While racial segregation in U.S. cities had reached its peak level by 1940, a new line of separation between whites and blacks emerged as a result of massive suburbanization in the next three decades.  As a result, studies that focused entirely on central cities in this period missed major structural changes in urbanization.  Urban scholars always have to be attentive to the actual scale at which place-based inequality is created and reproduced.  The same kinds of rescaling issues arise in China today, as urban development has become predominantly suburban.  At an even larger scale, the divide within metropolitan areas between local residents and migrants is rooted in a more fundamental regional divide between urban and rural China.  In all societies, conditions beyond the city limits are becoming increasingly crucial for the study of the city.