China must manage the largest urbanization in human history

Nation must balance theinterests of all areas as it pursues goal of forming nearly 20 city clusters

China's undergoing the largest-scale urbanization in human history. At least 100 million rural inhabitants of the world's third-biggest country will become urbanites by 2020.

The government's challenge is to properly manage that movement. In what balance does it spend to develop villages and counties? And where does it draw the line in making big cities such as Beijing and Shanghai bigger?