Editor's note: Megalopolis, including the Yangtze River Delta, the Pearl River Delta, the Beijing-Tianjin-Hebei region, and the Chengdu-Chongqing region, are leading China's social and economic development. How many megalopolises are there in China? How should their development be compared and evaluated? Which one of them is the most developed megalopolis in China? Cloud River Urban Research Institute has tried to comprehensively evaluate the development of megalopolis in China based on its China Integrated City Index.

Megalopolis is a primary embodiment of new urbanization in China. After releasing the China Integrated City Index 2021, Cloud River Urban Research Institute has conducted an all-round examination of the top 10 megalopolis out of the 19 currently planned by the government, and comprehensively evaluated the strength and development of each one of them. The 10 megalopolises — the Yangtze River Delta, the Pearl River Delta, the Beijing-Tianjin-Hebei region, the Chengdu-Chongqing region, the middle reaches of the Yangtze River, the coastal areas of Guangdong, Fujian, and Zhejiang, the Shandong Peninsula, the Beibu Gulf, the Central Plains, and the Guanzhong Plain — involve 173 cities at the prefecture level and above. With a combined population and GDP respectively accounting for 69.9% and 77.7% of the national total, they constitute the most important platform for China's social and economic development.

Zhao Qizheng, former minister of the State Council Information Office of China, commented that one of the major features of this edition of the China Integrated City Index is a focused analysis of megalopolis, and an effort in line with my long-held expectations for index-based research. 

He said megalopolis have already become a primary embodiment of urbanization in China now, with the radiating capacity of the three major ones — the Yangtze River Delta, the Pearl River Delta, and the Beijing-Tianjin-Hebei region — extensively recognized. 

He added that through an analysis and evaluation of the comprehensive strength, development differences, and problems of the 10 megalopolises, the China Integrated City Index offers instrumental value on understanding megalopolis policies and urban development. 

"I hope it can arouse the attention of leading officials of Chinese cities and sociologists," he said.

1. Categorization of megalopolis based on Competitive Advantage Index

The 10 megalopolises can be divided into the following three categories by the Competitive Advantage Index (per capita GDP/average national per capita GDP×100): (1) large megalopolis with a Competitive Advantage Index much higher than 100 and strong economic advantages over other regions of the country; (2) megalopolis with a Competitive Advantage Index around 100; (3) megalopolis with a Competitive Advantage Index much lower than 100.

With a Competitive Advantage Index as high as 171, 158, and 124 respectively, the Yangtze River Delta, the Pearl River Delta, and the Beijing-Tianjin-Hebei region fall into the first category. These three major megalopolis account for 36.6% of the country's total in terms of GDP, and have attracted a large population from all over the country to seek development with their strong economic advantages. Today, they have 31.98 million, 39.09 million, and 9.08 million permanent residents without urban household registration, respectively, comprising the only group of regions with net population inflows among the 10 megalopolises. In particular, only one out of the nine cities in the Pearl River Delta has a net population outflow. In Shenzhen, the most typical city among them, permanent residents without urban household registration account for 66.3% of all its permanent residents.

With long-term inflow of a large population, permanent residents of these three-megalopolis account for as high as 23.5% of the country's total. 

Professor Zhou Muzhi, head of Cloud River Urban Research Institute, noted that there is no doubt that the three major megalopolis, with nearly a quarter of China's population, are leading the country's development. 

He commented that thanks to young and middle-aged migrants, working population (aged 15-64) accounts for as high as 72.9% and 65.2% of the total population in the Pearl River Delta and the Yangtze River Delta, respectively, and such a population structure injects strong vitality into the two regions. 

Notably, the proportion in the Beijing-Tianjin-Hebei region is merely 62%, even lower than the national average of 63.4%."

With a Competitive Advantage Index around the national average level — 91, 103, 102, and 101 respectively, the Chengdu-Chongqing region, the middle reaches of the Yangtze River, the coastal areas of Guangdong, Fujian, and Zhejiang, and the Shandong Peninsula fall into the second category. But influenced by the strong appeal of the three major megalopolis, these four megalopolises have all seen net population outflows, at 7.23 million, 7.81 million, 3.59 million, and 200,000, respectively.

With a Competitive Advantage Index far lower than the national average level — 69, 68, and 73 respectively, the Beibu Gulf, the Central Plains, and the Guanzhong Plain fall into the third category. The economic gap has led to large population outflows, at 5.21 million, 24.74 million, and 1.69 million, respectively.

2. Interaction between core cities and non-core cities key to development of large megalopolis

The China Integrated City Index covers 297 Chinese cities at the prefecture level and above, and comprehensively evaluates their development from three dimensions — the environment, society, and the economy — with 882 sets of data. The data falls into 27 indicator groups under nine sub-dimensions of the three major dimensions. To make evaluations, the China Integrated City Index uses deviation values to reflect the position of each city relative to other cities of the country in terms of each indicator group, and converts the scale used in various indicator groups to the uniform one to facilitate comparisons. The national average deviation value for comprehensive evaluation, which integrates deviation values in environmental, social, and economic dimensions, is 150.

To make a more straightforward analysis of megalopolis development, this article divides the deviation values for comprehensive evaluation of the 173 cities involved in the 10 megalopolises, and analyzes the data with a box and beeswarm plot to display the distribution and differences of deviation values for comprehensive evaluation of the megalopolis.

The horizontal lines inside the boxes represent the medians of the samples, the top of the boxes represent the upper quartiles (75%), the bottom of the boxes represent the lower quartiles (25%), and the spaces inside the box indicate how 50% of the samples distributes. Beeswarm plot is a statistical chart that plots the distribution of individual data points. A combination of a box plot and a beeswarm plot shows the location of each sample and the distribution of the samples as a whole.

According to Figure 1 that shows the median of deviation values for comprehensive evaluation of 10 megalopolis, only two megalopolises, namely the Pearl River Delta and the Yangtze River Delta, exceed the national average, and the Pearl River Delta fares much better than the Yangtze River Delta.

The Yangtze River Delta has most core cities among megalopolis in China, including Shanghai, Hangzhou, Nanjing, Ningbo, and Hefei. Moreover, Shanghai's comprehensive ranking is second only to Beijing. In contrast, the Pearl River Delta only has two core cities -- Guangzhou and Shenzhen -- and their comprehensive rankings are both behind Shanghai. The median of the Pearl River Delta is much higher than that of the Yangtze River Delta, because better comprehensive evaluations of non-core cities such as Foshan and Dongguan help to raise the overall level in the region, with only one city in this region registering deviation value lower than the national average. In comparison, 10 cities in the Yangtze River Delta have lower comprehensive evaluations than the national average.

Tang Jie, former deputy mayor of Shenzhen and board member of the Shenzhen Finance Institute of the Chinese University of Hong Kong (Shenzhen), noted that China has entered the era of megalopolis development, where super-large cities and large, medium, and small-sized cities mutually reinforce, forming a new driving force for China's economic and social development.

Zhou echoed Tang's opinion, saying that the development of megalopolis is underpinned by the strength of core cities, and that whether they can bring a large number of non-core cities to a higher level of development is an important gauge of their development.

In this regard, the development gap between cities in the Beijing-Tianjin-Hebei region is relatively prominent. Although the region is led by Beijing, which ranks first in the comprehensive ranking, and Tianjin, its median of the comprehensive valuation deviation is only ranked eighth among the 10 megalopolises. Its poor ranking is also due to the poor performance of the region's another core city Shijiazhuang as well as the fact that the comprehensive evaluations of all non-core cities in the region are below the national average level.

Figure 1. Comprehensive evaluation of 10 megalopolis in 2021

3. Inclusiveness and diversity key to cities' social development

China is experiencing the largest population migration in human history. Among the 10 megalopolises, only the Yangtze River Delta, the Pearl River Delta, and the Beijing-Tianjin-Hebei region have attracted net inflows of population. They are the first-level reservoirs for the large-scale population migration in China's urbanization, and have absorbed a large number of people from around the country.

Core cities are the second level reservoir for population migration. Among the 23 core cities in the 10 megalopolises, the 10 core cities in the three major megalopolises have experienced net inflows of population. Among the other 13 core cities in the seven megalopolises, 12 have net inflows of population. These core cities have the "siphon effect" on their surrounding areas, attracting a huge mobile population. Only Chongqing, due to its vast territory and large population base, has a net outflow of population.

Zhou pointed out that the influx of a large population has helped 14 of the 23 core cities in the 10 megalopolises grow into megacities with a population of over 10 million. Some megacities with a population of over 9 million, such as Ningbo, Hefei, Nanjing, and Jinan, are playing catch-up and are set to become super large cities in the near future."

Yang Weimin, deputy director of the Economic Affairs Committee of the CPPCC National Committee, emphasized that the proposal at the 20th CPC National Congress to accelerate the transformation of the development mode of super large and megacities has charted the course for super large and megacities on China's new journey of building a modern country comprehensively. 

He said, first, we need to strike a balance between economic development, well-rounded human development, and sustainable development in terms of space. That means we should not only focus on economic development and urban construction while neglecting comprehensive human development and ecological environment protection. He pointed out that the China Integrated City Index has taken a science-based approach by taking the indicators of economy, environment, and society into account. 

He said, second, we need to enhance the inclusiveness and diversity of cities and develop different occupations on an equal footing. Unbalanced development of occupations will increase the cost of living in cities and ultimately damage the development of cities.

Figure 2. Comparison analysis of permanent populations in 10 megalopolises