The stability index (Swedish: stabilitetsindex) is a composite measure used to estimate how stable the staff is at a school or in a municipality. Since there is no open data on staff turnover per school unit, changes in teacher qualification rates and student/teacher ratio over time are used as proxy measures.
How is it calculated?
The stability index is primarily based on the trend in qualification rate (the proportion of qualified teachers) over recent years. A school or municipality that maintains or improves its qualification rate is considered more stable than one experiencing declining qualifications — since declining qualifications often mean that experienced teachers are leaving and being replaced by unqualified staff or substitutes.
Interpretation
- Stable (↑ or →): The qualification rate is unchanged or increasing over at least 3 years.
- Unstable (↓): The qualification rate is declining, which may indicate increased staff turnover or difficulties recruiting qualified staff.
Limitations
The stability index is an approximate measure and not a direct measurement of staff turnover. A school can have high staff turnover but still maintain its qualification rate if the new hires are qualified. The index provides an indication but should be interpreted alongside other factors such as student/teacher ratio and student results.
Data source
The calculations are based on Skolverket's statistics per school unit and Kolada's municipality-aggregated data on qualification rates. See also staff turnover for more information on the background to this measure.