Revised Standards for Defining Metropolitan Areas in the 1990s

Part I. Overview

Part I gives the structure of this document. Part II describes the changes from the previous standards and the reasons for the changes. Part III gives the official metropolitan area standards for the 1990s. Part IV gives a list of definitions of key terms and guidelines used in the standards. The terms in Part IV are listed in alphabetical order.

In Part III, sections 1 through 7 contain the basic standards for defining metropolitan statistical areas in all States except the New England States. They specify standards for determining: how large a population nucleus must be to qualify as an MSA (section 1); the central county/counties of the MSA (section 2); additional outlying counties with sufficient metropolitan character and integration to the central county/counties to qualify for inclusion in the MSA (section 3); the central city or cities of each MSA (section 4); whether two adjacent MSAs qualify to be combined (section 5); four categories or levels of MSAs, based on the total population of each area (section 6); and the title of each MSA (section 7).

Sections 8 through 10 provide a framework for identifying PMSAs within an MSA of at least one million population. If such PMSAs are identified, the larger area of which they are components is designated a CMSA.

Sections 11 through 15 apply only to the New England States. In these States, metropolitan areas are composed of cities and towns rather than whole counties. Sections 11, 12, and 13 specify how New England MSAs are redefined and titled. Sections 14 and 15 show how CMSAs and PMSAs are defined and titled.

Section 16 sets forth the standards for updating definitions between decennial censuses.


Part II. Changes in the Standards for the 1990s

The metropolitan area standards for the 1990s generally reflect a continuity with those adopted for the 1980s, and they maintain the basic concepts originally developed in 1950. The substantive modifications of the standards are specified below. Some other modifications have been made that involve word changes but not substance.

  1. Effective April 1, 1990, the set of areas known as Metropolitan Statistical Areas (MSAs), Primary Metropolitan Statistical Areas (PMSAs), and Consolidated Metropolitan Statistical Areas (CMSAs) will be designated collectively as Metropolitan Areas (MAs). The reason for this change is to distinguish between the individual areas known as MSAs and the set of all areas.
  2. A small group of counties containing a portion of a city's urbanized area will now qualify as outlying, even though their population density is relatively low. This change allows the inclusion in metropolitan areas of entire urbanized areas.
  3. Counties included solely because they contain at least 2,500 population in a central city now will be assigned outlying county rather than central county status (section 3A(6)). This will ensure that additional outlying counties will not be designated solely because of commuting with a county including a small portion of the central city.
  4. The largest city, and other cities of at least 15,000 in a secondary noncontiguous urbanized area within a metropolitan statistical area, now may be identified as central cities, provided that the other requirements for central cities are met (sections 4E and 4F). This allows cities that perform as central cities in secondary noncontiguous urbanized areas to be designated as central cities.
  5. The employment criterion for inclusion in an area title is deleted; only the population criteria remain (section 7). This change was made because in 1980 only one area qualified based on employment.
  6. A place qualifying as a central city but with less than one-third the population of the largest city may now be included in the metropolitan statistical area title if h2ly supported by local opinion (section 7A(3)). Communities often have h2 views on the way their MSAs are titled. This change allows taking these views into account.
  7. The presence of a small portion (less than 2,500 population) of the largest city of a CMSA in a county no longer precludes consideration of that county as a PMSA (section 8B(4)). Such a small portion of a city does not alter the characteristics of the PMSA.
  8. We have added standards for intercensal updating of metropolitan areas (section 16). These standards existed separately, but we felt they should be incorporated into the published standards.
  9. Qualifying percentages and ratios are considered to one decimal and ratios on the basis of two decimals (in each case, one less decimal than previously) (Part IV). The previous standards implied a level of accuracy that was not justified.
  10. Several technical adjustments were made (Part IV). For example, localities in Puerto Rico officially known as aldeas in 1980, are now termed comunidades.

Part III. Official Standards for Metropolitan Areas.

Basic Standards. Sections 1 through 7 apply to all States except the six New England States, that is, Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. They also apply to Puerto Rico.1

Section 1. Population Size Requirements for Qualification

Each metropolitan statistical area must include:
  1. A city of 50,000 or more population, or2
  2. A Census Bureau defined urbanized area of at least 50,000 population, provided that the component county/counties of the metropolitan statistical area have a total population of at least 100,000.3

Section 2. Central Counties

The central county/counties of the MSA are:
  1. Those counties that include a central city (see section 4) of the MSA, or at least 50 percent of the population of such a city, provided the city is located in a qualifier urbanized area; and
  2. Those counties in which at least 50 percent of the population lives in the qualifier urbanized area(s).

Section 3. Outlying Counties

  1. An outlying county is included in an MSA if any one of the six following conditions is met:
    1. At least 50 percent of the employed workers residing in the county commute to the central county/counties, and either
      1. The population density of the county is at least 25 persons per square mile, or
      2. At least 10 percent, or at least 5,000, of the population lives in the qualifier urbanized area(s);
    2. From 40 to 50 percent of the employed workers commute to the central county/counties, and either
      1. The population density is at least 35 persons per square mile, or
      2. At least 10 percent, or at least 5,000, of the population lives in the qualifier urbanized area(s);
    3. 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:
      1. Population density is at least 35 persons per square mile,
      2. At least 35 percent of the population is urban,
      3. At least 10 percent, or at least 5,000, of the population lives in the qualifier urbanized area(s);
    4. 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:
      1. Population density is at least 60 persons per square mile,
      2. At least 35 percent of the population is urban,
      3. Population growth between the last two decennial censuses is at least 20 percent,
      4. At least 10 percent, or at least 5,000, of the population lives in the qualifier urbanized area(s);
    5. 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:
      1. At least 35 percent of the population is urban,
      2. Population growth between the last two decennial censuses is at least 20 percent,
      3. At least 10 percent, or at least 5,000, of the population lives in the qualifier urbanized area(s);
    6. At least 2,500 of the population lives in a central city of the MSA located in the qualifier urbanized area(s).5
  2. 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.
  3. 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.

Section 4. Central Cities

The central city/cities of the MSA are:
  1. The city with the largest population in the MSA;
  2. Each additional city with a population of at least 250,000 or with at least 100,000 persons working within its limits;
  3. Each additional city with a population of at least 25,000, an employment/residence ratio of at least 0.75, and at least 40 percent of its employed residents working in the city;
  4. Each city of 15,000 to 24,999 population that is at least one-third as large as the largest central city, has an employment/residence ratio of at least 0.75, and has at least 40 percent of its employed residents working in the city;
  5. The largest city in a secondary noncontiguous urbanized area, provided it has at least 15,000 population, an employment/residence ratio of at least 0.75, and has at least 40 percent of its employed residents working in the city;
  6. Each additional city in a secondary noncontiguous urbanized area that is at least one-third as large as the largest central city of that urbanized area, that has at least 15,000 population and an employment/residence ratio of at least 0.75, and that has at least 40 percent of its employed residents working in the city.

Section 5. Combining Adjacent Metropolitan Statistical Areas

Two adjacent MSAs defined by sections 1 through 4 are combined as a single MSA provided:

  1. The total population of the combination is at least one million, and:
    1. The commuting interchange between the two MSAs is equal to:
      1. At least 15 percent of the employed workers residing in the smaller MSA, or
      2. At least 10 percent of the employed workers residing in the smaller MSA, and
        1. The urbanized area of a central city of one MSA is contiguous with the urbanized area of a central city of the other MSA, or
        2. A central city in one MSA is included in the same urbanized area as a central city in the other MSA; and
    2. At least 60 percent of the population of each MSA is urban.
  2. The total population of the combination is less than one million and:
    1. Their largest central cities are within 25 miles of one another, or their urbanized areas are contiguous; and
    2. There is definite evidence that the two areas are closely integrated with each other economically and socially; and
    3. Local opinion in both areas supports the combination.

Section 6. Levels
  1. Each MSA defined by sections 1 through 5 is categorized in one of the following levels based on total population:
    Level A MSAs of 1 million or more;
    Level B MSAs of 250,000 to 999,999;
    Level C MSAs of 100,000 to 249,999; and
    Level D MSAs of less than 100,000.
  2. Areas assigned to Level B, C, or D are designated as MSAs. Areas assigned to Level A are not finally designated or titled until they have been reviewed under sections 8 and 9.
Section 7. Titles of Metropolitan Statistical Areas (MSAs)
  1. The title of an MSA assigned to Level B, C, or D includes the name of the largest central city, and up to two additional city names, as follows:
    1. The name of each additional city with a population of at least 250,000;
    2. The names of the additional cities qualified as central cities by section 4, provided each is at least one-third as large as the largest central city; and
    3. The names of other central cities (up to the maximum of two additional names) if local opinion supports the resulting title.
  2. An area title that includes the names of more than one city begins with the name of the largest city and lists the other cities in order of their population according to the most recent national census.6
  3. In addition to city names, the title contains the name of each State in which the MSA is located.

Standards for Primary and Consolidated Metropolitan Statistical Areas (PMSAs and CMSAs).

Sections 8 through 10 apply to Level A metropolitan statistical areas outside New England.

Section 8. Qualifications for Designation of Primary Metropolitan Statistical Areas (PMSAs)

Within a Level A MSA:
  1. Any county or group of counties that was designated an SMSA on January 1, 1980, will be designated a PMSA, unless local opinion does not support its continued separate designation for statistical purposes.
  2. Any additional county/counties for which local opinion h2ly supports separate designation will be considered for identification as a PMSA, provided one county is included that has:
    1. At least 100,000 population;
    2. At least 60 percent of its population urban;
    3. Less than 35 percent of its resident workers working outside the county; and
    4. Less than 2,500 population of the largest central city of the Level A MSA.
  3. A set of two or more contiguous counties for which local opinion h2ly supports separate designation, and that may include a county or counties that also could qualify as a PMSA under section 8B, also will be considered for designation as a PMSA, provided:
    1. Each county meets requirements (1), (2), and (4) of section 8B, and has less than 50 percent of its resident workers working outside the county;
    2. Each county in the set has a commuting interchange of at least 20 percent with the other counties in the set; and
    3. The set of two or more contiguous counties has less than 35 percent of its resident workers working outside its area.
  4. Each county in the interim Level A MSA, not included within a central core under sections 8A through C, is assigned to the contiguous PMSA to whose central core commuting is greatest, provided this commuting is:
    1. At least 15 percent of the county's resident workers;
    2. At least 5 percentage points higher than the commuting flow to any other PMSA central core that exceeds 15 percent; and
    3. Larger than the flow to the county containing the Level A MSA's largest central city.
  5. If a county has qualifying commuting ties to two or more PMSA central cores and the relevant values are within 5 percentage points of each other, local opinion is considered before the county is assigned to any PMSA.
  6. The interim PMSA definitions resulting from these procedures (including possible alternative definitions, where appropriate) are submitted to local opinion. Final definitions of PMSAs are made based on these standards, and a review of local opinion.
  7. If any primary metropolitan statistical area or areas have been recognized under sections 8A through F, the balance of the Level A metropolitan statistical area, which includes its largest central city, also is recognized as a primary metropolitan statistical area.7

Section 9. Levels and Titles of Primary Metropolitan Statistical Areas

  1. PMSAs are categorized in one of four levels according to total population, following the standards of Section 6A.
  2. PMSAs are titled in either of two ways:
    1. Using the names of up to three cities in the primary metropolitan statistical area that have qualified as central cities of the Level A MSA under section 4, following the standards of section 7 for selection and sequencing; or
    2. Using the names of up to three counties in the PMSA, sequenced in order from largest to smallest population.
  3. Local opinion on the most appropriate title will be considered.

Section 10. Designation and Titles of Consolidated Metropolitan Statistical Areas

  1. A Level A metropolitan statistical area in which two or more primary metropolitan statistical areas are identified by section 8 is designated a consolidated metropolitan statistical area. If no primary metropolitan statistical areas are defined, the Level A area remains a metropolitan statistical area, and is titled according to section 7.
  2. Consolidated metropolitan statistical areas are titled according to the following guidelines. Local opinion is always sought before determining the title of a consolidated metropolitan statistical area.
    1. The title of each area includes up to three names, the first of which is always the name of the largest central city in the area. A change in the first-named city in the title will not be made until both its population and the number of persons working within its limits are exceeded by the those of another city in the consolidated area.
    2. The preferred basis for determining the two remaining names is:
      1. The first city (or county) name that appears in the title of the remaining primary metropolitan statistical area with the largest total population; and
      2. The first city (or county) name that appears in the title of the primary metropolitan statistical area with the next largest total population.
    3. A regional designation may be substituted for the second and/or third names in the title if there is h2 local support and the proposed designation is unambiguous and suitable for inclusion in a national standard.


Standards for New England


In the six New England States of Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont, the cities and towns are administratively more important than the counties, and a wide range of data is compiled locally for these entities. Therefore, the cities and towns are the units used to define metropolitan areas in these States. The New England standards are based primarily on population density and commuting. As a basis for measuring commuting, a central core is first defined for each New England urbanized area.

In New England, there is an alternative county-based definition of MSAs known as the New England County Metropolitan Areas (NECMAs) (see Part IV).

Section 11. New England Central Cores

A central core is determined in each New England urbanized area through the definition of two zones.

  1. Zone A comprises:
    1. The largest city in the urbanized area;
    2. Each additional place in the urbanized area or in a contiguous urbanized area that qualifies as a central city under section 4, provided at least 15 percent of its resident employed workers work in the largest city in the urbanized area;8
    3. Each additional city or town at least 50 percent of whose population lives in the urbanized area or a contiguous urbanized area, provided at least 15 percent of its resident employed workers work in the largest city in the urbanized area plus any additional central cities qualified by section 11A(2).8
  2. Zone B comprises each city or town that has:
    1. At least 50 percent of its population living in the urbanized area or in a contiguous urbanized area; and
    2. At least 15 percent of its resident employed workers working in Zone A.8
  3. The central core comprises Zone A, Zone B, and any city or town that is physically surrounded by Zones A or B, except that cities or towns that are not contiguous with the main portion of the central core are not included.
  4. If a city or town qualifies under sections 11A through C for more than one central core, it is assigned to the core to which commuting is greatest, unless the relevant commuting percentages are within 5 points of each other, in which case local opinion as to the most appropriate assignment also is considered.

Section 12. Outlying Cities and Towns

  1. A city or town contiguous to a central core as defined by section 11 is included in its metropolitan statistical area if:
    1. It has a population density of at least 60 persons per square mile and at least 30 percent of its resident employed workers work in the central core; or
    2. It has a population density of at least 100 persons per square mile and at least 15 percent of the employed workers living in the city or town work in the central core.9
  2. If a city or town has the qualifying level of commuting to two different central cores, it is assigned to the metropolitan statistical area to which commuting is greatest, unless the relevant commuting percentages are within 5 points of each other, in which case local opinion as to the most appropriate assignment also is considered.
  3. If a city or town has the qualifying level of commuting to a central core, but has greater commuting to a nonmetropolitan city or town, it will not be assigned to any metropolitan statistical area unless the relevant commuting percentages are within 5 points of each other, in which case local opinion as to the most appropriate assignment will also be considered.

Section 13. Applicability of Basic Standards to New England Metropolitan Statistical Areas

  1. An area defined by sections 11 and 12 qualifies as a metropolitan statistical area if it contains a city of at least 50,000 population or has a total population of at least 75,000.10
  2. The area's central cities are determined according to the standards of section 4.
  3. Two adjacent New England metropolitan statistical areas are combined as a single metropolitan statistical area provided the conditions of section 5A are met. Section 5B is not applied in New England.
  4. Each New England metropolitan statistical area defined by sections 13A through C is categorized in one of the four levels specified in section 6A. Areas assigned to Level B, C, or D are designated as metropolitan statistical areas. Areas assigned to Level A are not finally designated until they have been reviewed under sections 14 and 15.
  5. New England metropolitan statistical areas are titled according to the standards of section 7.

Section 14. Qualification for Designation of Primary Metropolitan Statistical Areas (PMSAs)

The following are qualifications within a Level A metropolitan statistical area in New England:

  1. Any group of cities and towns that was recognized as a standard metropolitan statistical area on January 1, 1980, will be recognized as a primary metropolitan statistical area, unless local opinion does not support its continued separate recognition for statistical purposes.
  2. Any additional group of cities and/or towns for which local opinion h2ly supports separate recognition will be considered for designation as a primary metropolitan statistical area, if:
    1. The total population of the group is at least 75,000;
    2. It includes at least one city with a population of 15,000 or more, an employment/ residence ratio of at least 0.75, and at least 40 percent of its employed residents working in the city;
    3. It contains a core of communities, each of which has at least 50 percent of its population living in the urbanized area, and which together have less than 40 percent of their resident workers commuting to jobs outside the core; and
    4. Each community in the core also has:
      1. At least 5 percent of its resident workers working in the component core city identified in section 14B(2), or at least 10 percent working in the component core city or in places already qualified for this core; this percentage also must be greater than that to any other core or to the largest city of the Level A MSA; and
      2. At least 20 percent commuting interchange with the component core city together with other cities and towns already qualified for the core; this interchange also must be greater than with any other core or with the largest city of the Level A MSA.
  3. Contiguous component central cores may be merged as a single core if:
    1. Section 14B would qualify the component core city of one core for inclusion in the other core; and
    2. There is substantial local support for treating the two as a single core.
  4. Each city or town in the interim Level A MSA not included in a core under sections 14A through C is assigned to the contiguous PMSA to whose core its commuting is greatest, if:
    1. This commuting is at least 15 percent of the place's resident workers; and
    2. The commuting interchange with the core is greater than with the Level A MSA's largest city.
  5. If a city or town has qualifying commuting ties to two or more cores and the relevant values are within 5 percentage points of each other, local opinion is considered before the place is assigned to any PMSA.
  6. The interim PMSA definitions resulting from these procedures (including possible alternative definitions, where appropriate) are submitted to local opinion. Final definitions of PMSAs are made based on these standards, and a review of local opinion.
  7. If any primary metropolitan statistical area or areas have been recognized under sections 14A through F, the balance of the Level A metropolitan statistical area, which includes its largest city, also is recognized as a primary metropolitan statistical area.11

Section 15. Levels and Titles of Primary Metropolitan Statistical Areas and Consolidated Metropolitan Statistical Areas in New England

  1. New England primary metropolitan statistical areas are categorized in one of four levels according to total population, following section 6A.
  2. New England primary metropolitan statistical areas are titled using the names of up to three cities in the primary area that have qualified as central cities under section 4, following the standards of section 7 for selection and sequencing.
  3. Each Level A metropolitan statistical area in New England in which primary metropolitan statistical areas have been identified and supported by local opinion (according to section 14) is designated a consolidated metropolitan statistical area. Titles of New England consolidated metropolitan statistical areas are determined following the standards of section 10. A Level A metropolitan statistical area in which no primary metropolitan statistical areas have been defined is designated a metropolitan statistical area, and is titled according to the rules of section 7.

Section 16. Intercensal Metropolitan Area Changes

  1. Definitions.
    1. A Census Count is a special census conducted by the U.S. Bureau of the Census or a decennial census count updated to reflect annexations and boundary changes since the census.
    2. A Census Bureau Estimate is a population estimate issued by the U.S. Bureau of the Census for an intercensal year.
  2. Qualification for Designation of a Metropolitan Statistical Area. The qualifications for designation are as follows:
    1. A city reaches 50,000 population according to a Census Count or Census Bureau Estimate.
    2. A nonmetropolitan county containing an urbanized area (UA) defined by the Bureau of the Census at the most recent decennial census reaches 100,000 population according to a Census Count or Census Bureau Estimate. If the potential metropolitan statistical area centered on the urbanized area consists of two or more counties, their total population must reach 100,000. In New England, the cities and towns qualifying for the potential metropolitan statistical area must reach a total population of 75,000.
    3. The Census Bureau defines a new urbanized area based on a Census Count after the decennial census, and the potential metropolitan statistical area containing the urbanized area meets the population requirements of section 16.B(2).

      If a metropolitan statistical area is qualified intercensally by a Census Bureau Estimate, the qualification must be confirmed by the next decennial census, or the area is disqualified.

  3. Addition of Counties. Counties are not added to metropolitan statistical areas between censuses, except as follows:
    1. If a central city located in a qualifier urbanized area extends into a county not included in the metropolitan statistical area and the population of the portion of the city in the county reaches 2,500 according to a Census Count, then the county qualifies as an outlying county and is added to the metropolitan statistical area.
    2. If a metropolitan statistical area qualified intercensally under section 16B meets the requirements of section 5B for combination with a metropolitan statistical area already recognized, that combination may take place and thereby alter the definition of the existing metropolitan statistical area.
  4. Qualification for Designation of a Central City. A Census Count serves to qualify a central city (section 4) that has failed to qualify solely because its population was smaller than required - for example, it did not qualify as the largest city of the metropolitan statistical area (section 4A), or was below 250,000 (4B), below 25,000 (4C), or below 15,000 (4D-F). If qualification requires comparison with the population of another city, comparison is made with the latest available Census Bureau Estimate or Census Count of the population of the other city.
  5. Area Titles. The title of a metropolitan statistical area, primary metropolitan statistical area, or consolidated metropolitan statistical area may be altered to include the name of a place that has newly qualified as a central city on the basis described in section 16D, and that also meets the requirements of section 7. Such a change is made by adding the new name at the end of the existing title, but cannot be made if the title already contains three names. Names in area titles are not resequenced except on the basis of a decennial census.
  6. Other aspects of the metropolitan area definitions are not subject to change between censuses.


Part IV. General Procedures and Definitions

This part specifies certain important guidelines regarding the data and procedures used in implementing the standards. It also gives definitions for "city," "urbanized area," and other key terms.


General Procedures

Local Opinion. Local opinion is the reflection of the views of the public on specified matters relating to the application of the standards for defining metropolitan areas, obtained through the appropriate congressional delegation, and considered after the thresholds in the statistical standards have been met. Members of the congressional delegation will be urged to contact a wide range of groups in their communities, including business or other leaders, Chambers of Commerce, planning commissions, and local officials, to solicit comments on specified issues. OMB will consider all pertinent local opinion material on these matters in determining the final definition and title of the area. After a decision has been made on a particular matter, OMB will not again request local opinion on the same question until after the next national census.

Local opinion is considered for:
  1. Combining two adjacent metropolitan statistical areas (of less than one million population) whose central cities are within 25 miles of each other (section 5B).
  2. Metropolitan statistical area titles (section 7A(3)).
  3. Identifying primary metropolitan statistical areas within consolidated metropolitan statistical areas (sections 8 and 14).
  4. Titling primary metropolitan statistical areas (sections 9 and 15).
  5. Titling consolidated metropolitan statistical areas after identification of the largest city (sections 10 and 15).
  6. Assignment of a county or place that, based on commuting, is eligible for inclusion in more than one area (sections 3B, 8E, 11D, 12B and 12C, and 14E).
New England County Metropolitan Areas (NECMAs). The New England County Metropolitan Areas (NECMAs) provide an alternative to the official city-and- town-based metropolitan statistical areas in that region for the convenience of data users who desire a county-defined set of areas.

The NECMA for a metropolitan statistical area includes:
  1. The county containing the first-named city in the metropolitan statistical area title. In some cases, this county will contain the first-named city of one or more additional metropolitan statistical areas.
  2. Each other county which has at least half of its population in the metropolitan statistical area(s) whose first-named cities are in the county identified in step 1.

The NECMA for a consolidated metropolitan statistical area also is defined by the above rules, except that the New England portion of the consolidated metropolitan statistical area which includes New York City is used as the basis for defining a separate NECMA. No NECMAs are defined for individual primary metropolitan statistical areas.

The central cities of a NECMA are those cities in the NECMA that qualify as central cities of a metropolitan statistical area or consolidated metropolitan statistical area; some central cities may not be included in any NECMA title.

The title of the NECMA includes each city in the NECMA that is the first-named title city of a metropolitan area, in descending order of metropolitan statistical area (or primary metropolitan statistical area) total population. Other cities that appear in metropolitan area titles are included only if the resulting NECMA title would consist of no more than three names.

Levels for NECMAs are determined following section 6A of the official metropolitan area standards.

Percentages, Densities, and Ratios. Percentages and densities are computed to the nearest tenth (one decimal); ratios are computed to the nearest one hundredth (two decimals); and comparisons between them are made on that basis.

Populations. In general, the population data required by the standards are taken from the most recent national census. However, in certain situations either (1) the results of a special census taken by the Bureau of the Census, or (2) a population estimate published by the Bureau of the Census may be used to meet the requirements of the standards (section 16).

Review of Cutoffs and Values. OMB has promulgated these standards with the advice of the Federal Executive Committee on Metropolitan Areas, following an open period of public comment. After the 1990 decennial census data become available, the Federal Executive Committee will review the census data and their implications for the cutoffs and values used in the standards, and will report to OMB the results of its review.

Definitions of Key Terms

Central Core--The counties (or cities and towns in New England) that are eligible for initial delineation as primary metropolitan statistical areas because they meet specified population and commuting criteria.

City--The term "city" includes:

  1. Any place incorporated under the laws of its State as a city, village, borough (except in Alaska), or town (except in the New England States, New York, and Wisconsin). These comprise the category of incorporated places recognized in Bureau of the Census publications.
  2. In Hawaii, any place recognized as a census designated place by the Bureau of the Census in consultation with the State government; in Puerto Rico, any place recognized as a zona urbana or a comunidad by the Bureau of the Census in consultation with the Commonwealth government. (Hawaii and Puerto Rico do not have legally defined cities corresponding to those of most States.)
  3. Any township in Michigan, Minnesota, New Jersey, or Pennsylvania, and any town in the New England States, New York, or Wisconsin, at least 90 percent of whose population is classified by the Bureau of the Census as urban, provided it does not contain any part of a dependent incorporated place.

Commuting Interchange--The commuting interchange between two areas is the sum of the number of workers who live in either of the areas but work in the other.

County--For purposes of the standards, the term "county" includes county equivalents, such as parishes in Louisiana and boroughs and census areas (formerly census divisions) in Alaska. Certain States contain cities that are independent of any county; such independent cities in Maryland, Missouri, and Nevada are treated as county equivalents for purposes of the standards.

In Virginia, where most incorporated places of more than 15,000 are independent of counties, the standards usually regard each such city as included in the county from which it was originally formed, or primarily formed. In certain exceptional cases, the city itself is treated as a county equivalent, as follows:

  1. An independent city that has absorbed its parent county (Chesapeake, Hampton, Newport News, Suffolk, Virginia Beach); and
  2. An independent city associated with an urbanized area other than the one with which its parent county is primarily associated (for example, Colonial Heights).

A county included in a metropolitan area is either a central (section 2), or an outlying (section 3) county. An outlying county must be contiguous with a central county or with an outlying county that has already qualified for inclusion.

Employment/Residence Ratio--This ratio is computed by dividing the number of persons working in the city by the number of resident workers with place of work reported. (These items are taken from the most recent national census.) For example, a city with an equal number of jobs and working residents has an employment/residence ratio of 1.00.

Interim Area--An area that meets the requirements of sections 1 through 4, or sections 11 through 13, for metropolitan statistical area qualification, which needs to be further examined to determine: (1) if it qualifies for combination with any adjacent interim area, (2) its final level, based on population; and (3) if the area has 1 million or more population, the identification of primary metropolitan statistical areas, if any, and the preferences, expressed through local opinion, for consolidated or individual identity.

Largest Central City--The largest central city of a metropolitan area is the central city with the greatest population at the time of the initial metropolitan area designation. Once determined, the largest central city will not be replaced until both its population and the number of persons working within its limits are exceeded by those of another city in the area.

Outcommuting--The number (or percent) or workers living in a specified area, such as a city or a county, whose place of work is located outside that area.

Qualifier Urbanized Area--The qualifier urbanized area(s) for a metropolitan statistical area are:

  1. The urbanized area that resulted in qualification under section 1B or the urbanized area containing the city that resulted in qualification under section 1A.
  2. Any other urbanized area whose largest city is located in the same county as the largest city of the urbanized area identified in paragraph one above, or has a least 50 percent of its population in that county.

Secondary Noncontiguous Urbanized Area--An additional urbanized area within a metropolitan statistical area that has no common boundary of more than a mile with the main urbanized area around which the metropolitan statistical area is defined.

Standard Metropolitan Statistical Area--The term used from 1959 to 1983 to describe the statistical system of metropolitan areas, and the areas as individually defined. It was preceded by Standard Metropolitan Area (SMA) from 1950 to 1959, and superseded by Metropolitan Statistical Area in 1983. That term was adopted when the current system formally recognizing consolidated metropolitan statistical areas and their component primary metropolitan statistical areas was put in place. The term Metropolitan Area (MA) is used to describe the system and the areas collectively, but the individual areas will retain the MSA, CMSA, and PMSA nomenclature.

Urban--The Bureau of the Census classifies as urban:

(a) The population living in urbanized areas; plus
(b) The population in other incorporated or census designated places of at least 2,500 population at the most recent national census.

Urbanized Area--An area defined by the Bureau of the Census according to specific criteria, designed to include the densely settled area around a large place. The definition is based primarily on density rather than governmental unit boundaries. An urbanized area must have a total population of at least 50,000. (See qualifier urbanized area and secondary noncontiguous urbanized area).

END NOTES

  1. Those provisions of sections 1 through 7 that are applicable to New England are specified in the standards relating to New England (sections 11 through 15).

  2. An MSA designated on the basis of census data according to standards in effect at the time of designation will not be disqualified on the basis of lacking a city of at least 50,000 population.

  3. An MSA designated on the basis of census data according to standards in effect at the time of designation will not be disqualified on the basis of lacking and urbanized area of at least 50,000 or a total MSA population of at least 100,000.

  4. Also accepted as meeting this commuting requirement are:
    1. The number of persons working in the county who live in the central county/counties is equal to at least 15 percent of the number of employed workers living in the county; or
    2. The sum of the number of workers commuting to and from the central county/counties is equal to at least 20 percent of the number of employed workers living in the county.

  5. See section 4 for the standards for identifying central cities.

  6. The largest central city included in an existing metropolitan area title will not be resequenced in or displaced from that title until both its population and the number of persons working within its limits are exceeded by those of another city qualifying for the area title.

  7. If section 8G would result in the balance of the Level A metropolitan statistical area including a noncontiguous county, this county will be added to the contiguous primary metropolitan statistical area to which the county has the greatest commuting.

  8. Also accepted as meeting this commuting requirement are:
    1. The number of persons working in the subject city or town who live in the specified city or area is equal to at least 15 percent of the employed workers living in the subject city or town; or
    2. The sum of the number of workers commuting to and from the specified city or area is equal to at least 20 percent of the employed workers living in the subject city or town.

  9. This commuting requirement is also considered to have been met if:
    1. The number of persons working in the city or town who live in the central core is equal to at least 15 percent of the employed workers living in the city or town.
    2. The sum of the number of workers commuting to and from the central core is equal to at least 20 percent of the employed workers living in the city or town.

  10. A New England metropolitan statistical area designated on the basis of census data according to standards in effect at the time of designation will not be disqualified on the basis of lacking a total populaiton of at least 75,000.

  11. If section 14G results in the balance of the Level A metropolitan statistical area including a noncontiguous city or town, this place will be added to the contiguous primary metropolitan statistical area to which it has the greatest commuting.