Using a dataset that includes over 17 million students from across all 50 states, we estimate the causal impact of making structural transitions into middle school (in grades 4, 5, 6, or 7) on student math and reading achievement trajectories. This dataset provides an ideal opportunity to engage in the valuable scientific practice of conducting…

Schools use an array of strategies to match curricula and instruction to students' heterogeneous skills. Although generations of scholars have debated ''tracking'' and its consequences, the literature fails to account for diversity of school-level sorting practices. In this article, we draw on the work of Sørensen and others to articulate and…