There are at least three major classification systems used by Federal agencies to classify the urbanicity of particular geographic or governmental units. The choice of which classification system to use is often determined by the desired outcome or the level of geographic aggregation that is required. All three systems involve determinations about the geographic location of the particular government or geographic entity (within or outside a Metropolitan and Micropolitan Statistical Areas (collectively called Core Based Statistical Areas) (CBSA)), and two of the three involve an additional typology based on population size and density.
In the Federal Register published December 27, 2000, the Office of Management and Budget (OMB) announced the Standards for Defining Metropolitan and Micropolitan Statistical Areas. These new standards replace and supersede the 1990 standards for defining Metropolitan Areas. OMB announced definitions of areas based on the new standards and Census 2000 data in June 2003. Click this link to view OMB's Standards for Defining Metropolitan and Micropolitan Statistical Areas (253 KB) and plain text version or for the 2003 OMB's Revised Definitions of Metropolitan Statistical Areas bulletin.
Please click here for help viewing PDF files.
A brief description of each classification system, along with data produced under each system, is presented below:
In the early 1970s, the Department of Agriculture, Economic Research Service (ERS), found a need for a classification of counties into various degrees of urbanicity. The resultant system, officially known as the ERS Rural-Urban Continuum Codes, is most often referred to as the Beale codes, after its creator, Dr. Calvin Beale. The Beale codes are calculated by examining the size of a county and its proximity to a metropolitan area. According to an April 2004 description by the Department of Agriculture:
"Rural-Urban Continuum Codes form a classification scheme that distinguishes metropolitan (metro) counties by the population size of their metro area, and nonmetropolitan (nonmetro) counties by degree of urbanization and adjacency to a metro area or areas. The metro and nonmetro categories have been subdivided into three metro and six nonmetro groupings, resulting in a nine-part county codification. The codes allow researchers working with county data to break such data into finer residential groups beyond a simple metro-nonmetro dichotomy, particularly for the analysis of trends in nonmetro areas that may be related to degree of rurality and metro proximity."
More detailed information about this coding system may be found at: http://www.ers.usda.gov/briefing/rurality/RuralUrbCon/
Use of the Beale codes for school districts requires a determination of the county location of the superintendent of the school system and the assignment of the code for that county to the school system. Clearly the classification of all school systems within a county is the same regardless of the size of the county. Also, classification is based on the physical location of the superintendent's office, which may be problematic for districts whose boundaries cross county lines. There may also be problems when the address of the superintendent is a post office box or other centrally located postal system that does not coincide with the geographic location of the district.
The second classification system, the Metro Status codes, was developed by the Office of Management and Budget and used by the Census Bureau. This system determines the location of the superintendent and assigns a 1 if that physical location is within the central city of a Core Based Statistical Area (CBSA), a 2 if the physical location is within a CBSA, but not in the central city, and a 3 of the location is outside a CBSA. Again, as with the Beale codes, there is the possibility of problems for districts that cross county boundaries or use central postal systems. In addition, there is the possibility that a district outside a CBSA may not be rural. That is, no sub-category exists to further delineate the code 3s into rural and non-rural.
For more detailed information about the Metropolitan Statistical codes, click here: http://www.census.gov/population/www/estimates/aboutmetro.html
The Locale codes were developed by NCES in the 1990s (and revised in 2002) for general description, sampling, and other statistical purposes. This coding system is based on both the proximity to metropolitan areas and on population size and density. As a further aid to users, these codes are assigned based on the addresses of the individual schools and are assigned at the school level. Thus, it is possible to identify areas within school districts as being different types of localities.
In order to determine the Locale code of a school district, it is necessary to determine the sums of enrollment for the various Locale codes within the district, and assign the district the Locale code of the plurality of students. Thus, it is not necessary for a majority of a school district's students to be in any one type of locality in order for the district to be classified as having that particular Locale code.
There is a continuing need for information at the school district level to meet the needs of policy makers, researchers, and the general public. Locale codes are based on the specific conditions of schools and refer to very small geographic areas and circumstances, such as population density and size, which are most likely to be homogeneous in such small areas. Thus, the Locale codes would generally provide the most accurate characterization of the type of community that students live in. However, when the unit of analysis is the school district, the use of the plurality method of assignment of Locale codes to the entire school district results in less precise results.
NCES has not used the Beale codes, even though they are the most widely known of these three codes. While the Beale codes contain categories similar to the Locale codes, they do not specifically identify small towns. In addition, the Beale codes are a county-wide determination, often forcing many districts of various urbanicity classifications into one category.
The Metro Status codes do not have the specificity to determine an exact definition of rural. Nevertheless, they are used in some analyses, especially those using the Current Population Survey or other similar sample data. The Current Population Survey is produced in a joint project between the Bureau of Labor Statistics and Bureau of the Census.