A common logical error is to explain general phenomena by pointing to problems that affect only particular cases. If a chemical behaves the same way in experiments conducted at every institute, the cause cannot be that one institute has contaminated test tubes, another heats the substance to too high a temperature, and a third keeps it under excessive pressure. The cause must be something present in all of those institutes: either a property of the substance itself or a procedure used everywhere.
With chemicals, this is obvious. Yet when it comes to social phenomena, we often make the same mistake without giving it a second thought. If birth rates are falling sharply around the world, the cause cannot be that there is a housing shortage in Czechia, that people are being vaccinated in Poland, that people work too much in Korea, that China once had a one-child policy, that Mexico has drug gangs, that Iran has a religious government, and that Russians drink too much vodka. We need to look for a force at work in all these countries and everywhere else—in every culture, civilization, and economic system.
That is why studies examining fertility on a global scale are so valuable. One such study, published in August under the title The Economics of a Shrinking World, was written by a group of American economists. Its main findings can be summarized as follows:
- Birth rates are falling everywhere. Even in sub-Saharan Africa, the average has declined within a single generation from five to seven children per woman to three or four. That still means enormous population growth, but these countries are clearly following the same trend as the rest of the world, only with some delay.
- Birth rates are falling fastest in poor countries such as Mexico, Thailand, Colombia, Tunisia, and Iran. For most of the past two hundred years, people in poor countries tended to have more children. Today, the reverse is true.
- The era in which the poor had more children than the rich has also come to an end. Across most of the world, the poorer the social group, the fewer children it has. The main exception is in places with generous benefits, where some of the very poor have children in order to receive them.
- The study’s authors stress the distinction between a cause and a factor that accelerates a trend. Take the shortage of housing. If people truly wanted children, they would find a way—by moving to the countryside, living with their parents, or doing something else. But when they are reluctant to have children and already hesitating, the lack of affordable housing can tip the balance.
- There were signs of a looming collapse in birth rates as early as the 1980s. But international conferences and the global media were consumed by the overpopulation hysteria—which had been wholly fabricated from the outset—leaving no room for a serious examination of the issue.
- Birth rates are not falling to zero; they are settling at a new, lower level. In Italy, for example, the birth rate has remained at roughly 1.15 children per woman for twenty years.
One small additional point. As the authors rightly observe, fertility has a peculiar feature: a very small change in human behavior can produce enormous statistical effects. If just one woman in four has one fewer child, the overall birth rate falls from a respectable 1.8 to a supposedly—or actually—catastrophic 1.3.
In light of these findings, it is becoming increasingly clear that neither large-scale government programs to encourage childbirth nor more affordable housing can reverse the trend. I, too, was overly optimistic about that. Such measures can slow the decline, however, and that may be enough to give a national society time to adapt. What, then, is the global cause? In recent years, many hypotheses have been discussed, but none has held up.