When success is hard to measure, it leaves room for doubt, and that leads to teachers trying to play the system and taking their eye off what they should be doing, which is educating kids. Try to introduce PRP without pupil results as part of the matrix and use a "black box" approach where teachers get bonuses for no fair, clear and discernible reason, and you'll create some very angry staff. A system that lacks transparency will not produce the behaviour you want because teachers aren't clear what is being rewarded or why. Back-biting and complaining are inevitable, as is a work environment that is all about personality and politics. 

But hey, it was the head's choice, so in the end, it is his problem. Except that it isn't his choice if he is the head of an LEA maintained school. The pay and conditions document that the unions have long loved and held up as their bible is no longer their ally. Paragraph 22 now insists that schools should introduce PRP, and the unions are in confusion over it. 

The irony of this PRP débacle is that only free schools and academies can choose not to implement performance-related pay. The unions have been famously anti-free school and anti-academy for years, while Gove has been promoting both free schools and academies with great enthusiasm. But while the heads of other maintained schools have to obey the rules, the heads of academies and free schools do not. 

Some PRP proponents imagine that it will magically ensure teachers are paid more. But unlike businesses, if schools work more efficiently and raise their results, they do not bring in more cash. Bankers know that some years they'll get massive bonuses thanks to their hard work and the bank doing well. But next year they might earn half as much if the bank has a bad year. A school doesn't have that luxury. If a head wants to pay Paul an extra £1,000 this year, he necessarily has to take it away from Peter, or the school buys fewer textbooks. Money is finite. And amounts are small: a bonus in a school might be £500 or £1,000 at most. That's the weird thing about money, especially when dealing with people who genuinely want to change the world. Small amounts of money thrown at them won't motivate them and might even insult them. What it will do, however small it may be, is set teachers against each other and make them feel undervalued. 

If a school only has teachers who are in the top 10 per cent of teachers in the country (because they are clever at hiring talent) and are then forced to implement PRP, it means that teachers in the 90th or 91st percentile nationwide (that school's worst teachers) would be financially penalised for being not very good. PRP forces good schools into a zero-sum game that can only end with their good staff walking out the door.

Of course some exceptional circumstances might merit the use of performance-related pay precisely because it is so divisive. If a new head is trying to turn around a failing school, then PRP might be useful for a short while, because he might want to divide the staff and put pressure on some very bad teachers, whose jobs would otherwise be secure, to leave. It would depend on the school's individual situation. This is why any sensible government policy on PRP would allow it to be a choice for all schools. My guess is that the schools that implement PRP will simply give everyone their bonus, making a mockery of what the system is meant to do.

So how do we reward our good teachers? Mentions at briefing, thank-you letters from the head or line manager, shared celebrations for all the staff when school or department goals have been achieved, pep-talks, one-to-one support and feedback as well as promotion are just a few possibilities. All of these help to build a strong culture of collaboration and cohesion, with all the staff united in working towards the success of the school — not just of themselves.