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.