based on U.S. estimates, which are obtained from the 2018 Occupational Employment and Wage Statistics (OEWS) published by the U.S. Bureau of Labor Statistics.<sup>9</sup> The O*NET-SOC 2010 codes are linked to their corresponding four-digit ISCO-08 codes using the U.S. Bureau of Labor Statistics correspondence table between SOC 2010 Codes and ISCO-08 categories. This correspondence, as well as the employment estimates in the OEWS, is available at the six-digit level of the SOC. At the same time, the O*NET-SOC 2010 classification of green occupations is presented with an eightdigit level of detail. Since 12.7 percent of the 6-digit SOC occupations are associated with more than one 8-digit SOC, the total number of workers in a 6-digit SOC occupation was equally distributed among the 8-digit SOC codes associated with it.<sup>10</sup> As an example, Table 2 shows how the share of green occupations was constructed for a specific ISCO code, representing the probability that an individual with an occupation in this ISCO code has a green job.

**Table 2 – Example of the methodology used to estimate the probability for an ISCO-08 code to represent a green occupation.**

|ISCO-08<br>Code|O*NET-SOC 2010<br>Code|Green<br>Job?|2010 SOC<br>Code|Number of US<br>workers|“Simulated”<br>Number of US<br>workers|Share of Green<br>occupations|
|---|---|---|---|---|---|---|
|1234|17-2061.01|Yes|17-2061|10|5||
|1234|17-2061.02|No|17-2061||5|5%<br>|
|1234|17-2063.00|No|17-2063|40|40|=5/(5+5+40+50)|
|1234|17-2064.00|No|17-2064|50|50||

Source: Own elaboration based on O*NET database (Green Occupations & O-NET-SOC 2010 Occupation List), U.S. Bureau of Labor Statistics correspondence between SOC 2010 Codes and ISCO-08 categories, and 2018 Occupational Employment and Wage Statistics.

> 9 Estimates for 2018 are used since it is the most recent year in which survey data was collected using the 2010 SOC classification. After this year, estimates use a hybrid of the 2010 and 2018 SOC systems, which makes the link with the O*NET-SOC 2010 classification of green jobs less direct. While employment estimates from this program are not perfect since they exclude selfemployment, they are the only source of publicly available data with information at the 6-digit level of the SOC.

> 10 This assumption had to be used in other cases in which more information was not available: 1) for six SOC occupations at sixdigits for which U.S. employment data was only available at five digits (in these cases employment at 5-digits was equally distributed among the SOC occupations at six-digits corresponding to the 5-digit code); 2) to estimate employment in some of the six cases in which the SOC classification from O*NET and OEWS were different: SOC 211018 in OEWS (Substance Abuse, Behavioral Disorder, and Mental Health Counselors) was equally distributed between SOC 211011 (Substance Abuse and Behavioral Disorder Counselors) and 211014 (Mental Health Counselors) from O*NET; SOC 512028 in OEWS (Electrical, Electronic, and Electromechanical Assemblers, Except Coil Winders, Tapers, and Finishers) was equally distributed between SOC 512022 and 512023 from O*NET (Electrical and Electronic Equipment Assemblers + Electromechanical Equipment Assemblers); SOC 512098 in OEWS (Assemblers and Fabricators, All Other, Including Team Assemblers) was equally distributed between SOC 512092 and 512099 from O*NET (Team Assemblers + Assemblers and Fabricators, All Other).

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