Au Naturel
Au Naturel
Good grief. This is all quite mainstream.I know the most likely cause(s). It's not a secret. Just unlikely to enter mainstream discourse yet.
The population decline was inevitable. No conspiracy is needed. Science removes the need for God in the equation. That eliminates the religious injunction to have children. The arguments against birth control and early-term abortion were always religious. Religiosity in advanced economies has slowly but steadily declined for the last 70 years. That includes the US.
Feminism makes marriage less important and offers women lifestyle choices other than childrearing. Childless women become role models.
Technology created the birth control pill. It became extremely easy to avoid pregnancy and put the control in the hands of the woman, who (usually) cares more about such things than the man.
The economics of industrial and post-industrial life turn children from assets to support the family into liabilities who leave home as soon as they become economically viable. Since children are now optional, only people with a deep need to raise children will have them.
China shot itself in the foot with the one-child policy. But now that it is revoked, the people of China decided that only having one - or no - child is a pretty good thing. Birth rates have not rebounded. China is just beginning to implode.
The result is that technologically advanced countries simply don't have children like they used to. Unless you really LOVE children, there's nothing to be gained from it. Many countries in Europe and East Asia are looking at substantial depopulation in the next few decades. OTOH, parts of Africa are exploding. I don't believe current rates will continue. If they do, then Nigeria will have more people by the end of the century than China does now.
Much of the globe will suffer from not having enough young worker bees to support the elderly. The economic survival of nations will depend on further automation and AI to replace the workers who weren't born.
Eventually, it will stabilize. Not every sector of the population will experience the same drop. People who want more children will grow to become a larger part of the population.