There's a big exodus happening inside China. Cities are becoming crowded because the life in the rural areas is just short of absolute poverty levels. Many cities are growing at incredible speeds while others get deserted in a flash. But I don't think that shows the true drama of the chinese population...
This exodus is not one we are accustomed to see. What is happening to many rural families is fragmentation. The father leaves to one city to get himself a job, the mother moves to another city to get herself a job. The children are left behind, usually at the care of the elderly, sometimes not even their relatives. The parents work the whole year only rarely being able to come home to visit. They send all the money they can home. though. Some villages in the countryside are missing an whole generation. Children play at home, help the grandparents in the fields or go to school. The parents... are working somewhere in China.
A major driving force of Chinese cities population levels is the working class with established homes in the rural areas.
