In the beginning of the Western Han Dynasty, the government implemented a laissez-faire economic policy. As a result, it brought many negative impacts to the society. The rich became richer and richer；the landholders annexed more and more lands. Some local forces were so strong that the government felt the menace of the spreading.

After Liu Che was crowned (known as Emperor Wu, Han Wu di), he started a economic reform. He asked his citizens to pay estate tax and income tax. Merchants, usurers and handicrafts industry owners must declare their assets. in order to prevent from making a false report of asset, the government performed the incentive system and used bonus to encourage insiders to tell the truth.