At least here in the US, test prep isn't actually effective at increasing test scores. The SATs were introduced in order to allow kids of lesser economic backgr

At least here in the US, test prep isn't actually effective at increasing test scores. The SATs were introduced in order to allow kids of lesser economic backgrounds to get access to prestigious colleges without having to go to expensive preparatory schools. And they have been largely successful in that regard. The problem in the US is that, for political reasons, colleges have been trying to get away from standardized tests.