Geographic Concepts
The Local Area Unemployment Statistics (LAUS) program provides
estimates for the following geographic areas:
- census regions and divisions;
- states, the District of Columbia, and Puerto Rico;
- federal statistical areas—metropolitan areas, metropolitan divisions,
micropolitan areas, and combined areas;
- small labor market areas;
- counties and county equivalents;
- cities of 25,000 population or more;
- all cities and towns in New England, regardless of population; and
- 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
247 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:
- 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.
- 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.
- 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.
- 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: September 25, 2008