PISA 2025: High-income students in Spain fall twice as fast as low-income peers

PISA 2025: the gap is closing from the top, and nobody knows how to close it

The PISA 2025 report, published in September, delivers a headline that breaks the rulebook: in Spain, students in the top socioeconomic quarter have lost 33 points in Reading since 2022, compared with the 15.1 points lost by the most disadvantaged quarter. In Mathematics, 24.2 versus 10.5. In Science, 12.6 versus 4.5. The decline is more than twice as steep among those who have the most. And it is not an exclusively Spanish phenomenon: the OECD detects the same pattern, though on a smaller scale.

It is worth not confusing level with change. High-income students are still scoring higher, and by a wide margin: in Science, the distance between the top and bottom quarters is around 71 points, more than three school years according to the report's own equivalence. What is happening is that this advantage is narrowing, and it is narrowing because the top is plummeting. The OECD calls it "weakening of the performance of traditionally high-performing students." An elegant euphemism for saying that the system no longer produces excellence, not even among those who pay for it.

Why is performance falling faster among students from higher socioeconomic backgrounds?

The most frequently cited explanation points to classroom composition. The thesis: groups used to be more homogeneous by social origin and are now more mixed, so that the student from a well-off family shares a desk with realities they never encountered before. It is a plausible but unverified hypothesis. There are also those who point out that paid education is no longer a refuge: if the collapse reaches private and state-subsidised private schools, the problem is not ownership but the system itself.

In fact, the report dismantles that last prejudice with its own numbers. Without adjusting for the socioeconomic and cultural index, private schools achieve better results in Science. Once adjusted, the gap narrows considerably. Translation: much of the private sector's advantage was simply its students' postal code.

The resilient students the report does highlight

There is one figure the OECD underscores and public conversation has ignored: 13% of Spanish students in the lowest socioeconomic quarter reach the top performance quartile in Science. These are the so-called academically resilient students, and they slightly exceed the OECD average of 12%. In other words, background matters, but it does not determine everything.

At the same time, the report finds that Spain is evolving worse than the average across all segments: while the OECD observes improvements among low- and mid-level students in Science, here the deterioration is generalised and finds only one exception in the third quarter of the ESCS index in Science. A country sinking as a whole.

Sample pitfalls and the debate over the test

Another shadow hangs over the reliability of the test. According to published reports, several Spanish regions allegedly excluded more students than allowed: Murcia is said to have left out 12% and the Balearic Islands 7.5%, when the limit was 5%. Leaving migrant students or those with learning needs out of the exam inflates the exemption rate and glosses over the result. If the figures are bad even with cheating, the real ones are dizzying.

And then there is the fundamental objection: PISA is an anonymous exam that does not count towards grades. Why would anyone make an effort? Those who want real grades stake them on the EBAU (Spain's university entrance exam). Perhaps the report measures less about knowledge than about willingness to fill in bubbles on a Tuesday morning.

With the gap closing from the top, the Spanish system faces an uncomfortable paradox: it levels down at the cost of deflating the best. No one has yet explained how to raise the floor without sinking the ceiling.