Teacher Labor Market Policy and the Theory of the Second Best
利用北卡罗来纳州某城市学区的教师申请和校长评分数据，估计教师与小学的匹配模型，发现教师和校长的偏好偏离了弱势学生成绩最大化目标，但两者结合反而使教师质量在优势与弱势学生间均衡分配；单方面纠正偏差的政策无效甚至有害，双管齐下才能显著提升弱势学生成绩。
Abstract We estimate a matching model of teachers and elementary schools with rich data on teachers' applications and principals' ratings from a large, urban district in North Carolina. Both teachers’ and principals’ preferences deviate from those that would maximize the achievement of economically disadvantaged students: teachers prefer schools with fewer disadvantaged students, and principals' ratings are weakly related to teacher effectiveness. In equilibrium, these two deviations combine to produce a surprisingly equitable current allocation, where teacher quality is balanced across advantaged and disadvantaged students. To close achievement gaps, policies that address deviations on one side alone are ineffective or harmful, while policies that address both could substantially increase the achievement of disadvantaged students.