We examine the efficiency implications of imposing proportionality in teacher evaluation systems. Proportional evaluations force comparisons to be between equally-circumstanced teachers. We contrast proportional evaluations with global evaluations, which compare teachers to each other regardless of teaching circumstance. We consider a policy where…

Value-added modeling continues to gain traction as a tool for measuring teacher performance. However, recent research (Rothstein, 2009a, 2009b) questions the validity of the value-added approach by showing that it does not mitigate student teacher sorting bias (its presumed primary benefit). Our study explores this critique in more detail.…

This study uses administrative data linking students and teachers at the classroom level to estimate teacher value-added to student test scores. We find that variation in teacher quality is an important contributor to student achievement--more important than has been implied by previous work. This result is attributable, at least in part, to the…