The Goldhaber study above tries its best, but the only school-level variable they can pin down is that having lots of white kids in your school improves test scores.
And as far as I can tell, they don’t look at socioeconomic status of the school or its neighborhood, which is probably what the white kids are serving as a proxy for.
In order to say more than this we have to have a more precise way of identifying exactly which teachers are good, which is going to be more complicated. Suppose you want to figure out which teachers in a certain district are the best.
You know that the only thing truly important in life is standardized test scores , so you calculate the average test score for each teacher’s class, then crown whoever has the highest average as Teacher Of The Year. But you’ll probably just give the award to whoever teaches the gifted class.
Teachers have classes with very different ability, and we already determined that grit explains more variance than teacher skill, so teachers who teach disadvantaged children will be at a big, uh, disadvantage. Instead of judging teachers by average test score, we can judge them by the average change in test score.
Add like fifty layers of incomprehensible statistics and this is the basic idea behind VAM (value-added modeling), the latest Exciting Educational Trend and the lynchpin of President Obama’s educational reforms.
[Epistemic status: This is really complicated, this is not my field, people who have spent their entire lives studying this subject have different opinions, and I don’t claim to have done more than a very superficial survey.
I welcome corrections on the many inevitable errors.] I.
A few studies that we’ll get to later do suggest teacher experience matters; almost nobody wants to claim certifications or degrees do much.
One measurable variable not mentioned here does seem to have a strong ability to predict successful teachers.