New standards for defining concentrations of people were defined in 2000 by the Office of Management and Budget (OMB), which is part of the executive operations at the White House. "The general concept of a metropolitan area is that of an area containing a large population nucleus and adjacent communities that have a high degree of integration with that nucleus. The purpose of the metropolitan area standards is to provide nationally consistent definitions for collecting, tabulating, and publishing Federal statistics for a set of geographic areas." (Office of Management and Budget, Final Report and Recommendations From the Metropolitan Area Standards Review Committee to the Office of Management and Budget Concerning Changes to the Standards for Defining Metropolitan Areas, August 22, 2000)
The definition of “standard metropolitan areas” started in 1950 - see Statistical Programs and Standards for more context. The new definitions distinguish between micropolitan and metropolitan areas. As of June 2003, OMB defined the following areas for Virginia:
Standards for Defining Metropolitan Areas in the 1990's:
Section 3. Outlying Counties
- An outlying county is included in an MSA if any one of the six following conditions is met:
- At least 50 percent of the employed workers residing in the county commute to the central county/counties, and either
- The population density of the county is at least 25 persons per square mile, or
- At least 10 percent, or at least 5,000, of the population lives in the qualifier urbanized area(s);
- From 40 to 50 percent of the employed workers commute to the central county/counties, and either
- The population density is at least 35 persons per square mile, or
- At least 10 percent, or at least 5,000, of the population lives in the qualifier urbanized area(s);
- From 25 to 40 percent of the employed workers commute to the central county/counties and either the population density of the county is at least 50 persons per square mile, or any two of the following conditions exist:
- Population density is at least 35 persons per square mile,
- At least 35 percent of the population is urban,
- At least 10 percent, or at least 5,000, of the population lives in the qualifier urbanized area(s);
- From 15 to 25 percent of the employed workers commute to the central county/counties,4 the population density of the county is at least 50 persons per square mile, and any two of the following conditions also exist:
- Population density is at least 60 persons per square mile,
- At least 35 percent of the population is urban,
- Population growth between the last two decennial censuses is at least 20 percent,
- At least 10 percent, or at least 5,000, of the population lives in the qualifier urbanized area(s);
- From 15 to 25 percent of the employed workers commute to the central county/counties,4 the population density of the county is less than 50 persons per square mile, and any two of the following conditions also exist:
- At least 35 percent of the population is urban,
- Population growth between the last two decennial censuses is at least 20 percent,
- At least 10 percent, or at least 5,000, of the population lives in the qualifier urbanized area(s);
- At least 2,500 of the population lives in a central city of the MSA located in the qualifier urbanized area(s).5
- If a county qualifies on the basis of commuting to the central county/counties of two different MSAs, it is assigned to the area to which commuting is greatest, unless the relevant commuting percentages are within 5 points of each other, in which case local opinion about the most appropriate assignment will be considered.
- If a county qualifies as a central county under section 2 and also qualifies as an outlying county of another metropolitan area under section 3A on the basis of commuting to (or from) another central county, both counties become central counties of a single merged MSA.