Elon Musk and Paul Ehrlich…
Only a minority of people know who Ehrlich was; fewer still would know why I mention the two men together. But they represent diametrically opposed perspectives on a major issue: population growth.
Billionaire tech mogul Musk has made news in recent years warning that our below-replacement-level fertility rates are a threat. “If people don’t have more children, civilization is going to crumble,” he has stated. “Mark my words.”
Ehrlich, an entomologist by training who passed away March 13 at 93, also had made news. Author of the once-(in)famous 1968 book The Population Bomb, he warned that overpopulation and scarcity would cause civilization to crumble. He once predicted the U.S. population would by 1999 have declined due to starvation — down to 22.6 million people. (Now Florida alone has about that many.) Then there was his prognostication about our friends across the pond. “If I were a gambler,” he’d stated, “I would take even money that England will not exist in the year 2000.”
Now, Ehrlich might’ve made a correct prediction, too, though I’m not aware of one. Yet despite his chronic errancy, a new YouGov study finds that more Americans lean toward his perspective than Musk’s. This is even though the vast majority of countries — approximately 136 — have birthrates below replacement level (2.1 children per woman). It’s even though demographers inform that the world’s population will begin declining by our century’s end.
The New Study
This discussion must begin with the acknowledgment that we may not even know what the world’s population is. It’s generally believed to be about 8.3 billion. Yet 2025 research held that we might be under-counting man’s numbers in rural areas by literally billions.
As for the new study on what population notions populate Americans’ minds, YouGov reported Wednesday:
Ehrlich’s core argument — that overpopulation is a big problem that needs to be addressed — is more widely known than Ehrlich himself (and often associated with English economist Thomas Malthus). Americans are more likely to say overpopulation is a problem than they are to say low birth rates are. This is true when Americans are asked about the U.S.: 47% say overpopulation in the U.S. is a very or somewhat serious problem and 41% say low birth rates are. And it’s especially true when Americans are asked about the world as a whole: 62% say overpopulation is a big problem globally and 37% say low birth rates are.
Liberals are more likely than conservatives to say overpopulation is a problem, and less likely to say low birth rates are. But even conservatives are more likely to say overpopulation is a serious problem worldwide than to say low birth rates are.
In fact, conservatives were the only group surveyed that identified low fertility rates as a bigger problem in the U.S. than overpopulation. Fifty-seven percent of them took this position, just 42 percent the opposing one. The other polled groups — “U.S. adult citizens,” “Liberals,” and “Moderates” — all called overpopulation a greater problem.
In reality, however, states YouGov, “Birth rates are declining in the U.S. and worldwide.” The site then continues:
A majority of Americans say the number of children being born is falling in the U.S. (56%, while 16% say it’s increasing). Americans are more closely divided over whether birth rates are declining worldwide (36% say they are, and 27% say they’re increasing). 29% of Americans incorrectly say the number of children being born in India, the world’s most populous country, is increasing, and only 12% correctly say it’s decreasing.
As is apparent, Americans’ knowledge on this matter is a mixed bag. Yet since a strong plurality (47 percent) of our citizens believe overpopulation in America is a problem, they should ponder a question.
That is, “Do I believe in halting all immigration?”
After all, the U.S.’s fertility rate is now only ~1.6, well below replacement level. And beginning in 2030, immigration will be the only cause of population growth. It’s already the major cause.
(For the moment, however, births in the U.S. still outpace deaths.)
Of course, though, we have to wonder: How many Americans even know this?
Why Should I Care?
Yet many may ask: Even if man’s numbers are dropping, why should we fret? I addressed this back in 2008 while reviewing the fine documentary Demographic Winter. As I wrote:
First, rendering demographic-based economic forecasting, [analyst] Harry S. Dent tells us that when the enormous baby-boom generation moves beyond its peak spending years — which end at age 48 — its reduced spending will cause an economic contraction, one the smaller generation following it will not be able to forestall. We will then follow in the footsteps of Japan, which had no baby boom, grayed before us, and experienced an economic meltdown in the 1990s (which Dent predicted). During this period, the Nikkei stock exchange lost 80 percent of its value, real estate depreciated with it, and Japan has wallowed in continual recession ever since. Of course, a major non-demographic factor falling outside the scope of this film — Japan’s stifling corporate socialism — was also at play. Nevertheless, the film makes a compelling case that aging populations have a huge negative impact on the economy, whether in Japan or elsewhere.
In our own country, our baby boomers will begin crossing the threshold into retirement in 2010. Yet that is just the tip of our demographic winter iceberg. As the old increase in number relative to the young, there will be fewer workers to drive the economy and fund Social Security and Medicare. As a result, the latter may be taxed more heavily and, in turn, work less and have even fewer children, creating a vicious circle. Also, most innovators are between 30 and 44 years of age; thus, innovation will decrease commensurate with the decline of that group. Moreover, with the reduction in overall consumer spending, companies will have less incentive to fund innovation. [Late economist] Gary S. Becker sums up the effects well by paraphrasing Adam Smith: “Depressions are associated with decreasing population.” Was Adam Smith correct? History both before and after his time instructs that he was.
This is true, too. Yet Dent’s predictions did not come to pass in the time frame he laid out. Moreover, much has changed since a generation ago. Specifically, there are warnings that artificial intelligence (AI) and advanced robotics will ultimately displace most workers. Why, Elon Musk himself has predicted that work will be optional for humans within 20 years. Of course, we still might need human innovators. But why would vast numbers of human worker bees be required to power an economy if AI robotic slaves performed all the labor? Will this technology change the equation?
It would be interesting hearing how Musk reconciles his fecundity clarion call with his prediction that tech will, at least largely, render humans economically obsolete.
All this said, the possibilities outlined above are based on certain assumptions about the future. (E.g., that we won’t destroy ourselves.) But assumption is just that, and it’s why we have to be humble about our prognostications. After all, Paul Ehrlich is not the only intelligent person whose predictions have become laugh lines.
For those interested, the Demographic Winter documentary is below.
And what follows are some perspectives on AI and robotics displacing workers.
