Measuring Rurality: New Definitions in 2003

Overview What is Rural? Metro/Nonmetro Definitions in 2003 2004 County Typology Codes Commuting Zones and Labor Market Areas Rural-Urban Continuum Codes Urban Influence Codes Data Options for Rural Research Recommended Readings Recommended Data Related Links

Rural America At A Glance, 2008 Edition

In June 2003, the OMB released the Census 2000 version of metropolitan (metro) and nonmetropolitan (nonmetro) areas, a classification system often used to define urban and rural America. In this most recent update, nonmetro America comprises 2,052 counties, contains 75 percent of the Nation's land, and is home to 17 percent (49 million) of the U.S. population. The new version classifies 298 formerly nonmetro counties (10.3 million residents) as metro; 45 metro counties (3 million people) were reclassified as nonmetro. Thus, the new set of nonmetro counties contains a net of 7.3 million fewer residents than the former (1993) set based on the 1990 census.

This latest reclassification reflects not only a decade of urban growth and restructuring, but also extensive modification of the rules governing metro and nonmetro status. OMB made far-reaching changes, simplifying criteria and adding a new micropolitan area classification. The new category subdivides previously undifferentiated nonmetro territory into two distinct types of counties—micropolitan and noncore, thus providing a window on the diversity found in nonmetro America.

Metro areas were previously defined to include central counties with one or more cities of at least 50,000 residents or with an urbanized area of 50,000 or more and total area population of at least 100,000. Outlying counties were included if they were both economically tied to the central counties, as measured by daily commuting, and they displayed a level of "metropolitan character" based on population density, urbanization, and population growth. A county with high "metropolitan character" would be included with as little as 15 percent of its workers commuting. A county low in such attributes would be regarded as nonmetro no matter how high the commuting linkage was to the central county or counties.

Under the new "core-based statistical area" system, metro areas are defined for all urbanized areas regardless of total area population. In addition, inclusion as an outlying county is based on a single commuting threshold of 25 percent with no "metropolitan character" requirement. Streamlining the criteria in this manner decreases the population covered by metro areas by approximately 2 million residents, but actual expansion of metro territory during the last decade added 8 million persons. The net effect reduces the 2000 nonmetro population from 55 to 49 million persons.

The addition of 49 new metro areas mostly results from actual growth during the decade of nonmetro cities past the 50,000 urbanized area threshold. The addition of formerly nonmetro counties to the fringe of existing metro areas comes partly from relentless suburbanization and partly from rule changes, specifically the removal of the "metropolitan character" requirement. The reclassification of 45 metro counties to nonmetro status is almost entirely a result of rule changes, particularly the increase in the commuting level required for inclusion as an outlying metro county. All but 4 of these new nonmetro counties became part of a micropolitan area.

At the same time that OMB changed its metro definitions, the Census Bureau modified the way in which it measures rural and urban outside of urbanized areas. The basic concept remains intact, namely that rural includes open country and small settlements of less than 2,500 persons. However, there are many small towns and cities that have adjoining towns or suburbs, both incorporated and unincorporated aggregations. The Bureau has defined such urban clusters regardless of political boundaries. For example, a small town of 2,000 people with an adjacent densely settled suburb of 800 people would be designated as an urban cluster with a population of 2,800. Under 1990 procedures there would be no combination and the population would remain rural.

Conversely, the Bureau identified rural parts of incorporated towns whose city limits are very broad and include some thinly settled territory. Thus, if a town of 5,000 people has 500 residents living in thinly settled portions, the 500 are classified as rural and the urban population would be just 4,500.

The introduction of urban clusters, along with adjustments to the criteria defining urbanized areas, caused considerable shifts in rural geography and population. The Bureau estimates that a net of about 5 million people may have been added to the urban population by the new procedures. Precise separation of rule-based shifts from actual trends of population deconcentration during the 1990s is difficult. Without rule changes, rural areas likely would have increased by around 2 million people between 1990 and 2000. Instead, the rural population declined from 62 to 59 million.