Geographic Concepts

The Local Area Unemployment Statistics (LAUS) program provides estimates for the following geographic areas:

1. census regions and divisions;
2. states, the District of Columbia, and Puerto Rico;
3. federal statistical areas—metropolitan areas, metropolitan divisions, micropolitan areas, and combined areas;
4. small labor market areas;
5. counties and county equivalents;
6. cities of 25,000 population or more;
7. all cities and towns in New England, regardless of population; and
8. parts of cities listed in (6) above which cross county boundaries.

Standard geographic area definitions based on existing political divisions are used by the LAUS program to determine the specific areas for which estimates are generated. These same definitions are used by other Federal and state agencies, enabling comparison and tabulation of data across programs. Standardized definitions also increase the availability of input data for the LAUS program from other statistical or administrative programs.

Local geographic area designations vary across the United States. For example, parishes in Louisiana and boroughs in Alaska are equivalent to counties; independent cities in Maryland, Missouri, Nevada, and Virginia are considered equivalent to counties; and cities and towns in New England are generally used instead of counties, since counties in New England have little geopolitical significance.

Federal Statistical Areas

Standard definitions of areas for Federal statistical purposes are established under the auspices of the Office of Management and Budget (OMB). Revisions to the standards for defining areas occur each decade following the decennial census. Relative to the 1990s, the 2000-based standards resulted in the designation of 49 new metropolitan areas while revising the definitions of existing metropolitan areas, and also identified for the first time micropolitan areas. Additionally, the 2000 standards established two new sets of statistical areas—metropolitan divisions in the most populous metropolitan areas and combined areas. New England City and Town Areas (NECTAs) also were defined as an alternative to the county-based metropolitan and micropolitan areas in the six New England states; the LAUS program uses NECTAs rather than county-based areas for New England.

For the detailed standards used by OMB to redefine Federal statistical areas based on the 2000 Census, refer to Federal Register, December 27, 2000 (PDF 295 K). A complete listing of the updated areas appears in the attachment to OMB Bulletin No. 04-03, Update of Statistical Area Definitions and Additional Guidance on Their Uses, dated February 18, 2004.

As of OMB Bulletin No. 04-03, there are 367 metropolitan areas and 582 micropolitan areas in the United States. (These counts reflect the LAUS use of NECTAs in New England.) In addition, there are 8 metropolitan areas and 5 micropolitan areas in Puerto Rico. (Note that the LAUS program usually incorporates revised area definitions with the publication of data for the January following the announcement by OMB.)

For more information on the statistical areas defined by OMB, see New Statistical Area Designations Based on Census 2000.

Small Labor Market Areas

Labor market areas (LMAs) are the basic substate geographic areas used for LAUS estimation. The metropolitan and micropolitan areas defined by OMB are designated as "major" LMAs for the LAUS program. The balance of the Nation is grouped into "small" LMAs, consisting of one or more counties or county equivalents. The LAUS program redefines small LMAs after each decennial census; the current designations are based on Census 2000 data.

Broadly, a LMA is an economically integrated geographic area within which individuals can reside and find employment within a reasonable distance or can readily change employment without changing their place of residence. In addition, LMAs are nonoverlapping and geographically exhaustive. Since these designations are based on the degree of economic integration determined primarily by commutation flows without regard to state boundaries, some interstate LMAs exist. LMAs in New England are based on cities and towns rather than counties.

The following criteria were used for designate small LMAs following the 2000 Census:

1. Worker flows were examined, and counties combined into one small LMA if either or both of the following conditions were met:
   • At least 25 percent of the employed residents of one county commuted to work in another county
   • At least 25 percent of the employment (persons working) in one county were accounted for by workers commuting from another county.
2. Small LMAs, as is the case with metropolitan and micropolitan areas, are required to be contiguous. First, counties were combined based on the commutation criteria. Then, potential multi-county small LMAs were checked for contiguity. Noncontiguous portions of potential small LMAs were considered separately. If the noncontiguous area contained more than one county, it was reevaluated using (1) above. If the noncontiguous area consisted of a single county, it was designated as a separate small LMA.
3. Subsequent to the verification of contiguity described in (2) above, commuting flows between adjacent small LMAs were evaluated. Those areas for which the measures and thresholds specified in (1) above were met merged to form one small LMA. This procedure was limited to one iteration, as was the case for metropolitan and micropolitan area designation under the 2000-based standards.
4. For the New England city and town-based small LMAs, due to the very large number of small cities and towns, residual cities and towns were added to contiguous small LMAs based on commuting flows and/or other economic ties. If, after applying the commutation criteria, a city or town had been identified as an individual small LMA, the city or town may have been added to a contiguous small LMA, especially if the city or town was extremely small. The 18 cities and towns that were isolated between the metropolitan and/or micropolitan areas defined by the Office of Management and Budget were not defined within labor market areas.

Naming Conventions:  Single-county small LMA names typically include the full county name, followed by the state abbreviation, such as "Gillespie County, TX." Multi-county small LMA names consist of not more than three county names, in descending order of population, followed by the state abbreviation and the term "LMA," as in "Wise-Dickenson-Norton, VA LMA." Small LMAs with strong commuting ties to neighboring metropolitan or micropolitan areas were labeled "Adjacent LMAs."

In the case of interstate small LMAs, state abbreviations were sequenced according to the population sizes of the intrastate parts. That is, the state with the largest population share among the parts of the area was listed first, and so on, as in "Gogebic-Iron, MI-WI LMA."

Other Defined Areas

In addition to LAUS areas based on standard geographic classifications, several nonstandard areas are defined. Where LMAs cross state lines, estimates for each multi-county intrastate part of the interstate LMA are created as a necessity of the LAUS estimation procedures. Similarly, cities that are located in more than one county must have estimates created for the city parts in each county.

 

Last Modified Date: May 24, 2005