This research by Neild, Stoner-Eby, and Furstenberg used survey and student record data for a cohort of Philadelphia public school students. The authors found that ninth-grade outcomes add substantially to the ability to predict dropouts. They recommend that schools looking to decrease dropout rates focus on the high school transition year. This research may be particularly useful to districts or schools looking at ninth-grade indicators to predict those students at risk of dropping out of school.
Connecting entrance and departure: The transition to ninth grade and high school dropout
Education and Urban Society