Encyclopedia of Sociology

CITIES

settlements westward, as colonial seaports, river
ports, Midwestern railway towns, central places on
the Great Plains, extractive centers, and govern-
ment centers were integrated into an urban sys-
tem. A nationwide manufacturing base was estab-
lished by 1900, as were commercial and financial
centers. By 1960 a fully developed system of differ-
entiated urban centers existed within the United
States (Duncan and Lieberson 1970).

METROPOLITAN AREAS

In the United States, metropolitan areas are de-
fined as being of two kinds. Metropolitan statistical
areas (MSAs) are areas including one or more
central cities with a population of 50,000 or more,
or areas with a less densely populated central city
but with a combined urban population of at least
100,000 (75,000 in New England), including sur-
rounding counties or towns. Consolidated metropoli-
tan statistical areas (CMSAs) contain at least one
million population and may have subareas called
primary metropolitan statistical areas (PMSAs) (Frey
1990, p. 6). In 1990 a majority of the population of
the United States resided in the thirty-nine major
metropolitan areas: those with more than one
million population (Frey 1995, p. 276).

New urban-population-density patterns ap-
peared in the United States with the development
of metropolitan areas. Growth was characterized
by increases in population density in central cities,
followed by increases in density in the metropoli-
tan ring. Transport and communication technolo-
gies facilitated linkages of diverse neighborhoods
into metropolitan communities dominated by more
densely populated central cities. These linkages in
turn organized relationships between central cit-
ies and less densely populated hinterlands and
subcenters. Older metropolitan areas became the
centers of CMSAs, while newer areas were the
frontiers of expansion, growing by natural increase
and especially by net migration. Metropolitan
sprawl extended beyond many former nonurban
functions, as well as more centrally located older
features of the cityscape.

The interior of large Western metropolitan
areas represents a merging of urban neighbor-
hoods into complex overlapping spatial patterns,
which reflect to some extent the dates when urban
neighborhoods were settled and built-up. The blur-
ring of neighborhood distinctions, facilitated by

freeway and mass transit networks, facilitate inter-

action among ‘‘social circles’’ of people who are

not neighborhood-based. Meanwhile, urban neigh-

borhoods organized around such factors as status,

ethnicity, or lifestyle, also persist. As the city ages,

so does suburban as well as centrally located hous-

ing—a delayed consequence of the spread of ur-

ban settlement.

Kasarda (1995, p. 239) states that major cities

in the United States have been transformed from

centers of manufacturing and wholesale and retail

trade, to centers of finance, administration, and

information processing. Frey (1995, p.272) indi-

cates that during the 1970s and 1980s populations

concentrated in metropolitan areas with diverse

economies that emphasized service and knowl-

edge industries, as well as in recreation and retire-

ment areas. In the 1970s there was a metropolitan

and nonmetropolitan population turnaround.

Populations in smaller metropolitan areas grew

more rapidly than did those in larger metropolitan

areas and population in developing countries grew

more rapidly than in developed countries. In the

1980s, metropolitan population shifts, enhanced

by international and internal migration, led to an

urban revival, increasing regional racial, skill, and

age divisions, the suburban dominance of growth

and employment and more isolation of the urban

core (Frey 1995, pp. 272–275).

Residential moves—the individual counterpart

of population redistribution processes—are af-

fected by population characteristics and other fac-

tors. Elements that influence mobility decisions

are socioeconomic and psychological factors per-

taining to the family and the family life cycle,

housing and the local environment, and occupa-

tional and social mobility (Sabagh et al. 1969). For

each of these factors, conditions may restrain per-

sons from moving, or push or pull them to new

locations. Information concerning new housing

opportunities, the state of the housing market,

and the availability of resources may impede or

facilitate moves; subsequent moves may stem from

recent migration or residential turnover in the

metropolitan areas (Long 1988, pp. 219–224).

TRADITIONAL EXPLANATIONS OF CITIES

During the nineteenth century the character of the

Western city was seen as different from that of