Are you aware that there are grade-free and exam-free schools out there and that they have been operating for decades?
Measuring the effectiveness of school systems is difficult because of selection bias, but I'm sure you could find some attempts (e.g. PISA) if you went looking.
Measuring the effectiveness of school systems is difficult because of selection bias, but I'm sure you could find some attempts (e.g. PISA) if you went looking.