A quickie on teachers getting better with more experience. The long-held view was that teachers improve rapidly for two or three years, or at most five years or so, and then do not improve much past that. (On average, of course. Every individual is different.)
A paper entitled “Productivity Returns to Experience in the Teacher Labor Market,” is adding to the accumulating evidence that the average teacher keeps getting better for many years–especially in teaching math.
John Papay and Matthew Kraft tried out a variety of empirical specifications and put together the results in a neat picture. The top panel gives math results and the bottom panel gives results for reading.
It’s true that teachers improve very quickly in the first few years. But it’s also true that they continue to improve gradually thereafter. In the authors’ preferred model, about half of the return to experience shows up in the first five years and the rest is spread out over the rest of a career. Other models show the later-career gains being a little less, but still there.