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Metropolitan Statistical Areas and Delineations

A Metropolitan Statistical Area (MSA) is defined by the Office of Management and Budget (OMB) and is used by the Census Bureau and other federal government agencies for statistical purposes.  In the United States, the MSA is a geographical region with a relatively high population density at its core and close economic ties throughout the area. Such regions are neither legally incorporated as a city or town would be, nor are they legal administrative divisions like counties or separate entities such as States. As such, the precise definition of any given MSA can vary with the location. A typical metropolitan area is centered on a single large city that wields substantial influence over the region (e.g., Baltimore, Chicago or Atlanta). However, some metropolitan areas contain more than one large city with no single municipality holding a substantially dominant position (e.g., Dallas-Fort Worth, Norfolk-Virginia Beach (Hampton Roads), Riverside- San Bernardino (Inland Empire), or Minneapolis-Saint Paul.  

“A MSA’s geographic composition, or list of geographic components at a particular point in time, is referred to as its "delineation"." MSA’s are the result of the application of published standards to Census Bureau data. The standards for delineating the areas are reviewed and revised once every ten years, prior to each decennial census. Generally, the areas are delineated using the most recent set of standards following each decennial census. Between censuses, the delineations are updated to reflect Census Bureau population estimates. “Areas based on the 2010 standards and Census Bureau data were delineated in February of 2013, and updated in July of 2015.

The top 48 U.S. MSA’s represent more than half of the countries entire urban population and the trend will only accelerate as the agrarian sector of our economy becomes more industrialized and automated and by default, will become less populated. As this trend continues, more and more people will move to urban metropolitan areas. A majority of the U.S. population lives in incorporated places or cities, although these areas only make up a small fraction of the U.S. land area. The country is undeniably urban and the majority is counted by population, not by the amount of urban area. The population density in cities is more than 46 times higher than the territory outside of cities. The average population density for cities is 1,593.5 people per square mile, while the density outside of this area is only 34.6 people per square mile. Population density generally increases with city population size. The population density of cities with 1 million or more people is 7,192 people per square mile.

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