I agree, the birth restriction ultimately needs to be done so that it matches what earth can handle. If earth can handle it then its ok to have x amount of children. Yea if a country's pop. is falling then the 1 child rule wouldn't apply to them, unless their pop. is still more than the land can bear. Tbh seeing how our soil is already getting depleted and sea life is being wiped out to fill our bellies we're well over the point where there's just too many people on the earth. All in all it would be a tricky thing to implement without inadvertently discriminating against other regions of people.