The Holes in the Chetty et al VAM Study as Seen by the American Statistical Association

This is an important article, which criticizes and deconstructs the notorious VAM study by Chetty et al. I refer to it as notorious because it was reported on the first page of the New York Times before it was peer-reviewed; it was immediately presented on the PBS Newshour; and President Obama referred to its findings in his State of the Union address only weeks after it first appeared.

These miraculous events do not happen by accident. The study made grand claims for the importance of value-added measures of teacher quality, a keystone of Obama’s education policy. One of the authors told the New York Times that the lesson of the study was to fire teachers sooner rather than later. A few months ago, the American Statistical Association reacted to the study, not harshly, but made clear that the study was overstated, that the influence of teachers on the variability of…