Indeed, there is nothing new about teachers moving in and out of the profession.
What the new Education Secretary wants to change is the belief amog teachers that members who do not stay through to the age of 65 testify to a failure of the profession.
This may seem rash at a time of acute teacher shortages, but she is right to face reality.
There is something ironic about a profession which spends considerable time teaching children about change and their likelihood of having to retrain for four separate careers over their lifetime not applying the principle to their own jobs.
Leader, June 12