cbsa

The United States Core Based Statistical Areas (CBSA) Boundaries data set contains the boundaries for metropolitan and micropolitan statistical areas in the United States.  The data set contains information on location, identification, and size.  The database includes metropolitan and micropolitan boundaries within all 50 states, the District of Columbia, and Puerto Rico.

Combined statistical areas are groupings of adjacent metropolitan and/or micropolitan statistical areas that have social and economic ties as measured by commuting to work, but at lower levels than are found among counties within individual metropolitan and micropolitan statistical areas. Combined statistical areas can be characterized as representing larger regions that reflect broader social and economic interactions, such as wholesaling, commodity distribution, and weekend recreation activities, and are likely to be of considerable interest to regional authorities and the private sector. 

Each metropolitan or micropolitan statistical area consists 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. Metropolitan statistical areas contain at least one U.S. Census Bureau-defined urbanized area of 50,000 or more population; micropolitan statistical areas contain at least one Census Bureau-defined urban cluster of at least 10,000 and less than 50,000 population. If specified criteria are met, a metropolitan statistical area containing a single urbanized area with a population of 2.5 million or more may be subdivided into metropolitan divisions, which function as distinct social and economic areas within the larger metropolitan statistical area.

The data provide users with information about the locations, and names of CBSAs primarily for national planning applications.

Metropolitan and micropolitan statistical areas (referred to generically as "core based statistical areas" or CBSAs) are statistical geographic areas defined by the federal Office of Management and Budget (OMB), following a set of official standards published in the Federal Register. To meet the needs of various users for standard units at various geographic scales, OMB's standards provide for a flexible framework of area definitions that includes, in addition to metropolitan and micropolitan statistical areas, metropolitan divisions, combined statistical areas, New England city and town areas (NECTAs), NECTA divisions, and combined NECTAs. Documentation of the metropolitan and micropolitan statistical area standards and how they are applied is available on the Census Bureau's website or from the Population Distribution Branch, Population Division, U.S. Census Bureau, Washington, DC 20233-8800, telephone (301) 763-2419.

The CBSA database was compiled from TIGER/Line data with a corresponding positional accuracy of +/- 80m for the contiguous 48 States plus Washington D.C. and Hawaii.  TIGER/Line files for Puerto Rico and Alaska are at a scale of 1:125,000.  The shorelines for the 23 coastal states were created using 1:250,000 NOS digital data which has a positional accuracy of +/- 200m.  Thus, all internal political boundaries have a higher accuracy than do the coastal definitions with the exception of Puerto Rico and Alaska.