中文摘要
近几十年来，公文式（Kumon）和西尔万（Sylvan）等私人辅导连锁机构迅速扩张。结合商业网点、家庭支出和学区考试成绩数据，我们研究了哪些人使用这些中心，以及这些中心如何影响学业技能。近一半的辅导服务使用者来自收入最高的十分位群体；亚裔和白人家庭购买辅导服务的可能性分别是黑人和西班牙裔家庭的五倍和两倍。交错处理双重差分设计表明，一个学区的首家连锁辅导中心开业后，全学区的数学和阅读成绩提高了0.02至0.03个标准差，而其成本远低于通常带来类似增益所需的公共支出。对白人和亚裔学生而言，数学效应最大，因此辅导中心进入扩大了种族间学业成绩差距，不过这种扩大效应在种族融合程度较高的学区较弱。这些私人投资使其使用者受益，同时加深了教育不平等，并塑造了州问责制度和家庭评判学校所依据的结果。
Abstract
Private tutoring chains like Kumon and Sylvan have expanded rapidly in recent decades. Combining data on business locations, household spending, and district test scores, we study who uses these centers and how they affect academic skills. Nearly half of tutoring users are from the top income decile, with Asian and White households five and two times as likely to purchase tutoring as Black and Hispanic households. A staggered differences-in-differences design shows the opening of a district's first chain center raises district-wide math and reading scores by 0.02-0.03 standard deviations, at a much lower cost than public spending typically producing similar gains. Math effects are largest for White and Asian students, so that center entry widens racial achievement gaps, though less so in more racially integrated districts. These private investments help their users, deepen educational inequality, and shape outcomes by which state accountability systems and families judge schools.