The report argues that heads' influence is limited

Although the government has placed much emphasis on school leadership, research from a think tank says the impact of changing head teacher is limited.

Successful schools continue to be successful when heads change - and the same is true of unsuccessful schools, says research from Policy Exchange.

Head teachers' leaders rejected the claim as "nonsense".

The research commissioned by the think-tank examined the extent to which school achievement was affected by a change of head teacher - and concluded that in the first five years there was no clear pattern of improvement.

It is a massive challenge to the existing orthodoxy and raises many questions about our emphasis on leadership James O'Shaughnessy Policy Exchange

And it argues that there is little evidence to support the idea of a new head teacher acting as the "hero" rescuing a school from failure.

"We were very surprised to find that head teachers have little impact on the quality of learning and the attitudes of pupils in their schools," said Policy Exchange's head of research James O'Shaughnessy.

Cycle of failure

"It is a massive challenge to the existing orthodoxy and raises many questions about our emphasis on leadership."

The role of head teachers in turning around a struggling school has often been emphasised in government initiatives - but the report argues that the way that head teachers operate tends to reinforce the status quo.

In successful schools with a strong ethos, the report says it is beneficial for head teachers to promote stability and continuity.

But in a failing school, stability and continuity will mean perpetuating weaknesses, so the report calls for a different, more interventionist style of headship - with much greater autonomy over pay and allowing heads to recruit and reward successful staff.

Anyone who has worked in a school will know it is nonsense to say that headteachers do not have an impact on pupil learning Martin Ward Association of School and College Leaders

It also calls for the replacement of senior managers and governors in such struggling schools - and the doubling of core funding.

Researchers Jeff Searle and Peter Tymms at Durham University suggested that the lack of impact on performance from changing head teacher was a reflection of schools as "loosely coupled" institutions - with heads detached from direct contact with pupils.

They suggested that "the ability to influence performance diminishes rapidly the further one is from the pupil".

'Nonsense'

However co-author of the report Daniel Moynihan, principal of Harris City Technology College, put forward a different interpretation.

He points to the difficulty in recruiting the most able head teachers to work in tough schools. "Generally the applicant field for such posts is usually small," he says.

The findings of the report were rejected by the Association of School and College Leaders.

"Anyone who has worked in a school will know it is nonsense to say that headteachers do not have an impact on pupil learning," said the union's deputy general secretary, Martin Ward.

"They do this by setting high standards for teaching quality and ensuring these are achieved.

"In fact, the report says that the most important thing heads can do for their pupils is to make sure that there are good teachers in their classrooms."

Toby Salt of the National College for School Leadership said it was clear head teachers and all school leaders did play a critical role in improving schools.