A multi-state, student-level analysis of the effects of the four-day school week on student achievement and growth

Four-day school weeks are becoming increasingly common in the U.S., but prior research is ambiguous regarding their impacts on achievement. Using a difference-in-differences approach, we conduct the most representative student-level analysis to date of the effects of four-day weeks on student achievement and within-year growth using NWEA MAP Growth data. We estimate significant negative effects of the schedule on spring reading achievement (-0.07 SD) and fall-to-spring gains in math (-0.05 SD) and reading (-0.06 SD). The negative effects of the schedule are disproportionately driven by adoptions in non-rural schools and are larger for female students. For policymakers and practitioners, this study provides evidence supporting concerns about four-day school weeks’ effects on student achievement and growth, particularly in non-rural areas.