Between 1980 and 2020, China’s urban population grew from 190 million to 900 million, almost entirely due to internal migration from rural areas. The internal migration of 300 million persons was the largest migration wave in history.  At the same time, the number of foreign-born persons was miniscule. Shanghai in 1980 had 11 million population and virtually no foreign born. By 2020 its population doubled to 22 million, but in 2020 the foreign-born population was  less than 100,000.

This pattern is completely opposite that of major American cities. Take the forty years between 1870 and 1910. In 1870, New York City’s population was about 900,000 of which 45% were foreign born. By 1910, its population had grown five times to 4.7 million, its foreign born population share remained very high – 41%.

There was a common thread: in both cases, in-migration was by low income persons who formed the basis of a rapidly growing workforce. Large-scale economic growth occurs when an important source of relatively low cost resources is becomes available. In both instances this was migrating workers.