Alison Wolf has provided many comme

Alison Wolf has provided many comments and helpful suggestions on successive drafts of
this paper. Comments from Anna Vignoles on an earlier draft also led to many improvements. I accept full responsibility for any errors that remain. Andrew Jenkins is a member of the Centre for the Economics of Education and of the Institute of Education, London.
The Centre for the Economics of Education is an independent research centre funded by the
Department of Education and Employment. The view expressed in this work are those of the
authors and do not necessarily reflect the views of the Department of Education and
Employment. All errors and omissions remain the authors.