Schools with the most effective headteachers see pupil progress boosted by an extra grade in two GCSE subjects, a landmark new study has found.
Research by the Education Policy Institute also found that more experienced leaders and those who stayed in the same school for several years saw a larger boost in pupil outcomes.
The study used national data on all pupils and heads in England between 2004 and 2019 to follow 22,300 primary and 5,400 secondary headteachers and track their impact on metrics like pupil progress, teacher turnover and teacher absences.
The EPI said it ranked headteachers as effective based on whether they improved their schools’ test and exam results.
It then checked how schools with leaders at different points in that ranking fared in terms of metrics like pupil progress, teacher retention and absenteeism.
An “effective” headteacher is one in the 84th percentile of effectiveness in terms of their impact on school results. An average is at the median and a ‘less effective’ head is at the 16th percentile.
The findings prompted calls on government to encourage more high-quality heads to work outside London, for governors and Ofsted to recognise the “cost of losing experienced leaders” and for trusts and councils to encourage their best leaders to work in the most challenging schools.
Here is your trusty Schools Week round-up of the key findings:
1. Most effective heads add two GCSE grades
The study found that a secondary school that replaced a less-effective head with an average leader could expect pupil progress to improve by a month on average, or an extra grade in one GCSE subject.
For primary schools, the impact is the equivalent of about two months of extra progress.
And a secondary school that replaces a less-effective head with an effective head can expect average improvement equivalent to an extra grade in two GCSE subjects.
Previous research found an extra grade in a GCSE is worth about £8,000 in additional lifetime earnings.
Across an average secondary school of 1,000 pupils, “that means switching from an average headteacher to an effective headteacher and retaining them in post for five years could add £8 million to the value of pupils’ lifetime earnings”.
According to the report, the importance of headteachers for pupils “has never been quantified in England”, making it “hard for policymakers and school governors to make informed decisions about budget allocation between leadership and other school resources”.
Multi-academy trusts and local authorities should “consider how they can encourage their most-effective school leaders into the most-challenging schools”.
2. Experience and tenure boost progress
The effects on pupil progress found in the study “seem to be stronger for headteachers that remain in the school for several years”.
For example, the effect of switching from an average to an effective head jumps from one month’s additional progress to two.
Heads’ effectiveness also does not depend on the “match” between them and their school, suggesting “good headteachers are equally effective in all schools we observe them in”.
The study also found experienced heads tended to be better heads.
In both phases, having five more years of experience is associated with an extra two months of progress, or an increase of 1.25 GCSE grades for secondary school students.
“In value, this translates into £10,000 additional lifetime earnings for each secondary school pupil and an additional £10m of net present value for each average school.”
The report said school governors and Ofsted inspectors should “acknowledge that it may take years to realise the full improvement in results from switching headteachers and support new headteachers accordingly”.
They should “also recognise that the cost of losing experienced leaders is high and focus on supporting them to remain in the profession”. Schools Week revealed last year how headteacher turnover leapt by more than a third since before the pandemic.
3. Best heads also reduce teacher turnover
Those who are most effective at improving attainment also seem to reduce “both annual teacher turnover and four-year cumulative teacher turnover”.
However, while effective heads were found to reduce teacher absenteeism in secondary schools, “no consistent effect was discovered in primary schools”.
At secondary, switching from a less-effective headteacher to an average headteacher brought a reduction in absences equal to an average of 10.7 days.
But the report warned: “All effects are small, which suggests that these are not the most important mechanisms through which headteachers influence pupils’ progress.”
4. London has more effective leaders
Researchers found headteacher effectiveness varied “little” by school characteristics – effective heads were equally distributed across academies and LA schools, and between more and less affluent schools.
However, they also found that headteacher effectiveness was greatest in London, where primary heads improved progress by a month more than the nationally-average head.
The north east “also appears to have slightly more effective primary headteachers, though that effect is not replicated in secondary schools”.
Secondary school heads in London contributed about two thirds of a GCSE grade, or one month of additional progress.
To close the attainment gap, government should encourage “more high-quality headteachers to work in the most-disadvantaged schools and in areas outside London”.
5. Best heads don’t earn much more
More effective heads earned more money, but not much more. Highly-effective leaders averaged £61,700 at primary and £91,800 at secondary, compared to £59,300 and £86,400 respectively for less-effective heads.
While the results “may signal that some governors can identify good headteachers, this is a relatively small pay premium when compared with the large benefit that a more-effective headteacher brings to a school”.
Effective secondary heads also earn better Ofsted grades, “but these differences are extremely small”. Primary schools with more-effective headteachers do not earn better Ofsted grades.