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 did not coincide with the Census Bureau’s metropolitan districts or the metropolitan definitions devised by other agencies or groups.

Limited acceptance of the MCD-based metropolitan districts and the proliferation of alternative approaches led the Federal Bureau of the Budget (later renamed the OMB) to conclude that a new approach was needed; the agency reached this conclusion as part of an evaluation of the needs of data users at the Federal and State level for metropolitan data. There also were concerns about the Census Bureau’s urban and rural classifications. As a result, two new statistical measures were adopted. First, the Bureau of the Budget, in cooperation with other Federal agencies, including the Census Bureau, established the standard metropolitan area (SMA) to define the metropolitan extent around large cities. Second, the Census Bureau developed the urbanized area (UA) definition to define the densely settled agglomerations around large cities (see, “The Urban and Rural Classifications”). The SMA provided a means of delimiting a functional zone of economic and social integration around a central place or places. The UA, in contrast, represented a measure of the extent of an urban agglomeration, including the built-up portion of a core place and the densely settled surrounding area. The Census Bureau implemented the programs that provided for defining SMAs and UAs for the 1950 census.

To maximize the range of statistical data that could be made available, the Bureau of the Budget decided to define SMAs in terms of whole counties. An exception was made for New England, where the subcounty units—the cities and towns—have always had local importance and a wide range of statistics available.

Since the new SMAs were to be used by all Federal statistical agencies, and not just for census purposes, the Bureau of the Budget assumed the task of defining them, acting with the advice of a newly formed interagency committee, currently known as the FECMA. The criteria used for defining MAs gradually evolved over the decades. In recent practice, the standards by which MAs are established and defined receive a comprehensive review Notes and References 13-4Metropolitan Areas