The Institute for Public Policy Research (ippr) says it should be harder to become a qualified teacher, and that there should be more serious sanctions for underperforming staff. Research produced by the Centre for Market and Public Organisation for the think-tank shows having a teacher rated 'excellent' rather than one rated as 'bad' is worth a GCSE grade. Having a teacher rated 'good' rather than 'bad' was worth 0.6 of a grade. Report co-author and ippr associate director Julia Margo said:...