Good thread. One is good and two should be the max if the parents are capable of taking care of them, but after the first one or two gets older, I think one or two more is ok since the first one or two would be paying taxes. If a parent doesn't have the resources to raise a child, then they shouldn't have any.
I really don't know what I'm talking about
. I think two kids should be plenty to keep a family from vanishing. At the moment though, I think a couple or few countries should just calm down on the baby making machines.