When teachers know their students well, they can teach more effectively, writes Fordham's Nathaniel Grossman.
When teachers and students are together for two or more years -- intentionally or accidentally -- students learn more, concludes a new study of Tennessee students from 2007 to 2017.
Only 2 percent of elementary teachers are "loopers," moving with the same group to the next grade, writes Grossman. However, "a high school math teacher might teach algebra to freshmen, geometry to sophomores, and precalculus to juniors."
Overall, 44 percent of students had at least one repeat teacher over the course of their education, usually in the upper grades, the study found. Having a repeat teacher was linked to higher test scores, especially in math, and fewer absences and suspensions.
High performers and white females made the largest academic gains, while "lower performing students and Black and Hispanic males saw the largest reductions in absences, truancy, and suspensions," writes Grossman.