Today China has 130 million migrant workers. In factories, restaurants, construction sites, elevators, delivery services, house-cleaning, child-raising, garbage-collecting, barbershops, and brothels, almost every worker is a rural migrant. In large cities like Beijing and Shanghai, migrants account for a quarter of the population; in the factory towns of south China, they power the assembly lines of the nation’s export economy. Together they represent the largest migration in human history, three times the number of people who emigrated to America from Europe over a century.
— Factory Girls : From Village to City in a Changing China by Leslie T. Chang (3%)
Although the migration is internal, there are the same issues between migrants and 'locals' as for international migration, and a similar divide between Somewheres and Anywheres as in The road to somewhere