Parental Responses to Public Investments in Children: Evidence from a Maximum Class Size Rule
利用瑞典学校最大班级规模规则导致的班级规模变化，研究发现高收入家长在班级扩大时增加辅导，而低收入家庭孩子更感学习困难，表明公共与私人教育投资存在替代关系。
We study differential parental responses to variation in class size induced by a maximum class size rule in Swedish schools. In response to an increase in class size: (1) only high-income parents help their children more with homework; (2) all parents are more likely to move their child to another school; and (3) only low-income children find their teachers harder to follow when taught in a larger class. These findings indicate that public and private investments in children are substitutes, and help explain why the negative effect of class size on achievement in our data is concentrated among low-income children.