My first move would be to withdraw charitable status from such schools.
Happily, the Scottish government may well have the powers to do this once the Scotland Bill is made law.
And that would achieve what exactly? - you don't improve education by destroying excellence.
Might it not be better to concentrate on getting state schools up to and even beyond the levels of private schools?
Firstly not all private schools are excellent and many aren't as good a state schools when the characteristics of their intake are taken into account, e.g. by looking at added value, in other words the progress the students male during the time at the school. The notion that all private schools are beacons of excellence is absolutely laughable.
Secondly removing tax breaks (which is what charitable status is) increases the revenue of the treasury which can then be used to increase funding for state schools.
Well, if they the schools are crap - Why would anyone pay good money to get a worse education?
If you are correct, I don't understand why they exist.
Oh the naivety.
There are plenty of people with more money than sense in all sorts of areas and that includes education. Interestingly where I live there are some of the best state schools in the country (and some less good ones) and also a range of private school, ranging from excellent to ... well ... schools that have taken on really poor teachers from the state sector who really weren't good enough in state school, but have now been put in positions of senior responsibility in private schools - wtf!!
Anyhow, with my wife I own a preschool nursery which caters for children up to 5 so before the age when there is universal state provision. SO not surprisingly we have kids who head off to both state schools and private schools. And you would be astonished by the levels of snobbery that exist in some people in justifying sending their kids to private school, indeed often to private schools that are worse than state schools they could have chosen. Common examples are:
1. If you pay for it directly (i.e. private) it must be better than a state school - the kind of 'throw money at it' argument.
2. The socially mobile social climber snob - we've made it in the world if we send our kids to private school.
3. The 'can't let down the family tradition' argument - from parents who went to private school themselves and therefore feel they are letting themselves and their parents down if they don't send their kids their.
4. The pushy grandparents argument - where one set of grandparents insists on paying for private education (whether or not they have any idea of the quality of schools available in local state and private schools). Often links to '3' but where just one parent (and set of grandparents) went to private school.
5. The 'just don't understand what quality in schools is' argument. In other words that a school must be better if it gets better overall grades, regardless of the intake. Rather than realising that the best school is the one where your child will make most progress (purely talking about academic quality here).
So there are all sorts of reasons why 'a fool may be easily parted from their money'. I've seen it loads of times, parents sending their kids to poor private schools when they could have sent them to better state schools. But of course ounce they've started paying for something they are loath to admit it isn't top quality.
Now none of this should be taken to imply that all private schools are poor. That's not the case. There are fantastic private schools, just as there are fantastic state schools. But there are also really poor private schools as well, ones that often hide they poor academic standards and coasting nature behind the nice middle class intake (who would do pretty well in any school).