Like all quasi-experiments, this one relies on an assumption that the treatment – here, teacher switching – is as good as random. I find that it is not: Teacher switching is correlated with changes in students’ prior-year scores
Pointer from Tyler Cowen.
Thus, Rothstein hopes to debunk a famous paper by Raj Chetty and others which claimed to shows that great teachers add a lot of value. My guess is that Rothstein will fail. It reminds me of when Bill Wascher and others debunked the Krueger-Card paper claiming to show that higher minimum wage laws do not reduce employment. Once a result is put into the literature by a high-status economist and the result supports progressive policy preferences, it becomes undebunkable.
And you’re right, I’m not being charitable to those who disagree.
But progressives are divided on this issue. Many see the Chetty et.al. research as part of a “war on teachers.”
Rothstein is a solid economist but it is hard not to read his own policy preferences into this. He is clearly pro-union (which is fine), and his research to debunk Chetty et al. clearly play into the unions’ preference which is the status quo, do not distinguish superstar teachers from lousy teachers–all are equal.
I always have more trouble buying results that are aligned with the author’s personal views. But this is the norm in economics, I’m afraid. Part of it is surely that authors are drawn to study questions that mean a lot to them, personally.