Chinexe population problem

You can see the population density in the picture.
Chian has the third largest territory, but at same time, almost 1/4 world population is in China. Most of populaitin are living in the eastron of China.
Chinese government is using family planning to control to population booming. Only a child is allow to be born in every family, or you need pay a lot of extra taxation.
With the development of Chinese socitey and medicine, people living much longer than before. To support retired people is becoming a big problem for Chinese, because the population of retired people is huge and most of them didn't have their pension.