World population might peak by mid-century and return to around current size by 2100 - Dr Darrell Bricker
He guesses 2040's will be the beginning of population decline, with the last of the boomers. 2030's will be a largescale retirement.
We thought the pandemic would lead to a baby boom. Instead, fertility rates depressed. Counties that depend on migration for population also have growth disrupted as travel was more difficult.
China, the world's largest country with 1.4b people, is projected to lose almost half its population size this century. India, which has 1.4 also, will lose 290m in the century. USA with 330m will rise about 11m.
Urbanization has a major affect on fertility, and therefore on population. On the farm children are extra hands; in the city they're more expense. We'll have an older, less fertile population.
Almost 60% of people live in cities, and that will be around 70% by 2050. This will be moreso in Asia and Africa (China will be 80% urban, it's presumed; Japan is currently 92% urban and might go to 95%). Less in North America and Europe (already quite urbanized).
The changing role of women is a major factor. Women are the majority of university students in the first world (most countries), and so delay marriage or children till their late 20s or early 30s. It's said that the best thing to look at to guess a country's fertility rate, it's the education rate of women.
Societies don't value large families nowadays either.
The fertility rate in 1960 was 5.2, and it's 2.3 or 2.4 now. Expected to be 2.2 in 2050. Japan is 1.4 right now. Russia about the same. Deaths per year in Russia outnumber births by about 1m. Russia has a median age of 40 currently, and Japan 48. USA is 38, a year less than China's 39. African countries are younger, although their growth is also slowing (but much less than elsewhere).
In the modern era, no country that has fallen below population replacement fertility of 2.1 has been able to get back above it.
To put the US in context, though, compared with Russia and Japan, you have to consider that if the US didn't have largescale immigration, it would not be growing either. Note that US is still by far considered the most desirable country to relocate to, and is the population with the most immigrants.
An older population is also more female (since males are more likely to die of just about every cause of death except for things men can't die from because they don't have the body parts). Over the age of 40, there are less men and more women. At age 100 it's 5 to 1.
There might be a population bust by 2050. Less consumption (neither older people nor robots buy as much as younger). Less innovation (it is guessed).
In the US and Canada, the most common household is a person living by themself. At the start and at the end of their adult life.
Female cosmetic surgery, supporting money, transportation from countryside. Reduced pressures. More things for families. Robots as consumers.