EWCTS 2021 – Coding

The EWCTS carried out in 2021 collected detailed information from respondents on occupation, economic activity, education level and geo-classification.

Coding methods

Information regarding the respondent’s occupation was recorded through two open-ended questions which were then coded into the ISCO classification of occupations, version 08, at 4-digit level. A similar procedure was applied to collect information on the sector which was coded at 3-digit level using the classification of sectors of activity, NACE 08 Rev 2. In order to protect the identity of the respondent, the microdata made available to the general public provide information at ISCO 2-digit and NACE 1-digit level.

The question that collected the respondent’s level of education also required some coding work, which was fully integrated into the data collection script. The education categories in the questionnaire were country-specific (that is, based on the local education system), so the responses were recoded in order to obtain the internationally comparable International Standard Classification of Education (ISCED) categories.

The location of respondents, in terms of the regional (NUTS) classification level and degree of urbanisation, was also collected through a separate geo-classification module. This information was then automatically coded to the corresponding NUTS levels.

Quality of the coding

Quality control measures were implemented during the entire process to ensure high-quality coding. Extensive training was provided to interviewers and coders to help them collect the most accurate information that would allow coding at the desired level. In particular, a note was provided to interviewers to guide them on how to capture high-quality information on occupation and industry, two key variables of the EWCTS.

For more detailed information on each of the classifications and the associated coding processes, please see the Coding report (forthcoming).