity inevitably leads to lower birth rates: Wealth does not always mean fewer children.

This article was published at The Hill on 6/16/2025.

Blog Post | Food Production

More People, More Food: Why Ehrlich and Thanos Got It Wrong

Compared to 1900, we have 8.28 million fewer farmers today with 263.7 million more people. And we live 30 years longer.

In 1900, the U.S. Census recorded a total population of 76.3 million, including 11 million farmers. Today, with a population nearing 340 million, the number of farmers has dropped to just 2.72 million.

At the turn of the century, each farmer fed 6.94 people. Today, that number has risen to 125. While the U.S. population grew by 346 percent, farmer productivity soared by 1,702 percent. Each one percent increase in population corresponded to a 4.92 percent increase in farmer productivity.

In 1900, life expectancy was just 47 years. Today, it’s around 77. Medicine and sanitation played a role, but the abundance of food made possible by farmers discovering and applying new knowledge was a foundational driver of that gain.

So, who’s going to tell Ehrlich and Thanos they had it backwards? More life discovers more knowledge, which leads to better tools and more abundant resources.

Find more of Gale’s work at his Substack, Gale Winds.

Blog Post | Population Growth

Promoting Parenthood in a Free Society | Podcast Highlights

Stephanie Murray joins Chelsea Follett to discuss discourse around falling birth rates, the tension between pro-natalism and classical liberal values, and how it might be resolved.

Listen to the podcast or read the full transcript here.

In many places, fertility rates are hitting record lows. Practically all rich countries and many developing countries are now below the replacement fertility rate. Some countries are already seeing their populations age and decline, and if this continues for long enough, the global population will begin to shrink.

Your piece discusses an aspect of this topic that I find really interesting. So, let’s walk through it. You begin with an anecdote about how, a little over a year ago, you were conducting an interview about the possible causes of fertility decline. Tell me what happened.

I write on this topic with some frequency, and I follow research on it very closely, so I often interview people who research fertility, economists, sociologists, demographers, and so on. And so I was interviewing somebody, a demographer, about a certain cause of fertility decline. At one point in the interview, she kind of stopped and wanted to clarify that the issue here is that people are having fewer kids than they want. She wanted to make it clear that she wasn’t saying we should raise the birth rate for any kind of national interest.

My piece pushes back on that way of thinking.

Why do you think people tend to characterize the falling birth rate issue this way?

I think there’s a sense that catastrophizing low fertility could justify taking really drastic and coercive steps. And I think that is a major and legitimate concern. Getting the state involved in getting people to have children or stop having children could be a legitimate threat to civil liberties.

People also sometimes acknowledge that falling fertility is a problem, but they redefine it. They’ll say something like, “There are going to be economic challenges because of low fertility, but the problem is with our economic system, so let’s just change the economic system.”

I am sympathetic to people who want to talk about economic reforms, especially if pension systems, for example, are unsustainable. But as you say, there is no reason you can’t discuss both of those things.

There are definitely ways that we can adapt our economic system to low fertility, but there are limitations to that approach. You get this sense that people think that the need for children is just a byproduct of capitalism, and if we just changed our economic system, then we wouldn’t need endless growth propped up by a high birth rate. Maybe we can tweak our pension system, or become less reliant on GDP growth, but it’s a fact of human existence that you need new people to take over as the rest of us get older.

Now, some demographers and economists push back on the idea that anything below replacement-level fertility is going to cause massive issues. Some think that we could have anything above 1.5 births per woman, and with immigration, technological advancement, and education, we’ll be fine. One demographer that I spoke to said that since we are becoming more productive per capita as time goes on, each generation has “broader shoulders,” to stand on. So, maybe we can do more or as much as we are currently doing with fewer people.

That said, you can’t have a society without kids. We don’t know exactly when the falling birth rate becomes a big problem or how long we have before it’s a big problem. Lots of room for disagreement there. But eventually, it becomes a problem.

Let’s talk about some of the reasons that people are choosing to have fewer children. You make a very good point that in the past, parents captured more of the fruits of their children’s labor, while today, most of us are raising kids who will spend most of their lives working for someone else.

Yeah, for a lot of human history, parents were employers who grew their own laborers. There were steep economic incentives to raise kids. It could be brutal on a personal level. If you couldn’t bear children, your husband might put you aside and find somebody else who can. Today, parents still do a lot of the work of raising children, but they’re raising kids who are going to work for somebody else.

Of course, there are still practical reasons to have children. Basically everywhere in the world, lots of elder care is done informally by family members, especially adult children. However, even still, that care is not reliable in a liberal society. This is how liberalism works: when you grow up, nobody can tell you what to do, including your parents. So, I think capitalism, labor markets, and liberal values in general have altered the relationship between parents and children in a way that fundamentally changes the economics of child-rearing.

I do think it is easy to oversell the importance of economic considerations and downplay the psychological or cultural factors. It’s notable that, to date, no amount of government spending anywhere in the world has successfully restored sub-replacement birth rates to replacement levels.

You spend a lot of your piece talking about another factor in people’s decisions about having children: the feeling that having children is good for your society’s future. Could you tell me a bit about that?

People often pitch parenthood as simply an experience that makes the parents feel good without acknowledging the important role parents play in society.

I think that undermines the case for parenthood. If we pretend that parenthood is just about you being happy, we rob parents of a source of satisfaction. Imagine if we tried to recruit people to the army by saying, “It doesn’t really matter how many people sign up. This is about you getting the experience of holding a gun and riding in a tank.” I really don’t think anybody would join. People are motivated to serve their communities. So why are we downplaying that? Why are we so scared of saying, “you should consider having kids because we need parents”?

How do you think that relates to this view that the world is overpopulated and having kids is essentially selfish? Do you think that kind of messaging might affect people’s decision-making?

Absolutely.

A couple of years ago, I signed up for this half-marathon hike and ended up hiking it with this woman who was a total stranger, and we were talking about fertility rates. You can’t go on a half-marathon hike with me without me talking about fertility; that’s pretty much inevitable.

So, we were chatting, and she, at one point, said that she felt like she was harming the planet by having kids, and since she had to take maternity leave, she was also slowing down work. She felt like she was doing a selfish thing and drawing resources away from the planet and from her workplace in order for her to have the experience of parenthood.

If that is how you view parenthood, it becomes a lot harder to justify the decision. And if you already have personal reservations like, “would I be a good mother?”, it could easily tip the scales toward not having children.

This topic is very tricky for those of us who are devoted to a free society. I really love the last paragraph of your piece. You say:

Those of us who want to reverse falling fertility while preserving the values of a liberal society have a tricky task ahead. We’ve got to hold two truths at once: that no one ought to be coerced into parenthood, and that we will all suffer if no one raises kids. That may seem like an impossible line to walk—and yet, we walk versions of it all the time. I don’t think there’s anyone in the world that would hesitate to admit that we need doctors. And yet, most of us agree no one should be coerced into medical school. In other words, acknowledging the necessity of parents while respecting individuals’ right not to become one is really just a matter of applying the same logic to parenting that we do to every other path in life.

Could you expound on that?

I think most people can agree that we don’t want people to be coerced into parenthood, but we can’t allow that concern to make us overlook the fact that we need parents. They provide an essential service in society. So we have to be willing to hold both of them at the same time. I think people just have this impulse that that’s not possible, but we do this all the time with other types of work.

If we go with the military example, most people think that national security is important, but most people also oppose conscription. They want a volunteer army. It’s the same with basically any line of work. We don’t like forcing people to do things, but that doesn’t stop us from acknowledging that society can’t function without doctors or teachers.

You’re basically just suggesting that people voluntarily give more social recognition to parents. And you write that all around you, you can see that parents, and mothers in particular, are desperate for recognition that the work they are undertaking is valuable for the world. Do you think that more social recognition could shift the culture toward higher birth rates?

I do. I’ve always thought that parenthood is really important, but I constantly felt like the culture was telling me otherwise. There is this assumption that you shouldn’t get married and have kids right after college, right? That you should do something with your life. But having kids is doing something. And there are lots of ways that we denigrate parenthood and treat it as a waste of somebody’s skills and talents.

If we thought more about the work of parenthood in the way that we think about other work, if we treated it like a really cool way of contributing to society, maybe people would be more motivated to go into that line of work.

If you look at the few populations in wealthy countries that do have high birth rates, religious communities, for example, those populations give people a lot of positive messaging about how raising children is a good thing for society.

I just remembered that the woman I went on that half marathon hike with, who seemed to believe she had done a selfish thing by having children, told me about a time she visited Jordan. She was so struck by what it was like to have a child there. In the UK, where I live, sometimes when you go into a coffee shop, people almost groan if they see you brought your kids. But in Jordan, she said that when she would walk into a coffee shop or a restaurant, it felt like she had gifted them this child. She felt an overwhelming sense that people were delighted that she had this child there, and she didn’t even live in Jordan. I think this kind of social recognition changes how you think about having children.

Another other thing to remember about social recognition is that it’s free. It doesn’t cost taxpayers a single dime, and there’s not really any downside to people just voluntarily giving this kind of recognition to the parents in their lives.

One of the reasons that people are hesitant to talk about birth rates is that, as you wrote in your piece, it can feel icky to have a strong opinion on such a personal decision. You don’t want to try to make everyone follow the same path and become a parent.

I think we need to use other types of work as a model for how we think about parenthood. There are a lot of roles that need to be filled in society, and just because you are not filling all of them doesn’t mean that you’re failing society. You can appreciate the existence of doctors and nurses without feeling bad that you are not a healthcare worker.

We usually end this podcast with an optimistic note. What trends, if any, make you feel optimistic about the future of birth rates?

I think that people are becoming more receptive to the idea that parenthood, motherhood, and caregiving are valuable and often overlooked. It feels like we’re on the cusp of being willing to admit that we need parents. Not in a catastrophizing way, but in a “hey, this is important” way. So, I think we’re moving in the right direction.

The Human Progress Podcast | Ep. 60

Stephanie Murray: Promoting Parenthood in a Free Society

Stephanie Murray joins Chelsea Follett to discuss discourse around falling birth rates, the tension between pro-natalism and classical liberal values, and how it might be resolved.