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. metropolitan statistical areas and primary metropolitan statistical areas,
4. non-metropolitan labor market areas,
5. counties and county equivalents,
6. cities of 25,000 population or more,
7. cities, towns, and unorganized areas in New England, and
8. parts of cities listed in (6) above which cross county boundaries.

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.

Metropolitan Areas

Standard definitions of metropolitan areas (MAs) for Federal statistical purposes are established under the auspices of the Office of Management and Budget (OMB). Revisions to these definitions occur each decade following the decennial census. A MA is currently defined as an area with (1) a city of 50,000 or more population or (2) a Census Bureau defined urbanized area of at least 50,000 in population provided that the component county/counties of the MA have a total population of at least 100,000. An outlying contiguous county is included in the geographic area of a MA if any one of six conditions relating to proportion of commutation, population density, proportion of residents in the urbanized area, proportion of the population considered to be urban, population growth between the last two decennial censuses, and number of residents in a central city is met.

MAs are classified as Metropolitan Statistical Areas (MSAs), Primary Metropolitan Statistical Areas (PMSAs), or Consolidated Metropolitan Statistical Areas (CMSAs). All MAs with a total population under one million are classified as MSAs. A MA with a total population of one million or more may qualify for designation as a CMSA comprised of two or more PMSAs, provided those individual PMSAs meet certain criteria for separate designation. There are two reasons for this two-tier approach in high population areas. First, without this system, some smaller metropolitan areas would be absorbed by larger, expanding neighbors and lose their identities. Second, some large metropolitan components have many of the characteristics of separate metropolitan areas and, at the same time, are also clearly part of a single metropolitan complex. The LAUS program publishes data at the MSA and PMSA levels. For a list of detailed standards used by the OMB for defining MAs, refer to the Federal Register, March 30, 1990, pages 12154-12160. A complete listing of the metropolitan areas, effective June 28, 1996, is contained in OMB Bulletin No. 96-08, "Revised Statistical Definitions for Metropolitan Areas (MAs) and Guidance on Uses of MA Definitions." (Note: The LAUS program usually incorporates the revised definitions with the publication of data for the January following the announcement.)

Labor Market Areas

Labor Market Areas (LMAs) are the basic substate geographic areas used for LAUS estimation. MSAs and PMSAs defined by OMB are designated as "major" LMAs for the LAUS program. All non-metropolitan areas within each state are grouped into "small" LMAs, usually consisting of one or more counties or county equivalents. Responsibility for the determination of small Labor Market Areas was transferred to BLS from the Employment and Training Administration (ETA) in 1982 with passage of the Job Training Partnership Act (JTPA). The LAUS program redefines small LMAs after each decennial census; the current designations are based on 1990 decennial census data.

Section 4(13) of the JTPA describes a LMA as "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, towns, and unorganized areas rather than counties.

The following designation criteria were used for determining LMAs following the 1990 decennial census.

Designation Criteria

1. If 15% (rounded to the nearest tenth of one percent) or more of the employed workers residing in a county commuted to another county, then the two counties were combined into one LMA.

2. After combining counties based on the "county-to-county" commuting criteria in (1) above, county-to-LMA flows were checked. If two or more counties had been combined into one LMA, an additional county was added if 15% or more of the employed workers residing in that additional county commuted to the combined LMA (not necessarily to any one county within the LMA). This procedure possibly required several iterations.

3. In the case of pre-existing multi-county LMAs, attempts were made to maintain historical continuity. Thus, if the commuting flows were only marginally below the new criteria (that is, within 1.645 standard errors of the 15%), the counties remained combined.

4. Small LMAs, as with MAs, were required to be contiguous. Counties were first combined based on the commutation criteria, and then potential multi-county LMAs were checked for contiguity. Noncontiguous portions of potential LMAs were considered separately. If the noncontiguous area contained more than one county, it was reevaluated using (1), (2), and (3) above. If the noncontiguous area was a single county, it was designated as a separate LMA.

5. In the New England States, due to the large number of small cities, towns, and unorganized areas, residual areas were added to contiguous multi-area LMAs based on commuting flows and/or other economic ties. That is, if after applying the commutation criteria, a city/town had been identified as an individual LMA, the state was able to recommend that the city/town be added to a contiguous multi-area LMA, especially if the city/town was extremely small.

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 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 part residing in each county.

Last modified: October 16, 2001

URL: http://www.bls.gov/LAU
Phone: (202) 691-6392
Fax: (202) 691-6459
LAUS data questions: lausinfo@bls.gov
Technical (web) questions: webmaster@bls.gov
Other comments: feedback@bls.gov