Hawai i's Green Workforce A Baseline Assessment December 2010

Statistical Sampling
The data presented here is based on a survey
conducted from May to July 2010 of a stratified
random sample of 9,146 worksites drawn from the
Quarterly Census of Employment and Wages (QCEW)
database. The QCEW contains data on approximately
37,674 private Hawai‘i worksites that report to the
State’s Unemployment Insurance Division.
To ensure a representative sample, the State
Department of Labor and Industrial Relations (DLIR)
mailed the survey to a stratified random sample of
the QCEW, including all four counties – Honolulu
(O‘ahu), Hawai’i, Maui, and Kaua‘i. O‘ahu accounts
for about two-thirds of all QCEW worksites, so the
first level of stratification was by county (Figure 2).
Within each county, a cross-section of employers was
randomly selected such that small (1-9 employees),
medium (10-49 employees) and large worksites (50
or more employees) would be represented. In order
to obtain complete data on worksites with potentially
very large numbers of green employees, all large
worksites were sampled. This decreased the variance
in our random sample of small and medium-sized
worksites, thus increasing the power of the sample.
The sample was further stratified to reflect a crosssection
of industries, including traditional industries
and those thought likely to have a large representation
of green jobs. All 19 private sectors in the North
American Industry Classification System (NAICS, see
inset) were randomly sampled. Public Administration
(NAICS 92) was not sampled, but we plan to include
the public sector in the future.
Survey Response and Estimation
Businesses could respond to the survey via internet,
mail, fax, or telephone within a ten-day period of the
deadline. (Businesses that mailed responses prior
to a ten-day grace period following the deadline are
referred to as Wave 1). Based on this criterion, 2,285
surveys were received, yielding an initial response
rate of 25 percent. An aggressive follow-up strategy
12 Hawaiÿi’s Green Workforce: A Baseline Assessment
What is the NAICS?
The North American Industry Classification System
(NAICS) is a system for classifying establishments
by type of economic activity for statistical purposes.
Its purposes are: (1) to facilitate the collection,
tabulation, presentation, and analysis of data relating
to establishments, and (2) to promote uniformity and
comparability in the presentation and analysis of
statistical data describing the economy.
NAICS is used by federal statistical agencies that
collect or publish data by industry. It is also widely
used by State agencies, trade associations, private
businesses, and other organizations. At the heart of
NAICS is a production-based concept of classification;
that is, NAICS classifies each establishment into a
detailed industry based in the production processes
it uses. The NAICS system provides five levels of
classification on detailed codes that have a maximum
of six digits. The classification levels are Sector,
Subsector, Industry Group, NAICS Industry, and U.S.
Industry.
This report focuses on data analysis at the Sector
(2-digit NAICS) level. Including Government (which
is not included herein), there are 20 Sectors in NAICS.
Source: U.S. Office of Management and Budget, Executive
Office of the President.
was pursued with non-responders, which yielded an
additional 1,723 responses (Wave 2). This brought
the total survey response to 4,008 of the original 9,146
sampled worksites, or a final response rate of 43.8
percent.
Upon examination of the data, non-response bias was
detected between Wave 1 and Wave 2 responders.
To address this bias, a logistic regression was used
to estimate propensity scores for prediction of likely
responders and non-responders within the unsampled
data. In the final estimation procedure, Wave 1
sample weights were increased to estimate the number
of green jobs for likely responders, and likewise,
the weight of Wave 2 sample data was increased to
estimate the number of green jobs for likely nonresponders.
This method yields an unbiased estimate
of total green jobs.