Paying teachers on the basis of how well they perform in the classroom is "impossible" to implement and fails to raise standards, experts warned last week.
Dylan Wiliam, emeritus professor of educational assessment at London University's Institute of Education (IoE), told the Specialist Schools and Academies Trust annual conference in Birmingham that performance- related pay "does not work".
Daniel Pink, bestselling author and once speech writer to former US vice-president Al Gore, told the same conference that financial incentives have "little impact on performance".
The warnings came days after education secretary Michael Gove outlined plans to give headteachers more flexibility over paying staff on a performance-related basis in his white paper, The Importance of Teaching.
The paper states: "We want to see schools making more use of pay flexibilities. We also wish to extend these flexibilities, so that schools can attract good graduates into the profession and reward high performance."
According to the document, early next year the Department for Education (DfE) will ask the School Teachers' Review Body to recommend how to make the existing pay and conditions framework "less rigid".
But Professor Wiliam dismissed the idea, saying it "does not work". "If a headteacher sees a jump in results in Year 9, does he give the Year 9 teacher a bonus when the results are most likely the result of the work of Year 7, Year 8 and Year 9 teachers?" he said.
"It (performance-related pay) is impossible to do in principle - it doesn't work. Evidence from the US shows that giving extra dollars to a teacher does not make results go up."
He added: "It is not like a teacher says, 'I have a secret method of teaching fractions, but I'm not going to use it until you pay me more money'."
Professor Wiliam's words echo those of Mr Pink, whose latest book, Drive: The Surprising Truth About What Motivates Us, is in its sixth month on the New York Times bestsellers list. Mr Pink cited a study undertaken by the Federal Reserve Bank, which showed that increasing pay to motivate people to carry out "rudimentary cognitive tasks" actually lowered performance.
"Once you pay people enough, any additional amount of money has little impact on performance. The best use of money is to pay people enough to take money off the table, so that it is no longer an issue," Mr Pink said.
John Bangs, IoE visiting professor, said: "Individual performance- related pay risks poisoning everything around it in terms of collaborative professional development."
The DfE pointed to evidence from this year's Organisation for Economic Co-operation and Development report as proof of the need to give heads the ability to reward high-performing teachers.
In its evidence booklet A Case for Change, published alongside its white paper, the DfE said: "In less effective systems, highly skilled teachers tend to work in the most advantaged schools. In the most equitable systems, incentives, rules and funding encourage a fair distribution of teaching talent."
But the OECD said ...
An international study of 23 countries carried out last year found that schools around the world should introduce performance-related pay to reward good teaching and raise standards.
Three out of four teachers told the Organisation for Economic Co-operation and Development that they lacked incentives to improve their teaching or be more innovative.
A similar number said their schools would not sack teachers with long records of underperformance.
The results were compiled from the Teaching and Learning International Survey, distributed to about 90,000 teachers in what is claimed to be the first ever international study comparing their working conditions.
"The findings suggest that there are substantial opportunities for strengthening - or, in most cases, creating - links between teacher appraisal and feedback and the rewards and recognition teachers receive," it said.