Validating occupational coding indexes for use in multi-country surveys

Occupational coding in multi-country surveys is mostly a black box: have national survey agencies classified the same occupational titles into the same category across countries? This paper attempts to validate the coding from 5-digit occupational titles into the 4-digit occupational units of the international ISCO-08 classification, based on a comparison of coding indexes from national statistical offices. Two research objectives are central. To what extent are occupational titles in the coding indexes similar, when comparing their English translations? What percentage of similar occupational titles is coded similarly across countries? To answer these questions, we merged titles from 20 coding indexes (18 non- English), resulting in 70,489 records. We translated the titles in English, using online dictionaries and Google translate (4.2% could not be translated). We checked for existent codes of the titles, using ILO’s ISCO-08 coding index (10.3% non-existent). The remaining database had 60,559 records, of which 32% had at least one duplicate title (19,044 records). These duplicate records could be aggregated into 5,350 occupational titles. Only 64% of these titles had the same ISCO-08 4-digit code, 70% at 3-digit, 74% at 2 digit, and 80% at 1-digit. Users of multi-country surveys should be cautious when using the 4-digit ISCO-08 codes.