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Technical Note

   This release presents labor force and unemployment data for census
regions and divisions, states, and selected substate areas from the
Local Area Unemployment Statistics (LAUS) program (tables 1 to 4).  Also
presented are nonfarm payroll employment estimates by state and major
industry sector from the Current Employment Statistics (CES) program
(tables 5 and 6).  The LAUS and CES programs are both federal-state
cooperative endeavors.

Labor force and unemployment--from the LAUS program

   Definitions.  The labor force and unemployment data are based on the
same concepts and definitions as those used for the official national
estimates obtained from the Current Population Survey (CPS), a sample
survey of households that is conducted for the Bureau of Labor Statis-
tics (BLS) by the U.S. Census Bureau.  The LAUS program measures employ-
ment and unemployment on a place-of-residence basis.  The universe for
each is the civilian noninstitutional population 16 years of age and
over.  Employed persons are those who did any work at all for pay or
profit in the reference week (the week including the 12th of the month)
or worked 15 hours or more without pay in a family business or farm,
plus those not working who had a job from which they were temporarily
absent, whether or not paid, for such reasons as labor-management dis-
pute, illness, or vacation.  Unemployed persons are those who were not
employed during the reference week (based on the definition above), had
actively looked for a job sometime in the 4-week period ending with the
reference week, and were currently available for work; persons on layoff
expecting recall need not be looking for work to be counted as unemployed.
The labor force is the sum of employed and unemployed persons.  The unem-
ployment rate is the number of unemployed as a percent of the labor force.

   Method of estimation.  Estimates for 48 of the 50 states, the District
of Columbia, the Los Angeles-Long Beach-Glendale metropolitan division, New
York City, and the balances of California and New York State are produced
using estimating equations based on regression techniques.  This method,
which underwent substantial enhancement at the beginning of 2005,utilizes
data from several sources, including the CPS, the CES, and state unemploy-
ment insurance (UI) programs.  Estimates for the state of California are
derived by summing the estimates for the Los Angeles-Long Beach-Glendale
metropolitan division and the balance of California.  Similarly, estimates
for New York State are derived by summing the estimates for New York City
and the balance of New York State.  Estimates for all nine census divi-
sions and the five additional substate areas contained in this release (the
Cleveland-Elyria-Mentor and Detroit-Warren-Livonia metropolitan areas and
the Chicago-Naperville-Joliet, Miami-Miami Beach-Kendall, and Seattle-
Bellevue-Everett metropolitan divisions) and their respective balances of
state are based on a similar regression approach that does not incorporate
CES or UI data.  Estimates for census regions are obtained by summing the
model-based estimates for the component divisions and then calculating the
unemployment rate.  Each month, census division estimates are controlled
to national totals; state estimates are then controlled to their respective
division totals.  Substate and balance-of-state estimates for the five areas
noted above are controlled to their respective state totals.  Estimates for
Puerto Rico are derived from a monthly household survey similar to the CPS.
A detailed description of the estimation procedures is available from BLS
upon request.

   Annual revisions.  Labor force and unemployment data for prior years
reflect adjustments made at the end of each year.  The adjusted estimates
reflect updated population data from the U.S. Census Bureau, any revisions
in the other data sources, and model reestimation.  In most years, histori-



                                   - 8 -



cal data for the most recent five years (both seasonally adjusted and not
seasonally adjusted) are revised near the beginning of each calendar year,
prior to or coincident with the release of January estimates.

   Seasonal adjustment.  Seasonal adjustment of modeled estimates of em-
ployment and unemployment levels is performed within the modeling procedure.
Series are decomposed into trend, seasonal, and irregular components and sur-
vey error.  This directly yields seasonally adjusted estimates for employment
and unemployment levels with reliability measures. Labor force levels and un-
employment rates are calculated from these two estimates.

   Area definitions.  The substate area data published in this release reflect
the standards and definitions established by the U.S. Office of Management and
Budget on November 20, 2007.  A detailed list of the geographic definitions is
available on the Internet at http://www.bls.gov/lau/lausmsa.htm.

Employment--from the CES program

   Definitions.  Employment data refer to persons on establishment payrolls who
receive pay for any part of the pay period that includes the 12th of the month.
Persons are counted at their place of work rather than at their place of resi-
dence; those appearing on more than one payroll are counted on each payroll.  In-
dustries are classified on the basis of their principal activity in accordance
with the 2007 version of the North American Industry Classification System.

   Method of estimation.  The employment data are estimated using a "link rela-
tive" technique in which a ratio (link relative) of current-month employment to
that of the previous month is computed from a sample of establishments reporting
for both months.  The estimates of employment for the current month are obtained
by multiplying the estimates for the previous month by these ratios.  Small-do-
main models are used as the official estimators for the approximately 39 percent
of CES published series which have insufficient sample for direct sample-based
estimates.

   Annual revisions.  Employment estimates are adjusted annually to a complete
count of jobs, called benchmarks, derived principally from tax reports that are
submitted by employers who are covered under state unemployment insurance (UI)
laws.  The benchmark information is used to adjust the monthly estimates between
the new benchmark and the preceding one and also to establish the level of em-
ployment for the new benchmark month.  Thus, the benchmarking process establishes
the level of employment, and the sample is used to measure the month-to-month
changes in the level for the subsequent months.

   Seasonal adjustment.  Payroll employment data are seasonally adjusted at the
statewide supersector level.  In some states, the seasonally adjusted payroll em-
ployment total is computed by aggregating the independently adjusted super-sector
series.  In other states, the seasonally adjusted payroll employment total is in-
dependently adjusted.  Revisions of historical data for the most recent 5 years
are made once a year, coincident with annual benchmark adjustments.

   Caution on aggregating state data.  State estimation procedures are designed
to produce accurate data for each individual state.  BLS independently develops
a national employment series; state estimates are not forced to sum to national
totals.  Because each state series is subject to larger sampling and nonsampling
errors than the national series, summing them cumulates individual state level
errors and can cause significant distortions at an aggregate level.  Due to these
statistical limitations, BLS does not compile a "sum-of-states" employment series,
and cautions users that such a series is subject to a relatively large and vola-
tile error structure.



                                   - 9 -



Reliability of the estimates

   The estimates presented in this release are based on sample surveys, adminis-
trative data, and modeling and, thus, are subject to sampling and other types of
errors.  Sampling error is a measure of sampling variability--that is, variation
that occurs by chance because a sample rather than the entire population is sur-
veyed.  Survey data also are subject to nonsampling errors, such as those which
can be introduced into the data collection and processing operations.  Estimates
not directly derived from sample surveys are subject to additional errors resulting
from the specific estimation processes used.  The sums of individual items may not
always equal the totals shown in the same tables because of rounding.  Unemployment
rates are computed from unrounded data and thus may differ slightly from rates com-
puted using the rounded data displayed in the tables.

   Use of error measures.  In 2005, the LAUS program introduced several improve-
ments to its methodology.  Among these was the development of model-based error
measures for the monthly estimates and the estimates of over-the-month changes.
The introductory section of this release preserves the long-time practice of high-
lighting the direction of the movements in regional and state unemployment rates 
and state nonfarm payroll employment regardless of their statistical significance.
The remainder of the analysis in the release takes statistical significance into
consideration.

   Labor force and unemployment estimates.  Model-based error measures for both sea-
sonally adjusted and not seasonally adjusted data and for over-the-month changes are
available online at http://www.bls.gov/lau/lastderr.htm.  BLS uses a 90-percent con-
fidence level in determining whether changes in LAUS unemployment rates are statisti-
cally significant.  The average magnitude of the current year over-the-month change in 
a state unemployment rate that is required in order to be statistically significant at 
the 90-percent confidence level is between 0.3 and 0.4 percentage point.  More details 
can be found on the Web site.  Measures of nonsampling error are not available, but ad-
ditional information on the subject is provided in Employment and Earnings Online at 
http://www.bls.gov/opub/ee/home.htm.

   Employment estimates.  Measures of sampling error for state CES data at the total
nonfarm and supersector level and for metropolitan area CES data at the total nonfarm
level are available online at http://www.bls.gov/sae/790stderr.htm.  BLS uses a 90-
percent confidence level in determining whether changes in CES employment levels are 
statistically significant.  Information on recent benchmark revisions for states is 
available on the Internet at http://www.bls.gov/sae/.

Additional information

   More complete information on the technical procedures used to develop these esti-
mates and additional data appear in Employment and Earnings Online.

  Estimates of labor force and unemployment from the LAUS program, as well as nonfarm
employment from the CES program, for over 300 metropolitan areas and metropolitan New
England City and Town Areas (NECTAs) are available in the news release, Metropolitan
Area Employment and Unemployment.  Estimates of labor force, employment, and unemploy-
ment for all states, metropolitan areas, labor market areas, counties, cities with a
population of 25,000 or more, and other areas used in the administration of various
federal economic assistance programs are available on the Internet at http://www.bls.
gov/lau/.  Employment data from the CES program are available on the Internet at 
http://www.bls.gov/sae/.

   Information in this release will be made available to sensory impaired individ-
uals upon request.  Voice phone:  (202) 691-5200; TDD message referral phone:
1-800-877-8339.