partial_accumen , 4 months ago

Still increasing population, but the rate at which we are increasing has slowed.

This statement suggests that we can’t do math and can’t accurately predict whats going to happen with population increases or decreases. We know how old a human being generally has to be to give birth, and we know how many humans we have of each cohort. Its pretty easy to see that what the population increases or decreases will occur when the younger cohorts come of age.

The number we care about is “replacement rate”. A growing replacement rate is: 2.1. This means that each parent will replace themselves with a new child, and then 1 tenth of another. Practically this means 9 out of 10 of two parents have two children and the 10th of 10 parents will have 3 children.

So we just have to look up the replacement rate for each country, and for it to grow from domestic population growth alone.

Countries being discussed in trouble:

• Russia = 1.42 source
• China = 1.15 in 2021, is now approaching 1.0 source

Country being discussed doing okay:

• USA = 1.67 source

So why is the USA okay while China and Russia are in a bad place if everyone is below 2.1? New births aren’t the only way to increase a country’s population. Immigration also works.

• Russia = 0.626 per 1000 population source
• China = negative 0.253 per 1000 population source
• USA = 2.768 per 1000 population source

So with immigration the USA is doing fine and dandy, Russia is barely holding on while marching its child bearing age men into the meat grinder of war, and China is having people not have babies all the while thousands of them are leaving the country at the same time.