LAYERCITY

Society was born with social structure. Different layers have different duties. If the city wants to be flexible,there must be enough layers to remit

the social stress especially during economic crisis. If there are only two layer which form the society, people in the first layer can jump to the lower layer, but those who are in the second layer will not be so lucky to escape, because it is no easy things to learn a higher skill in a very short time. Suppose there are more layers, all could support each other, and it will be much easier for job-hopping. Society would be more flexible.