Teacher tenure has been a hot topic lately, thanks to the Vergara decision a couple weeks ago in California that found the state’s teacher tenure laws were unconstitutional. As I wrote at the time, the decision is unlikely to spur a wave of similar lawsuits across the country, in large part, because many states have or are in the process of revising their tenure laws to incorporate measures of teacher effectiveness when granting tenure—-unlike in California. Many critics of teacher tenure hailed the decision believing it will now be easier to remove ineffective teachers.
However, simply removing ineffective teachers will not positively impact student achievement if those teachers aren’t replaced by more effective teachers. Recent reports from the CALDER Center at the American Institutes of Research (AIR) shed an all too important light on this question. One such report on New York City found teachers were only slightly more likely to be denied tenure after the city revamped their tenure process following the 2008-09 school year—an increase from a 2 to 3 percent denial rate. Yet, the rate at which teachers were approved for tenure declined dramatically because many more teachers had their probationary period extended instead of having their tenure denied or approved. Prior to the tenure reforms, 94 percent of eligible teachers had their tenure approved. Following the tenure reforms, that rate dipped to just 56 percent.
While New York City’s new tenure law did not force ineffective teachers to leave the classroom, many chose to leave on their own. The CALDER report found teachers who had their probationary period extended were 50 percent more likely to transfer to another school and 66 percent more likely to exit the system compared with teachers in the same school who were approved for tenure.
While critics of teacher tenure would hold this finding up as a success of tenure reform, it would in fact be a failure if ineffective teachers simply replaced the departing ones. Luckily for the students this is not what has happened in New York City. The teachers who had their probationary period extended and then left the school were on-average less effective than the teachers who replaced them in terms of both value-added scores and principal ratings. And the differences in effectiveness was fairly substantial as well.
If these trends continue students in New York City will be much less likely to be taught by an ineffective teacher as less effective teachers leave the profession while being replaced by more effective teachers. As previous research has shown, this can have a substantial impact on student achievement but such an impact will not happen over night. As effectiveness data comes in from states across the country that have implemented more accurate teacher evaluation systems, it is clear there isn’t a large proportion of consistently ineffective teachers that should be removed from the classroom. In fact, the vast majority of teachers are quite good so the focus should be on improving the performance of all teachers. Such focus will likely have a significant impact on student achievement as well. Yet, removing consistently ineffective teachers shouldn’t be ignored either. Even if just a small proportion of ineffective teachers left the profession each year and are replaced by more effective teachers, over time the impact would compound, such that students 10 years from now would be much less likely to be taught by an ineffective teacher than a student today.
Reforming teacher tenure laws and creating more accurate teacher evaluation systems have the potential to improve the overall effectiveness of teachers– if done correctly– but such impacts will not happen overnight. It will take time to make a significant impact on the overall effective of our teachers but it will likely have a tremendous impact on the achievement of those students who are just entering our public schools. – Jim Hull