Providing strong support for making better tenure decisions, a new study of teachers in the Charlotte-Mecklenburg school district finds a teacher's performance in just the first year of teaching is highly predictive of later performance.

The study examined value-added data for novice teachers in the district over five years, finding that teachers who were top performing in their first year as compared to other first-year teachers were top performing relative to their peers in their third year. Those who were in the bottom half in their novice year were still low performing in their third year.

The study also found significant differences between teachers graduating from top and bottom ranked universities, with teachers from higher ranked universities producing bigger gains.

And like many studies before it, the study finds once again that teachers' performance improves significantly in the first three years, and then levels out.

In related research, one of the most promising papers delivered at the most recent AEFA conference in Richmond, Virginia, was one delivered by newbie economics professor Ben Ost out of Cornell University. He reports that new teachers who are assigned to the same grade for the first few years of teaching improve a lot faster than new teachers who are switched around from grade to grade. This finding is particularly significant, as Ost finds that nearly a third of all teachers in his sample were assigned to teach two different grades in their first two years of teaching.