From the middle period, the basic society was destroyed and many yeomen were reduced to servants, because of land centralization and ineqality of taxes and labor services.

• 由于地权的集中和赋役负担的不均，自中期后导致了基层社会体系的破坏，大量的自耕农沦为奴仆，从而使奴仆存养现象普遍化。