The Population Crash

The demographic Titanic is going to hit the iceberg. We may be thankful that some people on the ship are building lifeboats while there is still time.

In 1968, Stanford biologist Paul Ehrlich published The Population Bomb, a book extrapolating global population growth data to predict a catastrophe as humanity’s demand for resources outstripped supply. The book became a bestseller and catapulted Ehrlich to worldwide fame. But today, just over a half-century later, humanity faces a different challenge. We are in the early stages of a population crash.

Ehrlich’s basic math wasn’t necessarily flawed. In 1968, the world population was 3.5 billion, and today the total number of humans has more than doubled to just over 8 billion. Anyone with a basic understanding of exponential growth can appreciate that if human population doubles every 50 years, within only a few millennia, an unchecked ball of human flesh would be expanding in all directions into the universe at the speed of light. Which means, at some point, Malthusian checks will apply.

But where extrapolation yielded panic, reality has delivered something completely different. Today population growth is leveling off almost everywhere on earth, and the cause of that decline started, ironically, back in the 1960s when Ehrlich wrote his book. The reasons for this are subtle, because the only ultimate determinant of population growth is the average number of children a generation of women are having, and the impact of that and other variables take decades to play out.

In the late 1960s, the United States, along with most Western nations, had just moved out of its baby boom years, that period from 1946 through 1964, when women were still having lots of babies. Having grown up during the Great Depression, followed by a world war, the choice to have large families may have been a response to the adversity these women and men experienced as they came of age. That theory is borne out by subsequent history.

Over the past 50 years, in a pattern that has been repeated around the world, as prosperity increased, the average number of children per woman of childbearing age has decreased. The chart below provides hard evidence of this correlation. Tracking data per nation, the vertical axis is the average number of children per woman. The horizontal axis is the median income. A clear pattern emerges. In extremely poor nations, birth rates remain at Ehrlichesque levels. But once a nation’s median income rises barely above poverty, at around $5,000 per year, the average number of children per woman drops below replacement level.

One may view this chart and conclude that if an average of 2.1 children per woman is necessary to keep a population stable, this cluster of nations averaging around 1.5 children per woman can’t be that bad. But that reasoning ignores basic math. At a replacement rate of 1.5 per woman, for every 1 million people of childbearing age living in a nation today, there will only be 420,000 great-grandchildren. This means that nation’s population will drop to 42 percent of what it is today in less than a century. And the numbers get worse very fast.

South Korea’s current fertility per woman, for example, is a dismal 0.81, and those are extinction-level numbers. At that rate of reproduction, for every 1 million Koreans of childbearing age today, there will only be 66,000 great-grandchildren. South Korea is on track to disappear in less than a century.

This collapse is just now becoming apparent in overall population numbers because it is only when a numerically superior older generation, the product of fecundity, begins to die that absolute totals begin to drop. As baby boomers, known to demographers as the “pig in the python,” reach the end of their lifespans, the consequences of the decade decline in birth rates will finally be reflected in dramatic downward shifts in total population. That process is...

Read More HERE