Pupil attainment rises 'substantially' more in MATs, finds study

Schools that join academy trusts improve pupil attainment “substantially more” than those run by local authorities, analysis suggests.

The Confederation of School Trusts (CST), which carried out the study, said its findings strengthen the case for continuing the move towards a fully trust-led school system, as outlined in the government’s schools White Paper.

However, the precise size of the effect of joining a trust is hard to establish, according to an independent evaluation of the findings.

Joining a trust ‘improves students’ results’

The CST research examined Department for Education performance data covering 12,400 schools between 2007 and 2025.

For each year during that period, schools were ranked on how they performed on headline performance measures.

The study then tracked whether schools moved up or down the ranking over time.

Over the 18-year period, academies rose up the rankings by five places on average, while local authority-maintained schools fell by 0.27 places.

CST concluded that if all the schools had been in trusts, 16,000 more students would have achieved a grade 4 or above in English and maths GCSE in each year, and 5,400 more primary-age children would have reached the expected standard in reading, writing and maths.

Professor Daniel Muijs, of Queens University Belfast, who independently reviewed the study, said the findings were “clear and robust”, but the exact size of the effect was harder to establish. There is “residual uncertainty” over causality, he added.

Smaller effect for converter academies

The apparent benefit of joining a trust varied significantly by school type, according to the research.

Among converter academies - former LA-maintained schools that have chosen to academise - the estimated effect was far smaller than for sponsor-led academies that were forced to academise after underperforming.

Commenting on CST’s findings, Jon Andrews, head of analysis at the Education Policy Institute, said previous studies had found “either relatively limited or no effects of academisation on attainment”.

The CST analysis shows there is still “considerable variation” between school groups and even within them, Mr Andrews said.

“We need to explore what it is that the highest-performing groups do that makes the difference,” he added. “As we move towards a system where all schools are in a group of some kind, that is going to be the critical question.”

Questions over causation

The CST said its analysis tried to distinguish between the effects of joining a trust and wider changes affecting schools nationally.

Its report acknowledges that schools that later joined trusts were already moving differently in the rankings before they converted.

This makes it harder to understand how much of their later improvement was caused by joining a trust, rather than being part of a trend that had already started.

Paul Whiteman, general secretary of the NAHT school leaders’ union, said: “Fantastic schools come in all shapes and sizes, and they may be in multi-academy trusts, standalone academies or maintained schools.”

Some leaders reported benefits from being part of a MAT, but others remained unconvinced academisation was right for their schools, he added.