20.2.1 The Growth of Cities

According to sociologist Gideon Sjoberg (1965), there are three prerequisites for the development of a city: First, good environment with fresh water and a favorable climate; second, advanced technology, which will produce a food surplus to support nonfarmers; and third, strong social organization to ensure social stability and a stable economy. Most scholars agree that the first cities were developed somewhere in ancient Mesopotamia, though there are disagreements about exactly where. Most early cities were small by today’s standards, and the largest was most likely Rome, with about 650,000 inhabitants (Chandler and Fox 1974). The factors limiting the size of ancient cities included lack of adequate sewage control, limited food supply, and immigration restrictions. For example, serfs were tied to the land, and transportation was limited and inefficient. Today, the primary influence on cities’ growth is economic forces. Since the recent economic recession reduced housing prices, researchers have been waiting to see what happens to urban migration patterns in response.