ANSI INCITS-454-2009 pdf download Codes for the Identification of Metropolitan and Micropolitan Statistical Areas and Related Statistical Areas of the United States and Puerto Rico
1. Scope and purpose This standard establishes a structure for the assignment of data codes by which to uniquely identify metropolitan and micropolitan statistical areas (generically referred to as “core-based statistical areas”) and related statistical areas (i.e., metropolitan divisions, combined statistical areas, New England city and town areas (NECTAs), NECTA divisions, and combined NECTAs) of the United States and Puerto Rico, for the purpose of information interchange among data processing systems.
2. Definitions and coverage Metropolitan and micropolitan statistical areas are statistical geographic areas consisting 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 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 1 0,000 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 areas within the larger metropolitan statistical area.
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.
New England city and town areas (NECTAs), NECTA divisions, and combined NECTAs provide a city- and town-based set of areas conceptually similar to the county-based metropolitan and micropolitan statistical areas, metropolitan divisions, and combined statistical areas