Guangzhou could contain another 4m people if it was as packed as Seoul in South Korea; Shenzhen could be larger by 5m.
But it might come as more of a surprise to learn that the largest 300 cities, from New York to Guangzhou, account for nearly half (48%) of world economic output... yet contain only 19% of world population.
The minimum wage in Guangzhou, a Chinese industrial hub, is $10.5 per working day.That might appear to be good news.
Roosevelt's grandfather lived in Canton (now Guangzhou) as a merchant for many years and the Roosevelts felt this particularly strongly.As a young man, FDR had been influenced by Admiral Mahan and his school, who taught in terms richly dipped in racism and eugenic theory, that the Japanese were destined to be America's enemy and could never be assimilated.
Guangzhou, the richest city in mainland China and therefore a magnet for migrants, has recently banned mopeds and motorbikes, supposedly to reduce congestion and crime but in reality to discourage job-seeking incomers.
Droughts seem to be ever more frequent in northern China, and southern cities such as Guangzhou are also affected.
In cars, all of the many announced joint-ventures between foreign multinationals and Chinese companies except one (Honda's, in Guangzhou) will sell only to the domestic market.
Honda entered China late but cheaply, snapping up Peugeot's Guangzhou plant for $250m in 1998 when the French retreated.
Geely, a carmaker, withdrew its support of a club in the southern city of Guangzhou in 2001, just eight months after agreeing to invest.
An executive of Guangzhou Pharmaceutical FC, Mr Yang and his club had agreed to pay 200,000 yuan to another club to throw a game in 2006, so Guangzhou could get promoted to the Chinese Super League.The rot of corruption went to the top: Nan Yong, then boss of the Chinese Football Association.
It is helping to build a "knowledge city" in Guangzhou, where it provides social services and plays a part in protecting intellectual-property laws.
