Educational Researcher (2011: vol. 40, no. 6, p. 271-80) just published an excellent article by Gary Henry (UNC-CH), Kevin Bastian (UNC-CH), and C. Kevin Fortner (GA State) titled “Stayers and Leavers: Early-Career Teacher Effectiveness and Attrition.”  The researchers examined teachers and test scores from North Carolina public schools.

Henry and his associates asked a critical question.  Do measures of teacher effectiveness increase because the early-career teachers acquired on-the-job skills or because less effective teachers left the profession?  The latter may be “exaggerating the apparent returns to teacher experience in estimates for early-career teachers who remain in the classroom.”

The authors concluded,

1. On average, teachers substantially increase their effectiveness between their first and second years of teaching.

2. For teachers who remain in the profession for at least five years, returns to experience generally flatten after the third year of teaching.

3. Frequently, teachers who leave after their first year are less effective than those who continue teaching into their second or later years.

4. Teachers who leave after their third or fourth year are less effective in their final year of teaching, on average, than teachers who continue teaching into a fifth year.

5. The performance of teachers who leave after their third or fourth year of teaching often drops. (p. 271-2)

What is the takeaway?  First, teachers who exited the profession were less effective than those who stayed.  This suggests that teacher attrition can be beneficial.

Second, teacher effectiveness plateaus after the third year of teaching.  This is a serious concern.  After all, we want to teachers to continue to refine their skills through mid-career.  Moreover, if tenured teachers are not necessarily better teachers, then they do we pay them more?  The obvious answer is that North Carolina’s teacher pay scale is based on credentials and experience.  The state pays experienced teachers more because they assume that experience makes teachers more effective/valuable than someone at the lower end of the scale.  If this is not the case, then we should pay teachers differently.