Improving Occupational ISCO Classification of Multilingual Swiss Job Postings with LLM-Refined Training Data

In the modern labour market, taxonomies such the European Skills, Competences, Qualifications and Occupations (ESCO) classification are used as an interlingua to match job postings with job seeker profiles. Both are classified with respect to ESCO occupations, and match if they align with the same occupation and the same skills assigned to the occupation. However, matching models usually struggle with the classification because of overlapping skills and similar definitions of occupations defined in the ESCO taxonomy. This often leads to imprecise classification outcomes. In this paper, we focus on the challenge of the classification of job postings written in Italian or Spanish against ESCO occupations written in English. We experiment with multilingual embeddings, zero-shot classification, and use of a large language model (LLM) and show that the use of an LLM leads to best results. Furthermore, we also explore an alternative automatic labeling method by prompting three top-performing LLMs to annotate the test dataset. This approach serves both as an experiment on the usability of automatic labeling and as an evaluation of the reliability of the automatically assigned labels, involving human annotators.