That only solves one of the problems and the GP was talking about limited resources which doesn't change even if you make the income/wealth distribution equal.

That only solves one of the problems and the GP was talking about limited resources which doesn't change even if you make the income/wealth distribution equal. One person would still need 8 litres of water, a piece of land, food and other essential limited resources. How do you plan to let all the people have kids with an existing population density of 828 persons per km² without ruining it for everyone? What other filter do you propose is realistic? Do you think there should be a test, higher age requirement, education background or something? Clearly, the current population is too much here. Sure it is declining (predicted to be normal replacement fertility rate by the end of 2020) but that will take long time to materialize and then you have government doing something to stop it because failing economy. Why even set your whole structure in a way that requires numbers? This is a perverted incentive and should be stopped. https://link.springer.com/article/10.1007/s10668-015-9711-5 https://link.springer.com/article/10.1007/s10668-015-9711-5 Optimum world population is something around 2 billion. Not 8 billion and growing.