ancient cities

the location of demolished buildings or the incidence
of tuberculosis.) These maps showed the
percentage of the total juvenile population of the
area who were involved in the criminal justice
system. The main conclusion was that neighborhoods
with the highest delinquency rates were
found to be located within or immediately adjacent
to areas of heavy industry and commerce,
areas of rapid population decrease, and areas of
population with low economic status, and areas
of high concentrations of immigrants and minorities.
According to this view, delinquency and
other social problems are closely related to the
processes of invasion, dominance, and succession
that determine the concentric growth patterns of
the city. When new residents invade a particular
location of the city, the established social relationships
and the natural organization of the area are
severely impaired. The formal social organizations
that existed tend to disintegrate as the original
population retreats, the residents no longer identify
with it, and the ability of people in the neighborhood
to control their youth decreases. The
area tends to become a battleground between the
invading and retreating cultures. In other words,
the social disorganization of the neighborhood is
the main factor associated with rates of juvenile
delinquency.
Urban ecology has gone through a series of critiques
through the years. Some rejected the ecological
theory of urban form, asserting that forces other
than economic competition for central location may
produce the city’s land use gradients. Sentiments
and symbolism can create land use values differences
as well. An additional line of critique was
directed to the argument that population competition
results in unplanned natural areas. Scholars
associated with the new urban sociology paradigm
directed attention to the role of the government,
land owners, and real state agents, who are powerful
actors operating in the sociospatial shaping of
urban form. Finally, a further critique was to the
lack of consideration of the global context of urban
development and the place of cities in the strategic
investment decisions of large international corporations
in the real state market. Yet, urban ecology is
still an important framework in the study of residential
segregation and urban social problems.
Gustavo S. Mesch
Urban Economics
See also Chicago School of Urban Sociology; Human
Ecology; Urban Sociology; Urban Theory
Further Readings
865
Barry, Brian and John Kasarda.1977. Contemporary
Urban Ecology. New York: Macmillan.
Burgess, Ernest W. 1925. “The Growth of the City.”
Pp. 47–62 in The City, edited by R. Park, E. Burgess, and
R. D. McKenzie. Chicago: University of Chicago Press.
Guest, Avery. 1984. “The City.” In Sociological Human
Ecology, edited by M. Micklin and H. Choldin.
Boulder, CO: Westview Press.
Park, Robert E. 1916. “The City: Suggestions for the
Investigation of Human Behavior in the Urban
Environment.” American Journal of Sociology
20:577–612.
Schwab, William, A. 1982. Urban Sociology: A Human
Ecological Perspective. Reading, MA: Addison-
Wesley.
Schwirian, Kent P. 1993. Models of Neighborhood
Change. Annual Review of Sociology 9:83–102.
Shaw, Clifford. 1929. Delinquency Areas. Chicago:
University of Chicago Press.
Ur b a n ec o n o m i c s
Economics is the study of decision making when
resources are limited and can be used in different
ways. In an economic model, a household makes
choices to maximize its utility or satisfaction,
whereas a firm makes choices to maximize its
profit. Geographers study how things are arranged
across space in order to answer the question of
where human activity occurs. Urban economics
puts economics and geography together, exploring
the geographical or location choices of utilitymaximizing
households and profit-maximizing
firms. These location decisions generate cities of
varying size, scope, and spatial structure. Urban
economics also applies economic analysis to some
of the problems that occur in cities, including poverty,
crime, dysfunctional neighborhoods, and congestion,
and explores the role of local government
as a part of the federal system of government.
An urban place contains a large number
of people in a relatively small area; that is, it has
a population density that is high relative to the