It is no easy job to find every reason for the increase in the number of teenagers who run away from their homes, but, on the whole, two factors shout louder than others.

E. T. S. says it takes additional precautions, such as collecting handwriting samples to reduce the chance that students will hire someone to slip in, in their stead, after breaks.

They favour using more sophisticated "assessments" in place of tests, want to value a broader range of skills, punish schools less and support them more.