We are now entering a time period in which we might start to see a lot of studies released about the impact of new teacher evaluations. This incredibly rapid policy shift, perhaps the centerpiece of the Obama Administration’s education efforts, was sold based on illustrations of the importance of teacher quality.
The basic argument was that teacher effectiveness is perhaps the most important factor under schools’ control, and the best way to improve that effectiveness was to identify and remove ineffective teachers via new teacher evaluations. Without question, there was a logic to this approach, but dismissing or compelling the exits of low performing teachers does not occur in a vacuum. Even if a given policy causes more low performers to exit, the effects of this shift can be attenuated by turnover among higher performers, not to mention other important factors, such as the quality of applicants (Adnot et al. 2016).
A new NBER working paper by Julie Berry Cullen, Cory Koedel, and Eric Parsons, addresses this dynamic directly by looking at the impact on turnover of a new evaluation system in Houston, Texas. It is an important piece of early evidence on one new evaluation system, but the results also speak more broadly to how these systems work.