Documentation
The geographic areas of nonmetro America exhibit a great deal of
variation in economic and social characteristics. In addition to
agricultural areas, nonmetro America includes sparsely populated
mountainous regions, millions of acres of heavily forested areas,
small towns, light manufacturing areas, tiny coastal hamlets, and
the suburban fringes of growing metro areas. What we know about
this heterogeneity is based largely on data for counties. This
means that our understanding of nonmetro diversity comes from data
on arbitrary political units.
Commuting zones (CZ's) and labor market areas (LMA's) were
developed because county boundaries are not adequate confines for
an area's economy. A local economy and its labor market are bounded
not by the nearest county line, but by interrelationships between
buyers and sellers of labor. If we are to understand the diversity
of nonmetro America we need a geographic standard capturing
variations in local economic and labor force activities. The
central objective of CZ's and LMA's was to develop such a
geographic unit that better captures the economic and social
diversity of nonmetro areas.
For 1990, 741 commuting zones were delineated for all U.S.
counties and county equivalents. These commuting zones were
developed without regard to a minimum population threshold and are
intended to be a spatial measure of the local labor market. Where
necessary, the commuting zones were aggregated into 394 labor
market areas that met the Bureau of the Census's criterion of a
100,000 population minimum. This was done to acquire a special 1990
Census Public Use Microdata Sample (PUMS-L) that identifies labor
market areas in which individuals work. The commuting zones and
labor market areas were also classified by the population of the
largest city within each of them.
In 2000, there were 709 commuting zones delineated for the U.S.
using the same methodology as was used in the previous decades.
Labor market areas were not estimated for 2000, because many
researchers found them to be too large and not as useful as the
commuting zones.
Nonmetro Commuting Zones and Labor Market Areas Classified by
Size
- Small Town/Rural: Population of largest place in the commuting
zone/labor market area was less than 5,000 in 1990.
- Small Urban Center: Population of largest place ranged from
5,000 to less than 20,000 in 1990.
- Large Urban Center: Population of largest place was at least
20,000 in 1990.
Metro Commuting Zones and Labor Market Areas
- Small Metro Center: Population of the largest MSA in the
commuting zone/labor market area was less than 250,000 in
1990.
- Medium Metro Center: Population of largest MSA was at least
250,000 but less than 1,000,000 in 1990.
- Major Metro Center: Population of largest MSA was 1,000,000 or
greater in 1990, or commuting zone/labor market area is part of a
Consolidated Metropolitan Statistical Area.