For centuries past, often driven by political upheaval or famine, Chinese have migrated to southeast Asia and beyond, to far flung corners of the globe. Large old 'Chinatowns' in cities such as London, Toronto, New York and San Francisco attest to these earlier migrations. Chinese continue to emigrate in large numbers in the 21st century-but this time around circumstances are different. Often encouraged and even facilitated by the Chinese state-officially...