Four-day school weeks have proliferated across the United States in recent years, reaching over 650 public school districts in 24 states as of 2019, but little is known about their implementation and there is no consensus on their effects on students. This study uses district-level panel data from Oklahoma and a difference-in-differences research design to provide estimates of the causal effect of the 4-day school week on high school students’ ACT scores, attendance, and disciplinary incidents during school. Results indicate that 4-day school weeks decrease per-pupil bullying incidents by approximately 39% and per-pupil fighting incidents by approximately 31%, but have no detectable effect on other incident types, ACT scores, or attendance.

近年来，为期四天的学校周在美国激增，截至 2019 年已覆盖 24 个州的 650 多个公立学区，但人们对其实施知之甚少，对其对学生的影响也没有达成共识。本研究使用俄克拉荷马州的地区级面板数据和差异研究设计来估计为期 4 天的学校周对高中生在校期间的 ACT 分数、出勤率和纪律事件的因果影响。结果表明，为期 4 天的学校周将每个学生的欺凌事件减少了约 39%，将每个学生的打架事件减少了约 31%，但对其他事件类型、ACT 分数或出勤率没有可察觉的影响。