Do certified teachers make a difference even after demographic adjustment?
Raw correlation charts between teacher certification and merit value tell only half the truth. Municipalities with a high share of certified teachers are often also municipalities with favourable socioeconomic profiles. The SALSA model makes it possible to go one step further.
Here we plot municipalities' teacher certification against their average SALSA score — that is, how much better or worse the schools perform than what the pupils' backgrounds predict. A positive relationship is not proof of causation, but it is a stronger policy signal than raw merit values.
The pattern in the data is positive but not deterministic. Municipalities with very high certification rarely end up at the very bottom, but there are also municipalities with relatively good certification and weak SALSA score. This suggests that teacher certification is important but not the sole explanatory factor — leadership, working environment and local governance also play a role.
Perhaps most interesting is which municipalities manage to combine high certification with a clearly positive SALSA score. There you will find candidates for closer qualitative study: what are they doing right, and what can others learn from them?
Statistics: academic year 2023/24. Source: Skolverket open data, Kolada and SCB. Processed by Skolkoll. Glossary · About the data.