Measures the degree of specialization of each skill within each profession.
A Balassa index >= 1 indicates the skill is more concentrated in that profession
than across all professions (i.e., it is "specific" to the profession).
Usage
compute_balassa_index(skills)
Arguments
- skills
A data.table with one row per skill occurrence in an announcement.
Required columns: preferredLabel (profession), escoskill_level_3 (skill).
Value
A data.table with columns: preferredLabel, escoskill_level_3, N,
tutte_professioni, tutte_le_skills_della_professione, tutte_le_ricorrenze,
balassa_index, and specializzazione ("specifica" if >= 1, "non specifica"
otherwise).
Details
The formula for each profession-skill pair is:
$$B = (N_{skill,prof} / N_{prof}) / (N_{skill,all} / N_{all})$$