The four-day school week has become one of the fastest-growing trends in American K–12 education, particularly in rural communities. By 2023, roughly 850 districts across 24 states had adopted the shorter week, up from about 600 before the pandemic. While the earliest adopters often pointed to cost savings, the post-pandemic surge has been driven by staffing concerns, with many local leaders claiming that the four-day week is an attractive perk that can help them recruit and retain teachers.
A new CALDER working paper by Andrew Camp, J. Cameron Anglum, Cory Koedel, Se Woong Lee, and Tuan Nguyen casts doubt on that claim. Focusing on Missouri, where nearly a third of districts have made the switch to the shorter week, the study pairs qualitative interviews with an event study and difference-in-difference analysis, finding a mismatch between perception and reality.
The authors begin by conducting interviews with 36 Missouri educators, including 20 superintendents, four principals, and a dozen teachers. Most of these respondents liked the idea of a shorter school week. Superintendents, in particular, saw it as an important benefit that expanded applicant pools and reduced teacher turnover. One superintendent told the researchers, “We can’t compete with salary, so we had to put things in place like the four-day to encourage [teachers] to stay.” Several respondents said that, in rural areas where salaries lag behind those in nearby suburban systems, the four-day week had become an essential recruiting tool. And one worried that not adopting it could put his district at a competitive disadvantage, as other local districts had already implemented the shorter schedule. Teachers tended to echo these positive assessments, praising the additional day for improving work-life balance or allowing more time for lesson planning.
Yet when the researchers turned to the data, they did not find positive effects of shorter weeks on teacher recruitment or retention. Using fifteen years of Missouri Department of Education administrative records, from 2008 to 2024, they examined teacher turnover, new hires, and the use of “out-of-field” teachers, which is a common indicator of staffing stress. Their analysis finds that the estimated effects of adopting a four-day week are negligible and statistically insignificant. They found no evidence that shorter school weeks reduce teacher exits either overall or in hard-to-staff fields like STEM and special education. Their best estimate is less than one fewer annual exit per 100 full-time teachers. Nor did the policy meaningfully increase the share of new hires, whether from other Missouri districts or from outside the state, and any small gains in one group were offset by losses in the other. Likewise, there was no reduction in the prevalence of out-of-field teachers. These null findings held up under numerous robustness checks.
How can a policy that practitioners say works result in no measurable impact?
The authors suggest several possibilities. Teachers may value the shorter week, but not enough for it to outweigh salary, location, or other considerations when deciding whether to take or keep a job. Or district leaders may be confusing correlation with causation, attributing improvements to the calendar change when other forces are at play. They also posit that confirmation bias could be causing leaders in four-day districts to notice and remember positive anecdotes about the shorter school week while discounting contrary evidence.
The findings of this study based on Missouri data align with a small but growing body of research from other states. Studies in Colorado and Oregon have also found null or negative effects on teacher recruitment and retention, and the one state-level study to show a positive effect, Arkansas, found it to be very small.
What is even more troubling is that four-day week are not good for student learning. The researchers cite prior research indicating that the policy harms student achievement, with most estimates showing losses of 0.02 to 0.09 standard deviations in test scores per year of exposure. While these effect sizes are small, they can compound over time into sizable learning loss.
The downsides to the four-day week—along with the limited upsides—may be why state policymakers are beginning to regulate school time more aggressively. In 2024, the Missouri legislature passed Senate Bill 727, which requires voter approval before large districts can adopt the four-day week and offers a modest funding boost to districts that keep a five-day schedule. Other states are also passing new regulations, such as Oklahoma, where lawmakers have taken steps to limit the growth of shortened weeks and clamp down on virtual or “off-site” school days.
If the aim is to strengthen the teacher pipeline, the authors argue, states and districts would do better to address the underlying causes of staffing challenges, particularly in rural areas, through competitive compensation, targeted incentives, and improved working conditions, rather than reducing instructional days. The four-day school week may be popular with many educators and communities, but research continues to indicate that it doesn’t yield the recruitment and retention boost its advocates promise. And the fact that it’s bad for student achievement should be weighed very, very seriously.
SOURCE: Andrew M. Camp, J. Cameron Anglum, Cory Koedel, Se Woong Lee, and Tuan D. Nguyen, “The Effects of the Four-Day School Week on Teacher Recruitment and Retention,” CALDER (2025).
Editor’s note: Adam also covered this study on a recent episode of our podcast, The Education Gadfly Show. The discussion starts at 23:10.
