IDK, there are a couple billion people in the world whose economic contributions are near nothing because:
- their countries failed to properly educate them,
- their cultures are incompatible with economic success*,
- they are crammed into places with insufficient resources which leads to expenditure of energy competing with others,
- they are paying massive congestion costs to live in the world's slums, without access to clean water, electricity, communications, or transportation.
Seen through this lens, the process of economic growth amid declining populations comes down to changing the circumstances of billions of people so that they can become productive. A slum containing a million people might have a lower economic output than a hundred thousand educated workers living in high rise apartments.
The rise of China was not driven by population growth; it was driven by a choice to do things differently. Had the urban workers who fueled China's economic explosion instead stayed as peasant subsistence farmers, China would matter to the world economy about as much as it did in the early 1970s. Similarly, the economic dominance of the U.S. in the late 20th century was not due to being more populous than other areas. Instead, it had something to do with how the people had organized themselves, established values, educated their children, and became more productive than people anywhere else.
Also seen through this lens, the problem to be concerned about is the risk that cultures fail to evolve in a more productive direction. Even as the cultures in China, India, Africa, the Middle East, and Latin America have become more capitalistic, consumeristic, and scientifically literate, we are seeing troubling trends toward an Anti-enlightenment in the Anglosphere and Euro space, with a growing tolerance for corruption and authoritarianism among these former leaders in the shift toward productivity. It seems the West has lost its ability to muster an immune response against anti-productive or backward cultural memes. The rise of the internet has created decay in the cultural institutions that once led to prosperity, like public health, education, universities, and governance.
*For example: Strict gender roles that reduce women to the level of cattle, hyper-religiosity leading to an anti-educational and anti-science biases, low openness to new experiences, high tolerance for corruption, nostalgia for the traditional ways, racism, superstition, and scapegoating of foreign others.
