Kang Leads Analysis of Raj Chetty Study


David KangValue-Added Research Center (VARC) Researcher David Kang presented an analysis of a groundbreaking 2012 study, which used value-added to measure teacher quality, to a group of VARC staff including VARC Director Rob Meyer on Wednesday, Jan. 15.

The study, “Measuring the Impact of Teachers,” was completed by Harvard economists Raj Chetty and John Friedman, and Jonah Rockoff, of Columbia University. It grabbed national attention, including a front page article in the New York Times, for estimating that the replacement of a poor teacher with an average one would raise the lifetime earnings of a classroom of students by about $266,000. Chetty’s work on teacher value added was cited by the American Economic Association as a reason for awarding him the 2013 John Bates Clark medal, one of the most prestigious prizes awarded in economics.

The study, actually two separate papers, showed with statistical analysis that “students with top teachers are less likely to become pregnant as teenagers, more likely to enroll in college, and more likely to earn more money as adults,” according to the Times. In response to their findings, the authors backed the use of value-added measures used for the evaluation of teacher performance.

In his presentation, Kang examined the methodology used by the study’s authors in proving the worth of value-added measurements used for teacher evaluation. For VARC staff, who create and operate value-added measurement systems used by school districts throughout the country as part of their teacher evaluation systems, it’s important to have an intimate familiarity behind the statistical details that support the validity of their work, Kang said.