Filip Van Droogenbroeck and Bram Spruyt are astonished that many essential aspects of education are simply not monitored. For example, how much teaching pupils actually receive.
Last week marked the start of the new school year. Tomorrow, the latest PISA results will be published. The 2026-2027 academic year is therefore off to a flying start. Over the past twenty years, the proportion of top-performing Flemish pupils in mathematics has declined sharply. In 2003, around one-third of fifteen-year-olds still belonged to the highest PISA levels. By 2022, that figure had fallen to just 15 per cent.
That is worrying. What strikes us, however, is how strangely the debate is conducted. Crucial elements are overlooked. It begins with the observation that the decline in mathematics performance is not exclusively a Flemish phenomenon. Results have also deteriorated substantially in most other European education systems. That is no excuse, but it does show that the explanation cannot be a purely Flemish matter.
So why are Flanders and those other countries falling behind? PISA does not provide an answer. It signals change, but no OECD report offers a conclusive causal explanation for a decline spanning twenty years. It is difficult to determine from successive snapshots which changes actually caused that deterioration. Rather like Roman emperors giving a thumbs up or thumbs down without ever offering any explanation.
This invariably leads to PISA panic and warnings about the decline of our education system. Experts are summoned, and within days a whole series of explanations is presented. In Flanders, we repeatedly hear about “fun pedagogy”, a culture of merely scraping passes, standards that are too low, insufficient knowledge transfer, or growing social inequalities. One might think all of this has been extensively researched, but that is not the case.
Some of the underlying mechanisms are undoubtedly plausible. We know that good instruction, high expectations and an orderly classroom environment are important for learning. We also know that socio-economic inequality makes the task of schools and teachers more complex because of greater differences in prior knowledge and available resources.
Shortage Occupation
That does not demonstrate, however, that a supposedly declining standard, for example, caused the drop in Flemish PISA results. To establish that, we would first need to show that such practices have systematically changed over time and then demonstrate that those changes are linked to the decline. Apart from anecdotes, this has never been done. Twenty years of PISA panic have also been twenty years of failed educational research.
Against that backdrop, it is striking that one possible explanation receives much less attention: the teacher shortage. Yet this is by no means a recent problem. As early as the first Flemish TALIS survey in 2008, around one-third of teachers worked in schools where headteachers reported that a shortage of qualified staff was hampering education. Flemish labour market reports were already signalling shortages around the turn of the century.
Mathematics stands out in particular. In 2002, 2005 and 2007 it was explicitly listed as a shortage subject. The 2010 SOHO mathematics report even described the classroom situation as “dire”, while a Flemish STEM report concluded in 2015 that the shortage of mathematics teachers had already been a chronic problem for more than twenty years.
It is remarkable that such an obvious issue, present throughout almost the entire period of declining PISA results and regarded by school leaders themselves as a major obstacle to quality education, often plays only a minor role in the search for explanations. How is it possible that, in response to a parliamentary question, the minister had to admit that the number of hours pupils missed lessons because of teacher shortages is simply not recorded? In Flanders, we are becoming champions at designing tests, yet we do not keep track of the most basic educational question of all: did the pupil actually receive teaching?
Unexpected?
This is all the more remarkable because the teacher shortage can hardly be presented as an unexpected crisis. Flemish labour market reports were already warning about shortages around the turn of the century, and the retirement of the baby-boom generation had long been foreseeable. The increase in pupil numbers over the past twenty years was equally predictable. If there is one thing policymakers can plan for, it is long-term demographic change. We quite literally saw this problem coming for decades.
If, after twenty years, anything should still provoke a PISA shock, it may not be that our pupils are achieving lower results. Rather, it should be that a teacher shortage that has been predicted for just as long remains unresolved, and that we have not even made the effort to investigate its effects.
Pupils, teachers and school leaders deserve better.