Because DESC refuses to disclose the funding formula, all stakeholders cannot have an honest, transparent discussion about it. From my back of envelope, attempt to reverse out the numbers on a like for like basis (take into account FSM, EAL, SEN) as you state it roughly 10% lower than UK average. Bulk budgets (rightly so) on teachers who are on fringe London weighting, which is higher than UK average. Fact IoM does not have a pupil or subject premium, further distorts the system versus the UK. But clear the lower funding versus UK falls squarely onto the shoulders of children.