KEY TERMS

METROPOLITAN AND MICROPOLITAN AREAS

Census Designated Place: A statistical area that is equivalent to an incorporated place, consisting of a locally recognized, unincorporated concentration of population that is identified by name.

Central County: The county or counties of a Core Based Statistical Area containing a substantial portion of urbanized area or urban cluster or both, and to and from which commuting is measured to determine qualification of outlying counties.

Combined Statistical Area: A geographical area consisting of two or more adjacent Core Based Statistical Areas (CBSAs) with employment interchange of at least 15 percent. Combination is automatic if the employment interchange is 25 percent and determined by local opinion if more than 15 but less than 25 percent.

Core: A densely settled concentration of population with an urbanized area of 50,000 or more population or an urban cluster of 10,000 to 49,999 population.

Core Based Statistical Area (CBSA): A geographical area consisting of a county or counties associated with at least one core, plus adjacent counties with a high level of integration as measured by commuting patterns.

Employment Interchange Measure: A measure of the ratio of employed residents in a smaller entity that work in the larger entity and the percent of employment in the smaller entity that is accounted for by worked who reside in the larger entity.

Geographical Building Block: The geographical unit, such as a county, that constitutes the basic component of the statistical area.

Main County: A county that acts as an employment center within a CBSA that has a core population of at least 2.5 million. Main counties serve as the basis for defining a metropolitan division.

Metropolitan Division: A county or counties within a CBSA that consists of one or more main/secondary counties that represent an employment center or centers, plus adjacent counties associated with the main county or counties through commuting ties.

Metropolitan Statistical Area: A CBSA associated with at least one urbanized area of at least 50,000 population. The central county plus adjacent counties with a high degree of integration comprise the area.

Micropolitan Statistical Area: A CBSA associated with at least one urban cluster with a population of at least 10,000. The central county plus adjacent counties with a high degree of integration comprise the area.

Outlying County: A county that qualifies for inclusion in the Core Based Statistical Area on the basis of commuting ties.

Outside Core Based Statistical Areas: Counties that do not qualify for inclusion in a CBSA.

Principal City: The largest city of a Core Based Statistical Area, plus additional cities that meet minimum standards.

Secondary County: A county that acts as an employment center within a CBSA with a population of at least 2.5 million.

Urban Area: The generic term used by the Census Bureau for urbanized area and urban clusters.

Urban Cluster: A central place and adjacent territory that together contain at least 2,500 people and an overall density of 1,000 per square mile. For CBSAs, only those urban clusters with a population of 10,000 or more are considered.

Urbanized Area: A central place and adjacent territory that contain at least 50,000 people and an overall density of 1,000 per square mile.