I don't know if we ever had quotas. I don't know what it used to be based upon. Was it ever "everyone is welcome" with no limit? I wouldn't know where to begin to have a number in mind. And do you apportion it out by country? Upon what would you base the numbers? Anyone?
Well ... the first step in determining that number, is to know what we want the population to be.
I think we should be able to support 100% of our population with our own resources (food, clean water, energy, clean water, garbage disposal).
So do we want the population to grow, stay the same, or even shrink? (based on what we can support, and current population)
Note we don't HAVE TO have the maximum population we CAN support.
The average family consists of 3.14 persons in 2018, down from 3.7 in the 1960s. This is reflected in the decrease of children in family households overall.
I think to maintain the population, we would need 4 person/family (2 parents + 2 children).