Overpopulation has been linked to societal problems such as unemployment, poverty, resource depletion, strain on infrastructure, and social and economic inequality.
But in a guest lecture at the Marriner S. Eccles Institute for Economics and Quantitative Analysis, Michael Geruso made a compelling case for depopulation now posing a far more significant threat to the planet’s future.
Geruso, an economic demographer, public economist, and associate professor of economics at the University of Texas at Austin, is the co-author of the book, “After the Spike: Population, Progress, and the Case for People,” the subject matter of which was presented to Eccles School students on Nov. 19.
He noted that Earth’s population first reached 1 billion around 1800, and 2 billion around 1925. A century later, the worldwide population is presently around 8 billion and is trending toward a peak of around 10 billion over the next few decades. This exponential growth has been attributed to progress in hygiene, crop management, medical interventions, et cetera collectively enabling more children to live to adulthood.
Recently, however, there’s been considerable news about declining birth rates. Turns out, it’s hardly a new phenomenon — they’ve been trending that way for centuries. Neither is it merely a U.S. phenomenon, as two-thirds of people in the world live in a country with birth rates below two children per two adults.
Why does this matter?
Once global birth rates fall below 2.0, unless they later rise and permanently remain higher, each generation will be smaller than the last. That is depopulation. And it will lead to rapid and significant change.
For example, consider a birth rate of about 1.5 (like, say, in the U.S. and Europe): A first-generation population of 100 would lead to a second-generation population of 75, which would lead to a third-generation population of 55. If we take a birth rate of 1.0 (as in China or Puerto Rico), a first-generation population of 100 becomes a second-generation population of 50, which becomes a third-generation population of 25.
More simply, if birth rates around the world converge towards an average of 1.6 kids per 2 adults, as Geruso and his co-author theorize, the global population will fall by two-thirds each century.
The overcrowding, resource depletion, and so on notwithstanding, such a decline would not be a positive development.
The consequences would be considerable. As Geruso points out, none of us exists in a vacuum; the good lives we live are built on the progress others have caused, and progress doesn’t happen automatically as time marches forward — people have to achieve it.
Those gains in crop management and medical interventions might not exist if populations and cultures didn’t grow, and the knowledge and resources that enable them to continue might cease to exist if depopulation occurs.
“We live better lives — less precarious, more educated, healthier, safer — than in the past not because we have more grit, or intelligence, or moral integrity,” Geruso pointed out. “It’s because we enjoy the progress others have made. We should hope for that progress to continue.”
Birth-rate and population stabilization are needed. And indeed, some nations have taken note. The problem, for now, is that governments, societies, cultures (and researchers, for that matter) don’t presently know how to bring birth rates back up to 2.0.
There have been some measures enacted to counteract the decline. Sweden, for example, offers a year of parental leave, free childcare, and free college, thus removing some of barriers assumed to stop people from having children. So far, though, none of these interventions have worked as intended. They may lead to people having a child earlier, but still having only one.
Geruso likened the situation to that of climate change, noting that even if there’s some general degree of awareness, until the issue becomes part of the cultural zeitgeist and recognition of the potential consequences takes hold, meaningful progress will be lacking. To that end, he encouraged students to go out and have conversations about this topic and raise general awareness of how our individual choices can have long-term effects.