Less Is More? The Causal Effect of Four-Day School Weeks on Teacher Turnover

The use of four-day school weeks (4dsw) in the United States has expanded rapidly over the past two decades. Previous work examines the impact of 4dsw on student outcomes, but less research to date examines its effect on teachers even though schools in some locales have adopted 4dsw to improve recruitment and retention. This paper uses a difference-in-differences design to estimate the effect of 4dsw adoption in Oregon, a state with early and widespread 4dsw use, on teacher retention in both the short and long term. We find that adopting a four-day week increased turnover among teachers by approximately 2 percentage points overall. These increases are driven by schools that adopted prior to the COVID-19 pandemic and continue to impact schools in the longer term. The findings suggest that policymakers interested in implementing 4dsw for improved teacher retention should exercise caution.