Does Shortening the School Week Impact Student Performance?

School districts across the United States have employed a variety of policies and programs to help close budget gaps. In particular, the four-day school week has been used to reduce overhead and transportation costs. The four-day week requires substantial schedule changes as schools must increase the length of their school day to meet minimum instructional hour requirements. This policy has been in place for many years in rural school districts in western states such as Colorado and Wyoming, and it appears to be gaining popularity nationwide. As of 2011, roughly 10 school districts in California used a four-day week.

There are many reasons why we might expect a shorter school week to impact academic performance. Previous researchers have found that longer class periods give teachers flexibility to organize lessons more effectively and incorporate varied teaching methods; in some districts, the day off is devoted to teacher planning and enhances faculty collaboration. From the perspective of students, a four-day week may increase attendance, limit distractions, improve morale, and lead to better behavior. On the other hand, the longer school days may increase teacher stress and fatigue and could be particularly demanding for younger students. Some worry that it is difficult for students to retain subject matter when given an extra day off.

To better estimate the costs and benefits associated with switching to a shortened school week, it is critical for school district and state education administrators to understand how this schedule change impacts student achievement. Yet few evaluations of the four-day week have been conducted; to date, the existing evidence has been anecdotal or descriptive in nature. This descriptive work is potentially flawed by factors that are simultaneously correlated with student performance and a district’s decision to switch schedule. For example, if the four-day schedule were adopted in school districts where scores were already on an upward trend, the effect of the schedule change would be confounded with this trend.

In this study, to more rigorously evaluate the four-day school week, we used a difference-in-differences regression framework and data on 4^th grade reading and 5^th grade mathematics test scores from the Colorado Student Assessment Program (CSAP). Over one third of the school districts in Colorado have adopted the four-day schedule. Our approach compares changes in test scores for a “treatment” group (i.e., schools that switched to a four-day week) to changes in test scores for a “control” group (i.e., schools that remained on a standard schedule) to estimate the relationship between the four-day school week and test scores. Our models also control for local economic conditions and school characteristics such as the student-teacher ratio and the racial composition of the student body.

In general, we found a statistically significant increase in math achievement after the introduction of a four day week. The relationship between the schedule change and reading achievement was also positive, although it was not statistically significant by the usual benchmarks. These positive effects, combined with robustness checks designed to address selection bias, suggest there is little evidence that switching to a four-day week harms student performance. Although our data do not support a full analysis of the underlying mechanisms responsible for better test scores, some preliminary investigations suggested the four-day school week may increase attendance rates.

Because our results are based only on data for smaller and more rural districts, a wider adoption of the policy across more densely populated areas would be required for a more general interpretation of the effects.

The full study is in: D. Mark Anderson and Mary Beth Walker (forthcoming). “Does Shortening the School Week Impact Student Performance? Evidence from the Four-Day School Week,” Education Finance and Policy. An ungated version is available here.