"In my current school the teachers seem happy and have no plans to quit. Many have taught there for 20 or 30 years and educated the parents of the current students. Indeed, teacher turnover is so low that I very nearly didn't get a job. When I started looking last spring, there were 120 vacancies for business studies and economics teachers in London; in the whole of the North East there were only three. In the highest-achieving London academies a quarter of the staff quit every year — not just because they can't afford flats but because they are wrung out by the scale of the work. This is the trade-off: this sort of system gets the best possible GCSE results, but the teachers, and sometimes the students, get burnt out achieving it."