Turns out, it does exist!
By way of Audrey Amrein-Beardsley, we learn:
Overall, Deming failed to reject the hypothesis that school-level effects as measured using VAMs are unbiased, almost regardless of the VAM being used. In more straightforward terms, Deming found that school effects as measured using VAMs are often-to-always biased.
Read more about the study and what it means for the validity of VAM-based teacher evaluation.
It’s worth noting that Deming’s findings suggest that school-based effects can be accurate predictors of student achievement — which has important implications for teacher-based effects. That is, school-level factors may be accurate predictors while assigning effect to teachers is more tenuous.
More on VAM:
For more on education politics and policy, follow @TheAndySpears