3. Beijing phases out non-capital functions

According to Beijing's development plan, during the period from 2016 to 2035, the city's key functions politics, culture, international communication and technical innovation will be prioritized, while other sectors will be moved out of the capital.

Over the past four years, Beijing has shut down 1,992 manufacturing businesses that heavily pollute or do not fit the capital's functions.

The city's famous wholesale markets in the Dahongmen and Beijing Zoo areas, as well as 61 industrial compounds in the suburban Daxing district, also have been closed to reduce traffic congestion and population.

Beijing's service sector now accounts for more than 81 percent of local GDP. In 2017, finance, scientific and technological services, and IT industries contributed more than 53 percent of the city's economic growth.

In addition, the number of Beijing's permanent residents dropped by 0.1 percent to 21.7 million by the end of 2017, the first reduction since 2000.