Related Sections
http://proximityone.com/metros.htm
http://proximityone.com/metros2013.htm
Metropolitan Areas
Metropolitan Statistical Area/Micropolitan Statistical Area (CBSA) National Shapefile -- tl_2013_us_cbsa
Metropolitan Division National Shapefile -- tl_2013_us_metdiv
Combined Statistical Area (CSA) National Shapefile -- tl_2013_us_csa
Combined New England City and Town Area (CNECTA) National Shapefile -- tl_2013_us_cnecta
New England City and Town Area (NECTA) National Shapefile -- tl_2013_us_necta
New England City and Town Area (NECTA) Division National Shapefile -- tl_2013_us_nectadiv
On February 28, 2013, the U.S. Office of Management and Budget (OMB) announced the definition of metropolitan statistical areas and micropolitan statistical areas based on the official standards that were published in the Federal Register on June 28, 2010. These standards were developed by the interagency Metropolitan Area Standards Review Committee to provide a nationally consistent set of geographic entities for the United States and Puerto Rico. No metropolitan or micropolitan areas are defined in the Island areas.
The general concept of a metropolitan statistical area or micropolitan statistical area is that of a core area containing a substantial population nucleus, together with adjacent communities having a high degree of economic and social integration with that core. The term “core based statistical area” (CBSA) became effective in 2000 and refers collectively to metropolitan statistical areas and micropolitan statistical areas.
The standards provide that each CBSA must contain at least one urban area of 10,000 or more population. Each metropolitan statistical area must have at least one urbanized area of 50,000 or more inhabitants. Each micropolitan statistical area must have at least one urban cluster of at least 10,000 but less than 50,000 population size. The categorization of CBSAs as either a metropolitan statistical area or a micropolitan statistical area is based on the population in the most populous (or dominant) core, not the total CBSA population or the total population of all (multiple) cores within the CBSA. If specified criteria are met, a metropolitan statistical area containing a single core with a population of 2.5 million or more may be subdivided to form smaller groupings of counties referred to as metropolitan divisions.
Under the standards, the county (or counties) or equivalent entity (or entities) in which at least 50 percent of the population resides within urban areas of 10,000 or more population, or that contain at least 5,000 people residing within a single urban area of 10,000 or more population, is identified as a central county (counties). Additional outlying counties are included in the CBSA if they meet specified requirements of commuting to or from the central counties. Counties or equivalent entities form the building blocks for metropolitan and micropolitan statistical areas throughout the United States and Puerto Rico.
In New England (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont), the OMB has defined an alternative county subdivision- (generally city- and town-) based definition of CBSAs known as New England city and town areas (NECTAs). NECTAs are defined using the same criteria as metropolitan statistical areas and micropolitan statistical areas and are identified as either metropolitan or micropolitan, based, respectively, on the presence of either an urbanized area of 50,000 or more population or an urban cluster of at least 10,000 and less than 50,000 population. A NECTA containing a single core with a population of at least 2.5 million may be subdivided to form smaller groupings of cities and towns referred to as NECTA divisions.
The metropolitan and micropolitan statistical area boundaries, names, and codes appearing in the 2013 TIGER/Line Shapefiles are the updates to metropolitan and micropolitan statistical areas as of February 2013, announced by the OMB on February 28, 2013.
Combined New England City and Town Areas (CNECTAs) consist of two or more adjacent New England city and town areas (NECTAs) that have significant employment interchanges. The NECTAs that combine to create a CNECTA retain separate identities within the larger combined statistical areas. Because CNECTAs represent groupings of NECTAs they should not be ranked or compared with individual NECTAs.
Combined Statistical Areas (CSAs) consist of two or more adjacent CBSAs that have significant employment interchanges. The CBSAs that combine to create a CSA retain separate identities within the larger CSAs. Because CSAs represent groupings of metropolitan and micropolitan statistical areas, they should not be ranked or compared with individual metropolitan and micropolitan statistical areas.
Core Based Statistical Areas (CBSAs) consist of the county or counties or equivalent entities associated with at least one core (urbanized area or urban cluster) of at least 10,000 population, plus adjacent counties having a high degree of social and economic integration with the core as measured through commuting ties with the counties containing the core. A CBSA receives a category based on the population of the largest urban area within the CBSA. Categories of CBSAs are: metropolitan statistical areas, based on urbanized areas of 50,000 or more population, and micropolitan statistical areas, based on urban clusters of at least 10,000 population but less than 50,000 population.
Metropolitan Divisions are created when a metropolitan statistical area containing a single core with a population of at least 2.5 million is subdivided to form smaller groupings of counties or equivalent entities. Not all metropolitan statistical areas with urbanized areas of this size will contain metropolitan divisions. A metropolitan division consists of one or more main counties that represent an employment center or centers, plus adjacent counties associated with the main county or counties through commuting ties. Because metropolitan divisions represent subdivisions of larger metropolitan statistical areas, it is not appropriate to rank or compare metropolitan divisions with metropolitan and micropolitan statistical areas.
Metropolitan Statistical Areas are CBSAs associated with at least one urbanized area that has a population of at least 50,000. The metropolitan statistical area comprises the central county or counties or equivalent entities containing the core, plus adjacent outlying counties having a high degree of social and economic integration with the central county through commuting.
Micropolitan Statistical Areas are CBSAs associated with at least one urban cluster that has a population of at least 10,000, but less than 50,000. The micropolitan statistical area comprises the central county or counties or equivalent entities containing the core, plus adjacent outlying counties having a high degree of social and economic integration with the central county as measured through commuting.
New England City and Town Areas (NECTAs) are an alternative set of geographic entities, similar in concept to the county-based CBSAs, that OMB defines in New England based on county subdivisions—usually cities and towns. NECTAs receive a category in a manner similar to CBSAs and are referred to as metropolitan NECTAs or micropolitan NECTAs.
New England City and Town Area (NECTA) Divisions are created when a NECTA containing a single core with a population of at least 2.5 million is to form smaller groupings of cities and towns. A NECTA division consists of a main city or town that represents an employment center, plus adjacent cities and towns associated with the main city or town through commuting ties. Each NECTA division must contain a total population of 100,000 or more. Because NECTA divisions represent subdivisions of larger NECTAs, it is not appropriate to rank or compare NECTA divisions with NECTAs. It would be appropriate to rank and compare NECTA divisions.
OMB's standards provide for the identification of one or more principal cities within each Metropolitan Statistical Area, Micropolitan Statistical Area, and NECTA. Principal cities encompass both incorporated places and census designated places (CDPs). In addition to identifying the more significant places in each Metropolitan and Micropolitan Statistical Area or NECTA in terms of population and employment, principal cities are also used in titling Metropolitan and Micropolitan Statistical Areas, Metropolitan Divisions, Combined Statistical Areas, NECTAs, NECTA Divisions, and Combined NECTAs. A principal city may be only a part of a place if a portion of that place is outside of the Metropolitan Statistical Area, Micropolitan Statistical Area, or NECTA for which the place is principal.
Core Based Statistical Area Codes—The metropolitan statistical areas, micropolitan statistical areas, New England city and town areas (NECTAs), metropolitan divisions, and New England city and town area divisions are identified using a 5-digit numeric code. The codes for metropolitan and micropolitan statistical areas and metropolitan divisions are assigned in alphabetical order by area title and fall within the 10000 to 59999 range. Metropolitan divisions are distinguished by a 5-digit code ending in "4". NECTA and NECTA division codes fall within the 70000 to 79999 range and are assigned in alphabetical order by area title. NECTA divisions are distinguished by a 5-digit code ending in "4". The combined statistical areas and combined New England city and town areas are identified using a 3-digit numeric code. Combined statistical area codes fall within the 100 to 599 range. Combined NECTA codes fall within the 700 to 799 range. Since CBSA codes are defined nationally, no additional codes are required to provide a unique entity identifier. Since lower level divisions nest within CBSA and CBSAs nest within combined areas, the higher level codes exist in the record layouts for the subordinate entity types.