There are a dozen regional powerhouses in the US economy.
Similar mega-regions have been identified in EU. Europe’s largest mega-region spans Amsterdam-Rotterdam, Ruhr-Cologne, Brussels-Antwerp and Lille. Other mega-regions include the British mega-region, the Italian mega-region, Greater Paris and the Euro-Sunbelt mega-region.
China’s mega-regions, together with metropolitan cities, become the engine for economic development, and the target areas for regional and national policies. Apart from the three giant mega-regions—Capital Economic Zone, Pearl River Delta and Yangtze River Delta—which account for a large share of the country’s economic output, several other inland mega-regions are also emerging and developing. These 10 mega-regions as identified by China’s National Development and Reform Commission, cover around 20% of the total area of China, and include more than half of national population (census 2000 data) and 52% of GDP
We have reviewed the Bohai megaregion aka the Capital Economic Zone which includes Beijing and Tianjin aka the Jing-Jin-Ji region.
There is an update to the planning around Beijing.