We provide novel evidence on the causal impacts of student absences in middle and high school on state test scores, course grades, and educational attainment using a rich administrative dataset that tracks the date and class period of each absence. We use two similar but distinct identification strategies that address potential endogeneity due to time-varying student-level shocks by exploiting within-student, between-subject variation in class-specific absences. We also leverage information on the timing of absences to show that absences that occur after the annual window for state standardized testing do not affect test scores, providing a further check of our identification strategy. Both approaches yield similar results. We find that absences in middle and high school harm contemporaneous student achievement and longer-term educational attainment: On average, missing 10 classes reduces math or English Language Arts test scores by 3–4% of a standard deviation and course grades by 17–18% of a standard deviation. 10 total absences across all subjects in 9th grade reduce both the probability of on-time graduation and ever enrolling in college by 2%. Learning loss due to school absences can have profound economic and social consequences.

我们使用丰富的管理数据集来跟踪中学和高中学生缺勤对州考试成绩，课程成绩和教育程度的因果影响，从而提供新颖的证据，该数据集可以跟踪每次缺勤的日期和上课时间。我们利用两种相似但截然不同的识别策略，通过利用班级缺勤的学生内部，受试者之间的差异来解决因时变的学生水平的冲击而导致的潜在内生性。我们还利用缺勤时间的信息来表明，在州标准考试的年度窗口之后发生的缺勤不会影响考试成绩，从而进一步验证了我们的识别策略。两种方法产生相似的结果。我们发现，初中和高中的缺席会损害同时期的学生成绩和较长期的教育水平：平均而言，缺少10堂课会使数学或英语语言测试成绩降低标准偏差的3-4％，而课程成绩则降低17-18％标准偏差的百分比。9年级所有科目总共缺勤10次，使按时毕业和上大学的几率降低了2％。因缺课而造成的学习损失可能会产生深远的经济和社会后果。