An opinion can be called "Tian Jun's first theory". According to the records in Shu Wei, people who hold this view think that after the promulgation of the land equalization system in the Northern Wei Dynasty, they felt that it was difficult to implement the land equalization system without strict grass-roots organizations, so they set up a three-long system to rectify their household registration. Ikeda Wen, Korea Pan and Wei all hold this view. [2] Li Anshi's promotion is considered to be in Taihe for ten years or later.
Another opinion belongs to the "three long first stop". From then on, according to the records in the Book of the Southern Qi Dynasty, the Speaker believed that the three-long system was established in the ninth year of Taihe, earlier than the equal field system. Japanese scholar Zhi Tian did not move, and later China scholar Miao Yue came to a similar conclusion. Zhu Shaohou and Gao Min also agree with this statement.
The third opinion, represented by Tang, holds that the three-long system was established in the tenth year of Taihe, and the land equalization system was not formally implemented until the fourteenth year of Taihe. For three long years, I agree with the first theory.
In addition, Japanese scholar Horaido also believes in Shuwei, but he thinks that the two systems were originally conceived separately, and the implementation of the three-long system was later than the promulgation of the equal land system. In order to implement the land equalization system, the three-long system has become necessary, and the real implementation of the land equalization system needs 12- 14 years in Taihe. Hori's view is close to that of Tang, but there are some differences. It can be regarded as the fourth theory.