Plan 21 , educational reforms in Shinagawa, arose some difficulties for educational studies. First, its school choice policy, which came to be initiated by the educational board, had been proposed by political intention to cope with the declining birthrate and the urban problem. Second, it enables more actors like parents, community residents, school leaders, and local authorities to participate in educational decision-making in different ways. Third, educational board comes to maintain the quality or educational content.// One of the clues to overcome these difficulties is the concept of " good ". Although education tends to be regarded as a public good, it satisfies no conditions of public goods in economic usage. Public economists call s...