Metropolitan statistical area
In the United States, a metropolitan statistical area (MSA) is a geographical region with a relatively high population density at its core and close economic ties throughout the region.[1][2] Such regions are not legally incorporated as a city or town would be and are not legal administrative divisions like counties or separate entities such as states. As a result, sometimes the precise definition of a given metropolitan area will vary between sources. The statistical criteria for a standard metropolitan area were defined in 1949 and redefined as a metropolitan statistical area in 1983.[3]
A typical metropolitan area is polycentric and no longer monocentric due to suburbanization of employment and has a large historic core city, such as New York City or Chicago.[4] Some metropolitan areas include more than one large historic core city, including the Dallas–Fort Worth metroplex, Virginia Beach–Norfolk–Newport News (Hampton Roads), Riverside–San Bernardino (Inland Empire), and Minneapolis–Saint Paul (Twin Cities).
MSAs are defined by the Office of Management and Budget (OMB), which is part of the Executive Office of the President, and are used by the U.S. Census Bureau and other U.S. federal government agencies for statistical purposes.[5]
History[edit]
The Census Bureau created the metropolitan district for the 1910 census as a standardized classification for large urban centers and their surrounding areas. The original threshold for a metropolitan district was 200,000, but was lowered to 100,000 in 1930 and 50,000 in 1940.[12] The metropolitan districts were replaced by standard metropolitan areas (SMAs) in the 1950 census, which were defined by the Bureau of the Budget (now the Office of Management and Budget) and later renamed to standard metropolitan statistical areas (SMAs) in 1959.[12][13] The modern metropolitan statistical area was created in 1983 amid a large increase in the number of eligible markets, which grew from 172 in 1950 to 288 in 1980;[12][14] the core based statistical area (CBSA) was introduced in 2000 and defined in 2003 with a minimum population of 10,000 required for micropolitan areas and 50,000 for urban areas.[12][13]