ancient cities

produced have emerged from several different disciplines,
with each taking a unique approach to the
question. Economic explanations often focus on
why cities so often look the same and seek to identify
the common forces that lead them to have
similar forms. The ecological approach, in contrast,
emphasizes the differences among cities that
result from competition for resources in a
Darwinian framework. More recently, critical
geography or new urban sociology suggests that
these earlier perspectives neglect structures of
power and dominance.
The economic view of urban space considers
cities the equilibrium between two competing
forces. Centripetal forces draw businesses toward
the center as they seek economies of scale associated
with proximity, and they draw people in as
they seek greater access to the goods and services
available in the city. At the same time, centrifugal
forces push people and businesses away from the
center as they seek cheaper land and less congestion.
These ideas originated in the nineteenth-
century work of Johann Heinrich von Thünen and
culminated in William Alonso’s bid-rent function,
which suggests that the use of a particular location
in urban space will be defined by its distance from
the center of the space. Similarly, Walter
Christaller’s central place theory suggested that the
characteristics of a city are a function of its size
and its distance from other cities.
The ecological view also sees (the form of)
urban space as the result of competing forces but
relies on a biological metaphor that draws parallels
between cities and organisms and emphasizes
the role of competition and differentiation. Herbert
Spencer and Émile Durkheim first adapted
Darwinian thinking about the natural world to the
social context, but in the urban context Robert
Park, Ernest Burgess, and Roderick McKenzie formalized
these ideas as the Chicago School of Urban
Sociology. This approach suggests that the development
of transportation and communication
technologies bring individuals into more frequent
and intense interactions in ever-denser urban
spaces, thereby spurring a competition for limited
resources such as land and jobs. This competition
forces individuals to differentiate and specialize in
narrower activities, leading to a finer-grained division
of labor and land use. A similar process of
competition and differentiation also occurs for
Urban Space
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entire urban spaces, when cities specialize in specific
activities to avoid competing with other cities.
For example, the Silicon Valley region specializes
in the manufacture of computer chips but not in
the manufacture of potato chips, which must be
imported from other cities specialized in agriculture
and food processing. Of particular importance
here is the notion that all cities occupy a system of
cities within which they interact with, and are
interdependent upon, one another.
Critical geography and the new urban sociology
emerged as a response to the economic and ecological
approaches, which were viewed as deterministic
and not accounting for structures of
power. Mark Gottdiener, Harvey Molotch, and
Sharon Zukin have focused on the role of local
political and business elites and, more generally,
the role of local power structures in allowing specific
individuals to maintain disproportionate control
over the development of urban space. Others,
like Saskia Sassen, have examined how the features
of urban space are the result of a capitalist mode
of production that stratifies individuals into ownership
and labor classes with differing amounts of
power, focusing especially on how globalization
and the new international division of labor has had
differential effects on major cities in developed
(e.g., New York, Tokyo, London) and developing
countries (e.g., Mumbai, Jakarta, São Paulo).
The Meaning of Urban Space
The complexities of urban space, its form and production,
beg the question: How is urban space
navigated in everyday life? Answering this question
requires distinguishing the closely related
concepts of “space” and “place.” Space refers
abstractly to a physical location and its contents,
with urban space being simply a special case where
the location is densely populated. Spaces become
places when individuals assign them meaning and
social significance. A city and a street are examples
of spaces, existing only as material locations in the
physical world, but New York City and Wall
Street are examples of places, conjuring specific
histories and identities. Thus, urban space is navigated
by assigning it meaning and transforming
the abstract aggregate into a mosaic of places.
The concept of “sense of place” refers to the
character or essence of a place that results from the