Good schools are good, for the children and for the parents’ blood pressure. But what gets us good schools? An effective headteacher helps. Hopefully, you knew that, but new research from the Education Policy Institute adds to our knowledge, spelling out exactly how much difference a top head makes. Following the careers of more than 22,000 primary and 5,000 secondary heads, the researchers were able to identify when headteachers changed schools and the impact on exam results, which it found was quite a bit. If a secondary school replaces a not very good headteacher with an average one, pupils get a boost equivalent to an extra grade in one GCSE. Replace them with a top head? Make that an extra grade in two GCSEs. The financially minded should note an extra grade bags about £8,000 in higher earnings over your lifetime. Having a good head gets childrens’ grades up, but surprisingly it makes almost no difference to a school’s Ofsted rating. If employing a good headteacher isn’t associated with a higher Ofsted grade, what is? Employing an Ofsted inspector. So finds a second new paper that examines schools where a member of staff also does Ofsted inspections on the side. Such schools are three times less likely to receive a bad Ofsted (an “inadequate” or “requires improvement” score). The paper can’t prove why this happens, but having staff with inside knowledge of what hoops inspectors want to see schools jump through can’t hurt. This raises fairness concerns when 15% of grammar schools are in this position but only 6% of other secondaries. Maybe schools that are focused on their Ofsted grade should prioritise hiring an inspector, not a superhead. Or maybe they should just focus on being a good school. Torsten Bell is chief executive of the Resolution Foundation. Read more at resolutionfoundation.org