OFFICE OF MANAGEMENT AND BUDGET

STANDARDS FOR DEFINING METROPOLITAN AND MICROPOLITAN STATISTICAL AREAS

The Office of Management and Budget (OMB) has adopted new standards for defining Metropolitan and Micropolitan Statistical Areas. These new standards replace those adopted in 1990 for defining metropolitan areas. In adopting these new standards, OMB accepted many of the recommendations of the interagency Metropolitan Area Standards Review Committee (see Federal Register, August 22, 2000).

Background:

The Metropolitan Area program has provided standard statistical area definitions for 50 years. It sets a uniform set of geographical definitions for the Nation’s largest centers of population. The “Standard Metropolitan Areas” concept was used for the first time in the 1950 census reports. Since then it has been possible to compare data products with each subsequent census. Because of the usefulness of the data collected, requests were made to expand the program to include more geographical areas of the United States. The Micropolitan Statistical Area program is the response to these requests.

I: Concept and Uses

The general concept of a Metropolitan Statistical Area or a Micropolitan Statistical Area is that of an area containing a recognized population nucleus and adjacent communities that have a high degree of integration with the center. The primary purpose of both programs is to provide a nationally consistent system of definitions for collecting, tabulating, and publishing Federal statistics for an area. The success of the program can be measured by the broad use of the data in both issue discussions and in the development of public policy. The social and economic data produced are heavily used in both the public sector and also by private concerns.

Metropolitan and Micropolitan Statistical Areas, collectively called Core Based Statistical Areas (CBSAs), should be used primarily as a statistical collection and interpretation mechanism. They are not suited for non-statistical areas. They may not work as a means for program funding or for overall policy decision-making. For example, neither area equates to an urban-rural definition. Both contain rural and urban territory. Therefore, a program that seeks to help rural areas by concentrating only on non-CBSA counties may miss a large population of rural residents that resides in a portion of a CBSA county.

II: Evolution and Review of the Metropolitan Area Standards

Periodic reviews of the standards used to define the areas ensure their continued usefulness and relevance. OMB chartered the Metropolitan Area Standards Review Committee in the fall of 1998 to examine 1990 standards and make recommendations. The Review Committee included representatives from the Bureau of the Census, Bureau of Economic Analysis, Bureau of Labor Statistics, Bureau of Transportation Statistics, Economic Research Service of the Department of Agriculture, National Center for Health Statistics, and OMB as an ex officio member.

OMB presented the initial recommendations of the Review Committee in the October 20, 1999 Federal Register. This was followed by a final report on August 22, 2000 entitled “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.”

Decisions of the Committee are summarized below:

I. The Review Committee made specific recommendations on defining Metropolitan Areas and Micropolitan Areas within a Core Based Statistic Area (CBSA). The decision retains the current conceptual approach of defining Metropolitan Areas around concentrations of 50,000 or more population.

II. OMB accepted the Review Committee’s recommendation to use counties and equivalent entities as the geographic building blocks of the CBSAs throughout the United States. Cities and towns would be the building blocks in New England for defining New England City and Town Areas (NECTAs). Both of these decisions continue current practice. However, CBSAs will also be developed for New England based on county boundaries to maintain a uniform nationally consistent geographical building block.

III. The Census Bureau would continue to define urban areas of 50,000 or more population and urban clusters of 10,000 to 49,999 as the cores of CBSAs and to use their locations to determine central counties of CBSAs. Central counties must have at least 50 percent of their population in urban areas of at least 10,000 population or have within their boundaries a population of at least 5,000 located in a single urban area of at least 10,000 population.

IV. Journey to work data or commuting patterns would continue to be the basis of grouping counties together to form CBSAs (i.e., to qualify an outlying county). An outlying county would qualify if at least 25 percent of the employed residents work in the central county or at least 25 of the jobs in the outlying county are filled by workers from the central county. This figure represents an increase from the 15 percent minimum used in 1990. OMB increased the standard because cross county commuting is now more common than in1960 when the standards were developed.

V. Contiguous CBSAs would be merged to form a single CBSA when the central county or counties of one area qualify as outlying to the central county of another area. The same 25 percent threshold would be used.

VI. Principal cities would be identified in each Metropolitan or Micropolitan Statistical Area. The largest incorporated place of at least 10,000 would be recognized as the Principal City. In addition, other cities of at least 50,000 can also be identified as Principal Cities in the metropolitan area.

VII. Within Metropolitan Statistical Areas and NECTAs with at least one core of 2,5 million or more population, Divisions would be identified if they functioned as distinct areas.

VIII. Contiguous CBSAs would be combined when ties between them are less intense than in V, but still significant. Combinations could occur when the employment interchange measure was between 15 and 25 percent only if local opinion in the area favored the change. The merger would be automatic if the interchange equals or exceeds 25 percent.

IX. Metropolitan Divisions would be named using up to three Principal Cities or up to three counties if no Principal City is present. For NECTA divisions, if no Principal City is present, the name would be that of the largest minor civil division.

X. Only statistical rules would be used when defining Metropolitan and Micropolitan Statistical Areas.

XI. OMB would not define types of settlement, such as urban, suburban, rural and so forth, within the CBSA classification.

XII. Current Metropolitan Area definitions would not be automatically retained in defining new Metropolitan and Micropolitan Statistical Areas.

XIII. OMB would define new CBSAs between decennial censuses on the basis of Census Bureau population estimates and to update all existing CBSAs in 2008 using commuting data from the American Community Survey. The first areas to be designated by OMB using the new standards will be announced in 2003.

Standards for Defining Metropolitan and Micropolitan Statistical Areas

Summary:

1. Urban area of at least 50,000 population or a Census defined urban cluster of at least 10,000 population.

2. Central Counties have at least 50 percent of the population in urban areas of 10,000 population or have within their boundaries a population of at least 5,000 located in a single urban area of at least 10,000 population.

3. A county qualifies as an outlying county of a CBSA if (a) at least 25 percent of the employed residents of the county work in the central county or counties; or (b) at least 25 percent of the employment in the county is accounted for by workers who reside in the central county or counties of the CBSA.

4. Two adjacent CBSAs will merge to form one if the central county or counties of one CBSA qualify as outlying to the central county or counties of another CBSA.

5. Principal City (Cities) of a CBSA will include (a) the largest city with a population of at least 10,000 population; (b) any additional incorporated place or census designated place with a population of at least 250,000 or in which 100,000 or more people work; (c) any additional place of at least 50,000 in which the number of jobs exceeds the number of employed residents; and (d) any additional incorporated place with at least 10,000, but less than 50,000 population, and one-third the population size of the largest place, and in which the number of jobs meets or exceeds the number of employed residents.

6. All CBSAs are divided into Metropolitan Statistical Areas (population of 50,000 or more) or Micropolitan Statistical Areas (10,000 to 49,999).

7. Metropolitan areas of 2.5 million or more may be subdivided into Metropolitan Divisions. A county qualifies as a main county of a Metropolitan Division if 65 percent or more of its employed residents work in the county and the ratio of number of jobs to employed residents is at least .75. A secondary county has at least 50 percent of its residents working in the county and a job to employment ratio of at least .75.

8. Two adjacent CBSAs will form a Combined Statistical Area if the employment interchange between the two is 25 percent. If the interchange is at least 15 and less than 25 percent, CBSAs will be combined if local opinion supports it.

9. CBSAs will be titled based on the largest Principal City. If additional cities are listed, they will be listed in descending population size.

10. The Office of Management and Budget will define CBSAs based on Census 2000 data in 2003. Cities outside an existing CBSA that attain a population of 10,000 by special census or in estimates for two consecutive years will be designated as CBSAs of OMB. In 2008 OMB will review commuting patterns from the American Community Survey to update CBSA definitions.