"'But what side on an imaginary line they live on doesn't matter at all. Jefferson Starship said it better : "It doesn't mean shit to a tree".'"


                  I would agree with that if, when people moved from one place to another, the population in the area they left went down. That, of course, is not what is happening now, so unless we want to sink the entire world in standing-room-only humanity, we need to control the migration.
                  We could make efforts to mitigate runaway population growth where it is occurring now, if the populations were agreeable to that, but so far, most of them haven't been.