1.Through standardized testing to ensure the students are actually learning the mandated curriculum. 2. Barries to entry should be low. Maybe teachers must simply be able to pass the standardized tests themselves? I'm not sure what you mean by fungibility here? And I think this system would reduce monopolies in education since schools could choose whatever methods parents preferred, which encourages different approaches. Also the monopolies of the current system, government education departments and religious institutions, would be financially penalized if they underperformed and parents choose alternatives.