M. Danish Shakeel, Misty Gallo, Patrick J. Wolf
We present a descriptive comparison of trends in achievement and inequality across traditional public, public charter, Catholic, and Department of Defense schools in the U.S. Our sample includes 6,155,570 observations of 4th- and 8th-graders in math and reading between 2005 and 2024. We focus on changes in the 25th and 75th percentile scores of students in those school sectors on the National Assessment of Educational Progress, adjusted for key student demographics. Analysis of 96 overall achievement trends reveals that no school sector has experienced a meaningful reduction in its 75–25 performance gap over the entire course of our time series in either grade or subject. Achievement gaps are largest and widening most swiftly in the traditional public school sector, chiefly due to the declining annual trend for its low achievers at the 25th percentile. Most of this increase in inequality occurred prior to the COVID-19 pandemic, which merely accelerated the pre-existing trend. Charter trends are mixed, with minimal losses at the 25th percentile and moderate gains at the 75th percentile. The 75–25 student performance gap in the Catholic sector increased over the 20-year study period, driven by both increases at the 75th percentile and declines at the 25th percentile, much like in the traditional public school sector. The Department of Defense (DoD) schools are outliers in our study. Student achievement in DoD schools was higher in 2024 than in 2005 at both the 25th and 75th percentiles, with little change in the performance gap. Detailed subgroup findings appear in an appendix. We discuss potential causes and policy implications.