It appears that schools are having trouble recruiting head teachers. Many are having to readvertise for posts that have been filled. It is suggested that few are willing to face the additional risks that come with being a head teacher in return for a relatively narrow differential in salary between a head and other senior teachers.
The lack of a sufficient differential in salaries may well be a result of the centralisation of teachers' pay bargaining. When pay is set by a combination of union pressure, the advice of School Teachers' Review Body and the decisions of ministers it won't reflect an interplay of supply and demand. Without market wages you almost invariably get over or under supplies of certain staff. There is an excess of applicants to become firemen and not enough head teachers.
On the other side of the equation, the way that John Bangs, from the National Union of Teachers, describes the risks is revealing:
"Your future does depend on getting a good Ofsted report, and hitting national curriculum test targets.
"It feels like Russian roulette."
It is possible for people to thrive on risk. When people enjoy career risk the term used to describe it is normally something like "challenge" and motivated employees look for it in a career. The problem is when that risk feels arbitrary, like Russian roulette. Ofsted reports are too often more a test of a head teacher's stage management than the inherent quality of the school, as they are pre-announced. National curriculum test targets are clearly affected by the quality of school but heavily biased by increasing "teaching to the test" and falls in standards in some subjects, which leave test results ever more distantly connected to actual education.
The shortage of head teachers shouldn't be separated from the broader problems of an education system too reliant on centralised political management and monopoly provision.