It's a tangent, yes. My point here (which I didn't articulate earlier) is that one of the arguments against independent schools having to pay business rates is

It's a tangent, yes. My point here (which I didn't articulate earlier) is that one of the arguments against independent schools having to pay business rates is they're indirectly helping the local community through this trickle down effect - sure they're taking in huge sums from overseas students, the argument goes, but that means home students get cheaper education than otherwise. As you say, there's very little evidence for this in practice.