Technical Note
This release presents statistics from the Green Goods and
Services program (GGS). GGS employment level and rate estimates
are published by state, ownership, and industry. Data for GGS are
collected and compiled by the Bureau of Labor Statistics from a
sample of business and government establishments in selected
industries with workers covered by state and federal unemployment
insurance (UI) legislation provided by State Workforce Agencies
(SWAs).
Collection
In an annual survey of business establishments, data are
collected for employment, fiscal year, and the share of revenue
or employment associated with production of green goods or
services at the establishment level. Data collection methods
include mail, computer-assisted telephone interviewing, web, and
fax.
Coverage
BLS sampled from 325 North American Industrial Classification
System (NAICS) industries identified as potential producers or
providers of green goods and services. The GGS survey covers all
private establishments in these industries, such as factories,
offices, and stores, as well as federal, state, and local
government entities in the 50 states and the District of
Columbia.
Concepts
Green Goods and Services. Green goods and services are defined
as goods and services produced by an establishment that benefit
the environment or conserve natural resources. Green goods and
services fall into one or more of the following five groups: (1)
production of energy from renewable sources; (2) energy
efficiency; (3) pollution reduction and removal, greenhouse gas
reduction, and recycling and reuse; (4) natural resources
conservation; and (5) environmental compliance, education and
training, and public awareness.
Industry classification. The industry classifications in this
release are in accordance with the 2012 version of the North
American Industry Classification System (NAICS). Only the 325
industries identified by BLS as producing green goods and
providing green services are included in the scope of the GGS
survey. To ensure the highest possible quality of data, the
Quarterly Census of Employment and Wages (QCEW) program verifies
with employers and updates, if necessary, the NAICS code,
location, and ownership classification of all establishments on a
3-year cycle. Changes in establishment characteristics resulting
from the verification process are annually introduced into the
GGS sampling frame.
Green Goods and Services jobs. GGS jobs are those associated
with producing green goods or providing green services. Some
businesses produce multiple products and services where one or
more may be included in the BLS definition. For these cases, BLS
determined from prior research that businesses often have
difficulty providing employment associated with the production of
green goods and services, while information on the revenue from
the sale of the green goods or services is more readily available
and less burdensome for the respondent to provide. The percentage
of the establishment's revenue related to sale of green goods and
services is used to estimate GGS jobs, which are defined as
employment related to the production of green goods and services
at the establishment level. Sampled establishments that do not
generate revenue are asked to report the share of their
employment involved with the production of green goods and
services. For example, employment related to research and
development, non-profit organizations, government agencies, and
new businesses may provide green goods and services without
generating income.
Employment. Employment includes persons on the payroll who
worked or received pay for the pay period that includes the
twelfth day of the reference month. Full-time, part-time,
permanent, short-term, seasonal, salaried, and hourly employees
are included, as are employees on paid vacations or other paid
leave. Proprietors or partners of unincorporated businesses,
unpaid family workers, or persons on leave without pay or on
strike for the entire pay period, are not counted as employed.
Employees of temporary help agencies, employee leasing companies,
outside contractors, and consultants are counted by their
employer of record, not by the establishment where they are
working. The monthly employment figure provided by respondents
will be compared to employment data BLS has on file as part of
the QCEW program, which comprise BLS’ business register, in order
to verify that data are being collected for the correct
establishment.
Estimates. Estimates of GGS employment and GGS percent of total
QCEW employment are released with the annual GGS news release.
Sample and estimation methodology
Sample. BLS selects approximately 120,000 GGS establishments
per year from the Quarterly Census of Employment and Wages (QCEW)
program. This program includes all employers subject to state
Unemployment Insurance (UI) laws and federal agencies subject to
Unemployment Compensation for Federal Employees (UCFE). Most of
these establishments are selected from the second quarter QCEW
sample frame, while a small sample of new business establishments
is selected from the fourth quarters. The sample is designed to
estimate GGS employment at both national industry and state
industry sector levels of detail.
The GGS sample is divided into three panels, each containing
approximately 40,000 sample units. Two of the three panel samples
overlap with the previous year's sample to produce estimates of
change in green employment. A new sample is allocated and
selected from the panel that does not overlap.
Estimation. A Horvitz-Thompson estimator is used to estimate
GGS employment, based on an establishment's 12-month average
employment over the reference period, percent of revenue or
employment associated with green goods and services, and sampling
weight. The 12-month average employment is obtained from
corresponding QCEW files and is known for each sampled
establishments.
GGS percentage estimates are relative to the QCEW employment of
all industries contained within a particular estimation cell's
NAICS code, not only the 325 industries included in the GGS
scope. For GGS employment percentages, the estimate of GGS
employment is divided by the 12-month average of QCEW employment
over the reference period.
Reliability. GGS estimates are subject to both sampling and
nonsampling error. Sampling error arises from selecting a sample
of establishments rather than the entire business population. To
measure this error, GGS uses a balanced repeated replication
technique to calculate standard errors. Given the standard error
for an estimate, an approximate 90 percent confidence interval
can be constructed by adding and subtracting 1.645 times the
standard error from the estimate.
The standard error of the estimated total GGS employment is
approximately 34,000. The standard error of over the year change
in total GGS employment is about 36,000.
The standard error of the estimated rate of GGS employment is
approximately 0.03 percent. The standard error of over the year
change in rate of GGS employment is about 0.03 percent.
Nonsampling error arises from various sources, such as
establishments failing to respond or misreporting data, coding
and data processing errors, and population coverage. Since GGS
only samples establishments in 325 industries predetermined to
potentially have GGS employment, any green goods and services
produced or provided in other industries is not captured. GGS is
also subject to errors in the sampling frame, in which some
establishments’ industry codes may be misclassified.
Specialized Procedures. GGS sampling methodology is coordinated
with the Occupational Employment Statistics survey. Sampling
overlap between the two surveys is maximized for additional
inference to be made about green staffing patterns. Such
inferences are not included as part of this GGS release.
Methodological changes
NAICS 2012 Conversion. The original survey estimates for 2010
were based on the 2007 NAICS classification. In that reference
period, data were collected for industries defined in the GGS
scope according to their NAICS classification at that time. The
2011 survey estimates are based on the 2012 NAICS classification,
which impacted the scope of the GGS survey. Some private-
ownership manufacturing industries that were not included in the
2010 GGS scope combined with in-scope industries. Thus, for 2011
estimates, some establishments that were previously out-of-scope
are included in the survey. Revised 2010 estimates are based on
the 2012 NAICS classification.
Imputation. Establishments that are sampled in both survey
years but only report usable data for one year are imputed. Three
methods are used to impute missing green percent values: hot deck
imputation; overlays; and mean imputation.
Benchmarking. Benchmarking procedures were revised to
incorporate ownership for both survey years.
For more information. For more detailed information on these
methodological changes, please visit the Technical Note section
of the GGS web page at www.bls.gov\ggs.
Other information
Information in this release will be made available to sensory
impaired individuals upon request. Voice phone: (202) 691-5200;
Federal Relay Service: (800) 877-8339.
