The University of Chicago economist and Nobel laureate Robert Lucas declared that the spillovers in knowledge that result from talent-clustering are the main cause of economic growth. Well-educated professionals and creative workers who live together in dense ecosystems, interacting directly, generate ideas and turn them into products and services faster than talented people in other places can. There is no evidence that globalization or the Internet has changed that. Indeed, as globalization has increased the financial return on innovation by widening the consumer market, the pull of innovative places, already dense with highly talented workers, has only grown stronger, creating a snowball effect. Talent-rich ecosystems are not easy to replicate, and to realize their full economic value, talented and ambitious people increasingly need to live within them.