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. 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.

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. 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.