For a point of reference, the per capita income variation in the United States between the richest and poorest states—Maryland and West Virginia—is just under two-to-one. In China the variation between richest and poorest—between ultra-urban coastal Hong Kong and ultra-rural interior Gansu—is nearly ten-to-one. Even that understates the possibilities for synergies. Since 1995, China’s major cities have added some 500 million people, mostly migrants from the country’s ultra-poor interior, absolutely swamping every urban center with ultra-low-cost labor.
