United States metropolitan area

Metropolitan Statistical Areas (MSA) are large metropolitan areas of the United States as defined by the Office of Management and Budget. These areas are urban areas with a lot of people. An earlier version of the MSA was the "Standard Metropolitan Statistical Area" (SMSA). MSAs are used for official purposes. They are made up of counties and for some, county equivalents.

MSAs are created around a central urban area —an area with high population density. The counties within the urbanized area are known as the central counties of the MSA. Other nearby counties (known as outlying counties) can be a part of the MSA if these counties have strong social and economic connections to the central counties. Some areas within these outlying counties may actually be rural areas.

The population estimates for some metro areas are not always agreed upon. In some cases, different sources give numbers of people which differ by millions. The definitions used for the last U.S. Census differed from those for previous censuses. This makes it hard to compare official information from different dates. MSA boundaries do not stretch into Canada or Mexico. This can affect the number of people in several cities. For example, Detroit, Buffalo, El Paso and San Diego are often much larger than their MSA figures.

As of June 2003, there is now an additional classification, “Metropolitan Division.” The term metropolitan division is used for a county or group of counties that are a distinct employment area within a metropolitan statistical area that has at least 2.5 million people. A metropolitan division is a part of a larger metropolitan statistical area but it is often a distinct social, economic, and cultural area within the larger region.^[1]

1. ↑ Cite error: The named reference OMB_20-01 was used but no text was provided for refs named (see the help page).