Does repeating a year work? What the evidence says, and what it costs Spain

Repeating a year is one of the oldest tools in Spanish schools, and one of the most studied anywhere. The question parents and teachers type into a search box, whether it helps a child who is struggling, has a fairly clear answer by now. On average it does not, it costs a great deal, and the cases where it seems to work turn out to be cases where something else was doing the work.

What the research finds

The most-used summary of the evidence is the Teaching and Learning Toolkit of England's Education Endowment Foundation (EEF), which pools studies on dozens of school interventions. For repeating a year it found 71 studies that met its criteria. The average pupil who repeats makes about three months less progress over the following year than a similar pupil who moves up, and about four months less in secondary school. The toolkit rates the security of that evidence as low, since nobody randomly assigns children to repeat, and it summarises the intervention as a negative impact for a very high cost. Two more findings matter for Spain: disadvantaged pupils are more likely to be held back, and the negative effects are greater for them.

The OECD reached the same verdict from PISA. Its 2014 note Are disadvantaged students more likely to repeat grades? concluded that grade repetition has shown no clear benefit for the students held back or for school systems as a whole, and called it a costly way of handling underachievement. That note picked out Spain. In PISA 2012, 32.9% of Spanish 15-year-olds had repeated, against an OECD average of 12.4%; Spain and Belgium were the only countries where repetition had risen since 2003; and in Spain more than one in two disadvantaged pupils had repeated.

The best Spanish review is a 2024 EsadeEcPol report on two decades of research, since published by the education ministry. It sums up the international studies with a useful distinction: repetition on its own, with a negative effect on learning, and repetition with tutoring and extra support, which can have a positive one. It cites the work of Brian Jacob and Lars Lefgren in Chicago, where summer school combined with repetition helped younger pupils in third grade and did almost nothing for sixth graders, and where repeating eighth grade made pupils more likely to drop out. In systems with a uniform common school, the report adds, such as France or Spain, the effect is null or negative. The support was the active ingredient all along.

How common it is in Spain

Spain has cut repetition sharply and still does far more than its neighbours. A 2025 European report from Maastricht University Press, mapping rules and practice across the continent, finds that the cumulative rate at 15 fell from 33% in 2012 to 22% in 2022, and that France followed a similar path, from 28% to 11%. In lower secondary, Spain reported the highest retention rate in Europe in 2022, at 15%. In countries where the law treats retention as exceptional, the report notes, rates sit between 1% and 14%.

EsadeEcPol's figures for PISA 2022 put Spain at almost 22%, against 9.1% across the OECD and 9.5% in the EU, and warn that the emergency promotion rules of 2019–20 after the lockdown lowered that number. The PISA comparison with Estonia we published last week adds that at the same maths score a disadvantaged Spanish pupil is almost four times as likely to have repeated as an advantaged one.

What the law says

The rules are already strict on paper. Royal Decree 157/2022 for primary school says the teaching team decides promotion jointly at the end of each cycle, that a pupil can repeat only once in the stage, that the decision is always exceptional, and that a pupil who repeats gets a specific support plan. The decree also asks schools to use support and reinforcement to avoid repetition, particularly in disadvantaged settings. Royal Decree 217/2022 for ESO repeats the principle: repetition is exceptional, comes after ordinary support has been exhausted, and is allowed once in ESO and twice at most across compulsory schooling, with one extra year in the fourth year of ESO as an exception.

What it costs, and a better use of the money

EsadeEcPol puts public spending on repetition in primary and ESO in 2021–22 at between €1,448 and €1,704 million, 89% of it in public schools and around three-quarters in ESO. Per pupil it ranges from €46 in state-funded private primary schools to almost €700 per pupil in public ESO. The longer bill is larger: through its link to early school leaving, the report estimates the 2012–13 cohort's repetition will cost an extra €6,796 million of public money over time.

The left is right that repetition falls hardest on poorer pupils and widens the inequality school is supposed to narrow. The market-liberal tradition is right that a certificate has to mean something, and that a pupil who moves up without having learned the material is let down by a system that pretends otherwise. Both sides tend to argue about the decision at the end of June. The evidence points to what happens around it.

So the position that fits neither camp is promotion under a catch-up contract. The pupil who falls short moves up with their class and signs, with their family, a plan: small-group tutoring during the next year, a summer course where the gap is large, and a clear test at the end of it. Repetition stays for the rare case where that support has already been tried and failed, which is what the decrees already say. The €1.5 billion that repetition costs each year is the obvious budget for it. And because the decree gives the decision to each teaching team, regions can test it as Karl Popper would want, in pieces, comparing schools that adopt the contract with schools that do not before making it the rule.