In 266 AD, after the painstaking management of three generations of the Sima family, Sima Yan naturally inherited the Cao Wei Empire, changed the name of the country to Jin, and became Emperor Wu of Jin.
In 280 AD, the Jin Dynasty successfully destroyed Sun Wu, realized the unification of three points into one, and achieved an unprecedented and short-lived Great Jin Dynasty.
The Jin Dynasty's path to the founding of the country was perfect, neither the fierce battles with ethnic minorities like the Ming Dynasty, nor the bloody battles of the Tang and Song dynasties.
Fortunately, the Jin Dynasty faced a rather comfortable external environment after its founding, and there was no minority regime around it that could compete with it.
The demise of the Western Jin Dynasty is believed to be the result of the Rebellion of the Eight Kings and the Five Hu Rebellion. So, what led to the end of this great age? Let's approach this topic from an economic point of view.
First, let's start with a story. The protagonist of the story is Du Pre, who is an important ** in the Western Jin Dynasty, and has served as Henan Yin, Anxi Military Division, Qinzhou Thorn History, Duzhi Shangshu and other positions.
He is best known for his outstanding performance in the battle to destroy Wu, which was the last battle of the three families to return to Jin, and Du Pre made great contributions in this battle. However, Du Yu was not a general who could only fight.
He was more adept at farming, because agriculture was the most important industry in ancient society. In that era, people took food as the sky, and only the rations of the people could stabilize the country.
Therefore, in the autumn of the fourth year of Xianning (278), when the counties of Yanyu suffered from a large area of flooding, Emperor Wu of Jin immediately sent him to solve the problem.
The story tells us that Du Pre is a rational and attaches great importance to people's livelihood, and his governance experience enlightens us that only by putting people's livelihood issues in the first place can the country maintain stability.
When Du arrived in the Yuzhou area, he found that the flooding was not due to the lack of dikes, but to the fact that too many dikes had been built on the river, forming private dikes and hindering normal drainage.
He ordered the demolition of illegal buildings, but was opposed by the local family. Du pre-usual is resolute, but this time he chose to avoid his edge.
These opposing clans have a deep background and occupy important areas such as Yingchuan County, and they are the Yingchuan Shi group.
The demeanor of the three giants of the Yingchuan scholar clan - the celebrities and historical contributions of the three major scholars of Xun, Zhong and Chen Text: In the Yingchuan area, there are outstanding people and many scholars, among which the three major scholars of Xun, Zhong and Chen contributed almost half of the top governing talents at that time.
The most famous are Xun Yu, Xun You, Chen Qun and Zhong Xuan. Let's pay special attention to the Xun family, at that time the Xun family had two powerful figures in the imperial court, Xun Yi and Xun Xun.
Xun Yi is Xun Yu's sixth son, and he stepped into officialdom, in addition to his father Xun Yu's exploits and his own fame, mainly relying on Sima Yi's support.
Xun Yi assisted Sima Yi in launching the coup d'état in Gaopingling, and since then he has been closely bound to the Sima clan, and on the road of Sima's usurpation of power, Xun Yi has always been a staunch supporter of the Sima clan, and finally became a lieutenant and was crowned the Duke of Huaikang.
Another member of the Xun family, Xun Miao, is the great-grandson of Xun Shuang, who served as an important advisor to Sima Zhao, and later worshiped the Chinese secretary and servant, and was in charge of secrets for many years.
Under his support, Xun Miao's younger brother Xun Group also became an official to Sikong, Situ, and Taiwei, and Xun Miao's son Xun Fan also served as Sikong. The Xun family reached its peak in the Western Jin Dynasty, and its main land production was in the Henan region.
However, the Xun family was the main person who came forward to obstruct the floods in Henan recently.
Du Zhen knew that the water was too deep, and he couldn't afford to provoke the Xun family, so he had to return to the imperial court, submit a letter to Chen, and report the situation to Emperor Wu of Jin, hoping that he would come forward to issue an edict to solve the flood in Henan.
Every year, floods break the levees and replace fertile farmland with lakes and swamps, leaving people living in this predicament. The uncoordinated direction and use of the water flow leads to the depletion of pastoralism and the death of trees, which are all problems caused by the levees.
If there are too many dikes, then the land will become barren and the water will become shallow, and the rain will not be able to moisten the earth. As a result, every time there is rain, it floods again, affecting the surrounding land farmland.
Propose a solution: He believes that the unreasonable dikes should be demolished, and that the old Han and private houses in the valley can be repaired to prevent flooding.
"As a matter of common sense, there is no reason to accumulate useless water, especially now that the water is so waterlogged that it has caused serious damage," he said. I suggest that instead of making the wrong decision, these dikes should be demolished instead of storing water. ”
Bad plan: The Wei family has built since the establishment and the rain to overflow the reeds, horse intestines, etc., all of which are decided, "It is advisable to destroy the eastern boundary of Yanyu and preach it as it returns." ”
If this plan can be realized, then next year, the Henan region will return to the scene of abundant grains. "After the water recedes, the fields can be filled with silt, and several hours of grain can be harvested per acre.
In the spring, if you plant a large area of grains, you will definitely have a bumper harvest, which will be a big profit next year. Why the Emperor Rejected Du Yu's Plan: However, Emperor Wu of Jin did not adopt Du Yu's plan.
In the two Jin Dynasty periods, the status of the scholar clan was very high, and in the Eastern Jin Dynasty, there was even a saying that "the king and the horse, the world", which means that the Langya Wang family and the royal family at that time were evenly matched during the Eastern Jin Dynasty, and even surpassed.
The emperor didn't dare to offend the scholars, so he vetoed Du Yu's plan. External problems: For the Xun family in Yingchuan, don't they understand the stakes?
No, for the wealthy people of Yingchuan, they have a strong incentive to build dams, although the cost of building dams is very high, for the builders, building dams can prevent flooding, and avoid flooding their own fertile land when floods come.
From an economic point of view, this behavior can reduce losses and generate a positive profit, so they will have an incentive to build this dam.
However, for the whole of Henan, because you only have to build the dam yourself, regardless of the impact of flood discharge, the social cost of building the dam will become very large, because the small dam groups everywhere will block the normal drainage and eventually cause greater flooding.
But these families don't care, anyway, if there is a flood, the damage will be shared by everyone, but the benefits of building the dam itself are exclusive to my family.
So they mobilized the relatives of the executives in the capital to force the emperor not to adopt Du Yu's plan.
Summary: This is the concept of "externality" in economics, that is, the activities of an individual economic actor benefit others or society, and the beneficiaries do not have to pay the price, which is the positive externality of the economy.
However, a negative externality is one in which the activities of an economic actor cause damage to others or society, and the person who causes the negative externality does not bear the cost.
Coase's theorem tells us that in some cases, economic externalities can be corrected through negotiations between the parties to maximize social benefits.
* In order to solve such problems, it is first necessary to clarify the property rights, such as giving the surrounding residents the right to use the surrounding factories, and asking the factories to pay compensation costs.
In this way, the factory owner will consider whether it is more cost-effective to pay compensation or whether it is cheaper to invest in the equipment to reduce the pollution themselves. A similar approach can be used for the flood problem of the Jin Dynasty.
The imperial court declared the land to be its own, and the wealthy who needed to build the embankment had to pay a large fee for the use of the dam. The Hao would calculate how much damage would be incurred in the event of a flood if the levee was not repaired.
If the value of this loss is greater than the royalty of the imperial court, they will choose to build the embankment; If it is low, they will not fix it. Through this large amount of money, the imperial court can provide more disaster relief subsidies to local farmers in the event of floods.
However, the emperor did not adopt Du Pre's plan, because the scholars represented by the Xun family strongly opposed it. This reflects the fundamental reason for the fall of the Jin Dynasty: the power of the scholars was too large, which led to the weakening of the control of the local area and the forced decentralization.
The scholars only cared about their own family interests, and did not take into account the interests of the imperial court as a whole.
In February, the Western Jin Dynasty may be the weakest court in history, and the local tyrants and scholars in various places controlled local affairs, and the same as the **imperial court**, causing the will of the imperial court to not reach the masses at the bottom.
For this situation, the imperial power was no longer able to confront the wealthy family. The emperor of the Sima clan had no choice but to divide his relatives into large countries to become kings and control military and political power, hoping to use this to fight against the Shi clan and the local powerful forces.
Unexpectedly, these princes and kings eventually became the key factor in subverting the Western Jin Dynasty.