This week’s Labour Party conference has put forward a proposal to radically restrict private schools. In essence, the policy seems to have three strands - remove the beneficial tax arrangements, restrict the entry to universities from private schools to 7% of the entry and, at the most extreme, to get rid of the private schools entirely, taking over their assets. The first of these seems eminently doable. Most commentary seems to suggest the last is just rhetoric and is unlikely to happen. But what interests me with a statistical hat on is that 7%. Because it makes no sense at all. While it is true that only 7% of children attend private schools, this isn’t a sensible number to apply here. If you want a flat attendee number, then what’s important is the number of students taking A-levels, where the percentage is more like 15%. But even this figure is misleading. The problem is that far more private schools are selective than are state schools. It would be ridiculous to exp...