Since I went to school and was taught about economics, I concluded that too large a population is a serious problem for the economy, but after many countries reported population shortages because many people did not want to have children, it now creates a more complicated problem, many places or cities now have to look for workers cheap labor from abroad thereby making production costs higher.
Under population is not very good and that is what will make a country open their borders for foreigners out of need for labour force. I think there is a solution to this through government policy by giving rewards to couples who increase the numbers of children they give birth to depending on the number stipulated by government. Another point is to discourage abortion because people do that as final resort when they have no other option.