Diasporas have been a part of the world for millennia. Today two changes are making them matter much more. First, they are far bigger than they were. The world has some 215m first-generation migrants, 40% more than in 1990. If migrants were a nation, they would be the world’s fifth-largest, a bit more numerous than Brazilians, a little less so than Indonesians.
Second, thanks to cheap flights and communications, people can now stay in touch with the places they came from. A century ago, a migrant might board a ship, sail to America and never see his friends or family again. Today, he texts his mother while still waiting to clear customs. He can wire her money in minutes. He can follow news from his hometown on his laptop. He can fly home regularly to visit relatives or invest his earnings in a new business.
Such migrants do not merely benefit from all the new channels for communication that technology provides; they allow this technology to come into its own, fulfilling its potential to link the world together in a way that it never could if everyone stayed put behind the lines on maps. No other social networks offer the same global reach—or commercial opportunity.
This is because the diaspora networks have three lucrative virtues. First, they speed the flow of information across borders: a Chinese businessman in South Africa who sees a demand for plastic vuvuzelas will quickly inform his cousin who runs a factory in China.Second, they foster trust. That Chinese factory-owner will believe what his cousin tells him, and act on it fast, perhaps sealing a deal worth millions with a single conversation on Skype.
Third, and most important, diasporas create connections that help people with good ideas collaborate with each other, both within and across ethnicities.