On March 365438, 2065438, the National Development and Reform Commission issued "20 19 Key Tasks of New Urbanization Construction", which mentioned "shrinking cities" for the first time, and explicitly requested that shrinking small and medium-sized cities should slim down and keep fit, strictly control the increment and revitalize the stock. These cities have the following characteristics:

1. Population decrease. With the continuous improvement of urbanization rate, the population flows from rural areas to towns, from small cities to large and medium-sized cities, and from underdeveloped areas to developed areas.

2. The proportion of tertiary industry is low. Manufacturing accounts for a relatively high proportion in the industrial structure of shrinking cities, and many college students can't go home to work because they can't find suitable jobs.

3. It is generally characterized by low wages and a high degree of aging. According to the data of the fifth and sixth population census in China, the urbanization rate of shrinking cities is often about 10 percentage points lower than that of non-shrinking cities. The proportion of people with college education or above in non-shrinking cities is 3.37 percentage points higher than that in shrinking cities, and the average salary of employees is more than 1 times of the latter. Shrinking cities are also aging.