WHEN Ewa began looking for jobs, she did not plan to leave the country. She now works as a modern-language teacher at a private school in Dubai, earning three times what she did in London. Perks include free flights home, accommodation, private health insurance and even a furniture allowance. Five years after qualifying as a teacher she is head of her year. Would she return? Her “heart beats for London” but living there “on a teacher salary can be really difficult”, so not soon.

Schools are struggling to recruit enough teachers to deal with a demographic bulge. Yet they are also doing a bad job at keeping those they manage to attract. Among teachers who qualified in 2011, 83% were still in the state sector two years later. Among those who qualified in 2015, just 78% were (see chart). Failing to retain teachers is a problem in itself, but it also points to other issues bedevilling English education.

The most obvious is pay. In September classroom teachers will receive their first above-inflation pay rise since 2010. Meanwhile private-sector wages have grown, so the pay cut taken, in effect, by some teachers (such as those with degrees in physics and economics) has grown too.

But money is hardly the only reason why teachers are leaving. According to research by the National Foundation for Educational Research, teachers on average take a 10% pay cut when they quit and 51% stay in education in some form. That leads many to think that a big part of the problem is the job itself. A small number of schools shoulder an outsized share of the blame. Sam Sims and Rebecca Allen, economists at the UCL Institute of Education, have identified 122 schools that burn through young teachers, each losing more than three times the average number of newly qualified teachers in 2010-14. In their book, “The Teacher Gap”, they write that the schools “are essentially sausage machines, efficiently grinding the fresh meat from teacher training programmes into a grisly paste.” But in most schools the job of teaching takes up more time than it did. Ed Richardson of Keystone Tutors, a London-based firm, reports that the offer of a more manageable workload is a key factor in persuading teachers to become tutors. According to the OECD, a club of mostly rich countries, only teachers in Singapore and Japan work longer hours than those in Britain. British teachers also spend an unusually large proportion of their time dealing with bureaucracy. Mr Sims suspects that changes to the inspection system are the main explanation for a rise in paperwork. A reduction in the number of inspectors used for school visits means that the burden for collecting information increasingly falls on schools. And since 2010 the penalties for a bad inspection have become more severe.

All teachers suffer from more form-filling. But for new ones, who need time to get to grips with the rest of their job, it is an even bigger problem. Unlike other professions, teachers are expected to meet the same standards no matter how long they have been working, notes Matthew Hood of the Institute for Teaching, a graduate school. They are not helped by the fact that teacher training often focuses on theory, rather than on the basics of the job.

None of this would matter if it were only the weakest leaving the profession. But there is no evidence that this is true, says James Zuccollo of the Education Policy Institute, a think-tank. The result is that more inexperienced teachers enter the classroom and children have to form new relationships. When teachers leave because they are miserable, pupils suffer the consequences.