WHAT IS A CITY? | WHAT IS TOWN

 WHAT IS A CITY?

An urban economist defines an urban area as a geographical area that contains a large number of people in a relatively small area. In other words, an urban area has a population density that is high relative to the density of the surrounding area. This definition accommodates urban areas of vastly different sizes, from a small town to a large metropolitan area. The definition is based on population density because an essential feature of an urban economy is frequent contact between different economic activities, which is feasible only if firms and households are concentrated in a relatively small area. The U.S. Census Bureau has developed a variety of geographical definitions relevant to urban economics. Since much of the empirical work in urban economics is based on census data, a clear understanding of these definitions is important. The appendix to this chapter provides the details of the census definitions. The key census definitions, some of which are new for the 2000 Census, are as follows.

1. Urban area:

A densely settled geographical area with a minimum population of 2,500 people and a minimum density of 500 people per square mile. In 2000, there were 3,756 urban areas in the United States.

2. Urban population:

People living in urban areas. In 2000, the urban population was 79 percent of the total population.

3. Metropolitan area:

A core area with a substantial population nucleus, together with adjacent communities that are integrated, in an economic sense, with the core area. To qualify as a metropolitan area, the minimum population is 50,000 people. In 2000, there were 361 metropolitan statistical areas in the United States.

4. Metropolitan area: A smaller version of a metropolitan area with a concentration of 10,000 to 50,000 people. In 2000, there were 559 micropolitan statistical areas in the United States.

5. Principal city:

The largest municipality in each metropolitan or micropolitan statistical area. A municipality is defined as an area over which a municipal corporation exercises political authority and provides local government services such as sewage service, crime protection, and fire protection. This book uses three terms to refer to spatial concentrations of economic activity: urban area, metropolitan area, and city . These three terms, which will be used interchangeably, refer to the economic city (an area with a relatively high population density that contains a set of closely related activities), not the political city. When referring to a political city, we will use the term central city or municipality .