WHY DO CITIES EXIST?

 WHY DO CITIES EXIST?

This is the fundamental question of urban economics. People need land to produce food and other resources, and living in dense cities separates us from the land where food is produced. As Bartlett (1998) points out, no other creatures in the animal world form anything like cities. Herbivores such as wildebeests and bison form larger herds but constantly migrate to fresh land to ensure a steady supply of food. Coral is concentrated in stationary reefs, but ocean currents provide a steady supply of food to the stationary coral. Perhaps the closest thing to a city in the natural world is a bee hive or an anthill. Eusocial insects such as bees andantes form colonies with thousands of inhabitants, with highly specialized castes— soldier ants, drones, breeders, nurses, and cleanup crews. In contrast with human cities, these insect agglomerations are closed to non-natives and not based on voluntary exchange. 

Cities exist because human technology has created systems of production and exchange that seem to defy the natural order. Three conditions must be satisfied for a city to develop.

1. Agricultural surplus.

People outside cities must produce enough food to feed themselves and city dwellers.

2. Urban production. 

City dwellers must produce something—goods or services—to exchange for food grown by rural workers.

3. Transportation for exchange. 

There must be an efficient transportation system to facilitate the exchange of food and urban products. Over this period, the urban share increased from 6 percent to 82 percent, a remarkable transformation that also occurred in other parts of the world. As we’ll see in the next three chapters of the book, the transformation of a rural society into an urban one occurred because technological advances increased the agricultural surplus (condition 1), increased the productivity of urban workers (condition2), and increased the efficiency of transportation and exchange (condition 3). with projections for the year 2030. In 1950, urbanization rates were relatively low in Africa and Asia, and highest in Oceania and North America. Between now and the year 2030, urbanization rates are expected to increase everywhere, with the largest increases in Africa and Asia. For the world as a whole, the urbanization rate was 30 percent in 1950 and is expected to double by the year 2030.

The New York area tops the list, followed by Los Angeles, Chicago, Dallas, and Philadelphia. The third column shows the percentage growth of each metropolitan area over the period 2000 to 2005. The most rapidly growing metropolitan areas were in the South, the Mountain States, and the West. In three metro- politan areas—Detroit, Pittsburgh, and Cleveland—population decreased over this period, continuing a two-decade trend of decreasing population. These metropolitan areas experienced large losses in manufacturing employment.

The table shows actual populations in 1975 and 2005, and projected populations for the year 2015. Eight metropolitan areas, all of which are in the developing world, are expected to grow by at least 20 percent over the 10-year period. In contrast, three cities in the developed world (Tokyo, Osaka, and Paris) are expected to grow slowly. In the United States, New York is expected to grow 6 percent over the period, and Los Angeles is expected to grow 7 percent.

In 1970, the two types of regions had roughly the same number of large cities. By 1996, however, the number of large cities in the less developed regions nearly doubled, and by 2015 there will be roughly four times as many large cities in less developed regions.