How the OECD data was retrieved (July 2021)

- Go to https://stats.oecd.org/Index.aspx?DataSetCode=QNA
- Customize table
- Select all OECD countries (38)
- Go subject by subject: GVA (GDP output approach) / employment 
- In each case; select the total as well as all ISIC Rev.4 sectors and subsectors
  > Careful: for employment/hours there is no total service sector, only the subcategories
    Therefore these data have 12 options for the field 'Subject', whereas the GVA data has 13 options (see also the zz_GLOSSARY file)
- Measure:
  > For GVA, choose National currency, chained volumes, national reference year, quarterly levels, seasonally adjusted 
  > For employment, choose: Persons SA/Persons nonSA/Hours SA/Hours Non SA
  > For compensation, choose: National currency, current prices, quarterly levels, seasonally adjusted
- Frequency: start in 1990:Q1
- Download as csv files -> gives the files starting with "00_"
- Then manually add the "Quartnum" variable and save as xls -> gives the files starting with "01_"
  > The Quartnum variable will be used in Stata to properly define the data as quarterly data
- Then continue with Stata do files
